{"id":8418,"date":"2021-12-18T12:27:31","date_gmt":"2021-12-18T17:27:31","guid":{"rendered":"https:\/\/dronebotworkshop.com\/?p=8418"},"modified":"2023-04-12T06:30:54","modified_gmt":"2023-04-12T10:30:54","slug":"myoware","status":"publish","type":"post","link":"https:\/\/dronebotworkshop.com\/myoware\/","title":{"rendered":"MyoWare Muscle Sensor"},"content":{"rendered":"\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-9571 size-full alignnone\" title=\"Download PDF\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2023\/04\/dbws-pdfdown.png?resize=64%2C64&#038;ssl=1\" alt=\"Download PDF\" width=\"64\" height=\"64\" data-recalc-dims=\"1\" \/> <a href=\"#Parts_List\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9563 size-full\" title=\"Parts List\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2023\/04\/dbws-parts.png?resize=64%2C64&#038;ssl=1\" alt=\"Parts List\" width=\"64\" height=\"64\" data-recalc-dims=\"1\" \/><\/a> <a href=\"https:\/\/youtu.be\/wMVL3d2dN9U\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9565 size-full\" title=\"View on YouTube\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2023\/04\/dbws-youtube.png?resize=64%2C64&#038;ssl=1\" alt=\"View on YouTube\" width=\"64\" height=\"64\" data-recalc-dims=\"1\" \/><\/a> <a href=\"https:\/\/s3.amazonaws.com\/download.dronebotworkshop.com\/MyoWare+-+DroneBot+Workshop.zip\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9569 size-full\" title=\"Download Code\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2023\/04\/dbws-codedown.png?resize=64%2C64&#038;ssl=1\" alt=\"Download Code\" width=\"64\" height=\"64\" data-recalc-dims=\"1\" \/><\/a><\/p>\n<p><span style=\"font-weight: 400;\">Today we are going to work with a rather unique sensor, the <a href=\"https:\/\/learn.sparkfun.com\/tutorials\/myoware-muscle-sensor-kit\" target=\"_blank\" rel=\"noopener\">MyoWare Muscle Sensor<\/a>.<\/span><\/p>\n<p>&nbsp;<\/p>\n<div class=\"youtube-player\" data-id=\"wMVL3d2dN9U\"><\/div>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">This cool device can allow you to perform electromyography experiments on yourself and other unsuspecting subjects!\u00a0 If you\u2019re unsure as to what electromyography is, then read on.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8387\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<h2><span style=\"font-weight: 400;\">Introduction<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">There&#8217;s a good chance that at one point in your life you have had an EMG test in a clinic, hospital, or doctor&#8217;s office.\u00a0 This non-invasive test is performed for a number of medical reasons.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The technology to perform these exams is very expensive, as most medical equipment is, and is generally out of reach to most experimenters. That hasn\u2019t been a very big concern, as not too many of us really want to build an EMG device anyway.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">But the same technology that is used in conducting an EMG test can also be used for other things. Some examples include:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Gesture sensing<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Robot control<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Exoskeleton design<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Total immersion video games<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">In addition to all that, it\u2019s just very interesting to experiment with!<\/span><\/p>\n<p><span style=\"font-weight: 400;\">These applications don\u2019t require the same precision that a hospital EMG requires, and they can be performed with much cheaper equipment.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Today, we will be examining a sensor kit that allows you to perform your own EMG experiments, as well as create some very fascinating devices.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Electromyography<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">A complete description of Electromyography is beyond the scope of this article, however a basic description follows.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Motor Neurons<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The whole process centers around <\/span><i><span style=\"font-weight: 400;\">Motor Neurons<\/span><\/i><span style=\"font-weight: 400;\">, which are located in your brain and in your spinal cord.\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8392\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/motor-neurons.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/motor-neurons.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/motor-neurons.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Every time your brain wants to move a muscle, it uses motor neurons to transmit an electrical signal to them. These electrical signals cause the targeted muscle to contract.<\/span><\/p>\n<p><i><span style=\"font-weight: 400;\">Electromyography<\/span><\/i><span style=\"font-weight: 400;\"> is the process of sensing electrical activity produced by skeletal muscles.\u00a0 An instrument that performs electromyography is called an <\/span><i><span style=\"font-weight: 400;\">Electromyograph<\/span><\/i><span style=\"font-weight: 400;\">.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8382\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/electromyograph.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/electromyograph.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/electromyograph.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">An electromyograph measures those faint electrical signals. In practice, sensors are placed along the path of the neurons. The electromyograph picks up these signals and measures both their speed and strength.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The record produced by an electromyograph is called an <\/span><i><span style=\"font-weight: 400;\">Electromyogram<\/span><\/i><span style=\"font-weight: 400;\">, and the entire procedure of getting one is commonly referred to as an <\/span><i><span style=\"font-weight: 400;\">EMG<\/span><\/i><span style=\"font-weight: 400;\">.\u00a0<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Electromyographs<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">You have probably had an EMG at least once in your life, they are a common medical diagnostic test. Other uses for electromyography include medical research and muscle training.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">An electromyograph machine typically costs several thousand dollars and requires the expertise of a trained medical professional to use and interpret its readings.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The sensors used in an electromyograph are typically temporary stick-on electrode pads, however, electromyographs can also use sensors that are permanently attached to a body, or even inserted into the skin to measure electrical signals within the body.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Until recently, these experiments and procedures were restricted to hospitals and clinics that can afford both the equipment and trained personnel to operate it. However, the advancement in low-cost sensors has now made it possible to conduct these experiments for a much lower cost.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">This has opened up electromyography to experimenters, makers, and developers, who can use this low-cost equipment to create new and exciting applications.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Now, of course, this low-cost equipment is not as sophisticated or as accurate as the machines used in hospitals to perform EMGs. However, it is still useful in its own right.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The MyoWare muscle sensor kit that we will be using today is an example of some of this low-cost equipment.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">MyoWare Muscle Sensor Kit<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The MyoWare Muscle sensor is built by Advancer Technologies and packaged by Sparkfun. It consists of the following items:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">MyoWare Muscle Sensor &#8211; The heart of the kit, which we\u2019ll be looking at in detail today.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">LED Shield &#8211; An attachment shield with an LED bargraph display and a rechargeable battery.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Power Shield &#8211; A shield with slots for two CR2032 coin-cell batteries, to power the sensor.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Cable Shield &#8211; This shield allows you to attach external electrodes to the MyoWare sensor.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Proto Shield &#8211; A blank shield that can be used for prototyping.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Electrode Cable &#8211; The cable that connects to the Cable Shield. It has three electrodes.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Sensor Pads- Monitoring electrode pads to use with the electrodes.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">The kit also includes a number of connectors that you can solder to the sensor and shields in order to mate them together.\u00a0 It\u2019s a good idea to do this before you start using the boards.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Muscle Sensor<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The main component in the kit is the MyoWare Muscle Sensor itself. This is the latest generation of a sensor that has evolved over several years, so you might still find information regarding previous versions when you are researching it on the internet.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8404\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-muscle-sensor-headers-top.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-muscle-sensor-headers-top.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-muscle-sensor-headers-top.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The Sparkfun version of the MyoWare sensor is a wearable board that has two electrode connectors on the bottom. These attach to standard monitoring electrode pads, and are labeled \u201cmiddle\u201d and \u201cend\u201d.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8416\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-sensor-pinout-bottom.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-sensor-pinout-bottom.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-sensor-pinout-bottom.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">There is also a small cable attached to a third pad, which is the \u201creference electrode\u201d.\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8417\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-sensor-pinout-top.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-sensor-pinout-top.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-sensor-pinout-top.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The sensor circuit board has connections for power, signal out, raw data, and external electrodes. These connections are meant to be attached to female connectors, which will allow you to stack the other shields directly onto the sensor board.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">On the top of the board you\u2019ll also find a power switch and a gain control, which can be adjusted to increase the sensitivity of the sensor.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The board has a power LED, as well as an LED that indicates when a signal has been detected.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The MyoWare Muscle Sensor operates on 2.9 &#8211; 5.7 violets DC, so it is compatible with virtually all microcontrollers.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">LED Shield<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The LED Shield\u2019s most prominent feature is a 10-element LED bargraph display, which indicates muscle activity when paired with the MyoWare sensor.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8399\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-led-shield-top.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-led-shield-top.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-led-shield-top.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">This shield also has a rechargeable battery, so it can also power the muscle sensor.\u00a0 A microUSB connector on the board can be used to recharge the battery.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Power Shield<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The Power Shield is a very simple device, consisting just of two battery holders. This allows you to use two CR2032 coin-cell batteries to power the MyoWare muscle sensor and other shields.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8406\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-power-shield.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-power-shield.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-power-shield.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">It is very important to note that you should never use this board in conjunction with the LED shield, as they will both attempt to provide power and will conflict if used together.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Cable Shield<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The Cable Shield is also a pretty simple board. It has a 3-conductor. 3.5mm jack that is used with a mating cable assembly.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8395\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-cable-shield-headers-bottom.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-cable-shield-headers-bottom.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-cable-shield-headers-bottom.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The cable assembly has the three electrodes (middle, end, and reference) on it, and extends approximately 100 centimeters (40 inches).\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">This cable allows you to place the electrodes on parts of your body that are not conveniently accessed using the wearable sensor. You should note, however, that the cable is not shielded, so it may pick up interference in areas with high electrical noise.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Proto Shield<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The Proto Shield is simply a blank perfboard that is cut to the same form factor as the MyoWare sensor. It has space for the three connectors used for all the shields.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8409\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-proto-shield.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-proto-shield.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-proto-shield.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">You can use this board to prototype your own external circuits for use with the MyoWare muscle sensor.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Using the LED Shield<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The easiest way to get started with the MyoWare muscle sensor is to mate it with the LED Shield. As this shield has its own power source, it&#8217;s simply a matter of mating the two together.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8386\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-parts.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-parts.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-parts.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">When you do join the shield to the sensor, pay particular attention to getting it the right way around, as it will fit both ways. The pins on the connector are labeled, so use those markings to ensure you have installed the shield correctly.\u00a0\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">It\u2019s also a good idea to turn the MyoWare muscle sensor off while mating it to the LED, or to any shield.\u00a0<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Getting Prepared<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">After attaching the LED Shield to the MyoWare sensor, you\u2019ll need to get ready to use the assembly. This involves attaching three pads to the electrode connectors, two on the sensor itself and a third one on the short black electrode, which is the reference sensor.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8388\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-power-test.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-power-test.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-power-test.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">You are better off attaching the pads to the electrode connectors first, as opposed to placing them on your body and attaching the electrodes later.\u00a0 This makes it easier to align the pads on the sensor, plus it reduces the chances of bruising the skin.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Before you place the pads on your body, you\u2019ll need to determine exactly where to place them! I suggest starting with your arm, flex some muscles (squeezing your hand closed is a good method) and observe your arm to see the muscular movement.\u00a0 The place you see a lot of activity is a good place to start.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Clean the area with isopropyl alcohol first, to remove any dirt or skin oils. Then peel the protective paper off of the back of the electrode pads and mount the MyoWare sensor directly on your skin.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8385\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-attach-pads.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-attach-pads.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-attach-pads.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The reference electrode should be placed somewhere where there is NO muscle activity, as its purpose is to establish a baseline reference.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Now we are ready to use the MyoWare muscle sensor!<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Using the MyoWare Muscle Sensor<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">With the MyoWare muscle sensor and LED Shield firmly attached to your arm, or wherever you are taking your measurement, turn on the power switch. \u00a0 Try and relax your muscles as you do this.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8387\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Initially, the LEDs on the LED Shield will all illuminate, and you&#8217;ll observe a lot of activity. Within a few seconds, it will calm down, with only one LED lit (or possibly none). Again, try and relax your muscles as best you can.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">This initial activity is normal, the muscle sensor is stabilizing itself using the reference probe.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">After the display has settled down, try flexing the muscle you are measuring. You should see the LED bargraph display the results. The more you flex the muscle, the higher the bargraph will read.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Experiment with the MyoWare muscle sensor and LED Shield combination by placing the electrodes in different spots and observing the results.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Using External Probes<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">The Probe Shield allows you to use remote electrode sensors with the MyoWare muscle sensor.\u00a0 These are connected to a 3.5mm jack on the shield.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">We can stack this shield in between the MyoWare sensor and the LED Shield. Once again, be sure to observe the correct orientation by looking at the pinout markings on all three boards when you do that.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8379\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-continuity-test.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-continuity-test.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-continuity-test.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Before you mount the shield, however, you should confirm which electrode goes to which sensor input &#8211; middle, end or reference.\u00a0 You can do this with a multimeter, measuring continuity to the R, E, and M pins on the connector on the side of the shield.\u00a0 Make a sure you don\u2019t have the shield plugged into any other board while performing this measurement.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The measurements on my cable were as follows:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Black &#8211; Reference Electrode<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Red &#8211; Middle Electrode<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Blue &#8211; End Electrode<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">According to Sparkfun, there can be differences in the color-coding of the shields. They have a <\/span><a href=\"https:\/\/learn.sparkfun.com\/tutorials\/myoware-muscle-sensor-kit#cable-shield\" target=\"_blank\" rel=\"noopener\"><span style=\"font-weight: 400;\">chart on their website<\/span><\/a><span style=\"font-weight: 400;\"> page illustrating the differences, by this chart I seem to have a <\/span><i><span style=\"font-weight: 400;\">v11<\/span><\/i><span style=\"font-weight: 400;\"> cable version.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Once you know which wire is which, you can mount the shields. Be sure to keep the power switch OFF on the MyoWare muscle sensor board.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8381\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-test.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-test.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-test.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Place some pads on each electrode. Then peel off the backing from the pads and place them on the desired locations.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Now turn on the MyoWare sensor and observe the LED Shield bargraph display. Give it a few seconds to stabilize, then try flexing and relaxing the target muscle.\u00a0 You should see the results on the display.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8378\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-attach-pads.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-attach-pads.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/cable-shield-attach-pads.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The external probes make it much easier to experiment with the MyoWare Muscle sensor, and they can be used with or without the LED Shield.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">On that subject, let&#8217;s see how we can use the MyoWare muscle sensor with a microcontroller.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Connect to an Arduino<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">We will be using an Arduino Uno for these experiments for no particular reason, as any microcontroller with analog inputs will do just fine. In fact, using a more advanced microcontroller like an ESP32 or Raspberry Pi Pico would have advantages, as their analog to digital convertors have more precision than the Uno. But, as everyone probably has a Uno I\u2019ll go with that, you can substitute a different microcontroller if you wish.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Safety Considerations<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Before we hook up a microcontroller (any microcontroller) to the MyoWare muscle sensor, we need to discuss safety.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">When operating on batteries, the MyoWare muscle sensor is completely safe, as there is no electrical connection to AC ground and the voltages used are very small and low-current. The muscle sensor itself does not transmit any electricity to the electrodes, it works the opposite way. Think of them as very sensitive voltmeters, or the inputs to very sensitive audio amplifiers.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">But, when attaching an external device like a microcontroller, or using an external power supply, you run the risk of connecting the negative (GND) input of the MyoWare sensor to AC ground.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Under normal circumstances this is not an issue, after all, the very purpose of the AC ground is to establish a baseline reference for the AC power in your home or office.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">But a wiring fault, ground loop, or voltage leak in the system can raise the potential of the AC ground.\u00a0 And that could pose a safety hazard.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8412\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-battery.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-battery.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-battery.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Connecting a battery-powered microcontroller, like an Arduino Uno using a 9-volt battery, would be completely safe, as once again there is no path to AC ground.\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8413\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-cpu.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-cpu.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-cpu.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">But connecting via a USB cable to a computer, as you do when programming and testing an Arduino, runs a risk as you make an AC ground connection via the USB cable.\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8414\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-notebook.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-notebook.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-notebook.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Using a battery-powered notebook or laptop computer to connect to the USB cable is fine, as once again, there is no connection to AC ground. Be sure not to connect any external accessories, such as an external video monitor, to the computer.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8415\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-usb-isolator.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-usb-isolator.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-safety-usb-isolator.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">But you CAN safely use a desktop computer (or AC-powered notebook computer) with a microcontroller without passing through an AC ground. You just need a device called a \u201cUSB Isolator\u201d.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Adafruit USB Isolator<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The Adafruit 100ma USB Isolator is the perfect board for the job. It will allow you to connect your Arduino, or other microcontroller, through USB without passing a common ground.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8372\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/adafruit-usb-isolator-diagram.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/adafruit-usb-isolator-diagram.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/adafruit-usb-isolator-diagram.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Of course, to maintain this isolation you\u2019ll need to ensure that you don\u2019t allow any additional source of AC ground to connect to the microcontroller, this would defeat the purpose of the isolator.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The Adafruit device is small and very simple to hook up. It has two connectors:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Input<\/b><span style=\"font-weight: 400;\"> &#8211; a microUSB connector is used as an input connector, so you\u2019ll need a microUSB cable.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><b>Output<\/b><span style=\"font-weight: 400;\"> &#8211; A standard USB type A connector. For the Arduino Uno, you\u2019ll need a USB type A to B cable, like the one that probably came with your Uno (and every other Uno you ever purchased).<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">There is also a small switch on the USB Isolator for speed, labeled HIGH and LOW. There are instructions for its use on the back of the board. I used mine in \u201cHIGH\u201d speed, and it worked fine, the instructions allude to issues with timing for keyboards and mice.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8371\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/adafruit-usb-isolator.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/adafruit-usb-isolator.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/adafruit-usb-isolator.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Using this isolator is as simple a plugging it in. If you don\u2019t find that it passed enough current (as I initially did) try using a powered USB hub between your computer and the USB isolator. That seemed to fix it for me.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Arduino &amp; MyoWare Hookup<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The hookup is shown here, as you can see it\u2019s about as simple as it gets.\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8393\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-arduino-hookup.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-arduino-hookup.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-arduino-hookup.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">I\u2019m not showing the USB isolator, but you\u2019ll need it unless you\u2019re using a battery-powered computer. In this experiment, you\u2019ll need an external computer, as we require the serial monitor.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Arduino &amp; MyoWare Code<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Just as the hookup is very simple, so is the code. All we are doing is reading the analog input and displaying its contents to the serial monitor, without modification.<\/span><\/p>\n<pre class=\"lang:c++ decode:true \" title=\"Myoware Muscle Sensor Test\">\/*\r\n  Myoware Muscle Sensor Test\r\n  myoware-test.ino\r\n  Demo of Myoware Muscle Sensor\r\n  Output to Serial Monitor\r\n  Use battery-powered computer or USB isolator for safety!\r\n  DroneBot Workshop 2021\r\n  <blockquote class=\"wp-embedded-content\" data-secret=\"m9R5FIMucJ\"><a href=\"https:\/\/dronebotworkshop.com\/\">Welcome to the Workshop!<\/a><\/blockquote><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"&#8220;Welcome to the Workshop!&#8221; &#8212; DroneBot Workshop\" src=\"https:\/\/dronebotworkshop.com\/embed\/#?secret=gY3RTj2vo9#?secret=m9R5FIMucJ\" data-secret=\"m9R5FIMucJ\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\r\n*\/\r\n\r\n\/\/ Connection to Myoware sensor\r\n#define SENSOR_PIN 0\r\n\r\n\/\/ Integer for sensor value\r\nint sensorValue;\r\n\r\n\r\nvoid setup() {\r\n  \r\n  \/\/ Set up serial port\r\n  Serial.begin(9600);\r\n\r\n}\r\n\r\nvoid loop() {\r\n \r\n  \/\/ Read sensor value\r\n  sensorValue = analogRead(SENSOR_PIN);\r\n  \r\n  \/\/ Print value to Serial Monitor\r\n  Serial.println(sensorValue);\r\n}\r\n<\/pre>\n<p><span style=\"font-weight: 400;\">We define a connection to the analog input pin on pin A0 and an integer to hold the value of that input.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In the Setup, we initialize the serial port.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">And, in the Loop, we read the value of the analog input, assign it to our variable, and write it to the serial monitor.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">As I said, very simple!<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Load the sketch to your Arduino, power on your MyoWare sensor (the LEDs on the MyoWare sensor will indicate that you are getting power from the Arduino) and open the serial monitor.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">You should see a rapid display of numbers, that change when you flex the muscle you are measuring. It should get higher as you tighten the muscle.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">It\u2019s an interesting display, but a bit hard to read.\u00a0<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Serial Plotter<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">A better display for the output data from the MyoWare sensor is the Serial Plotter.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Close the serial monitor and open the serial plotter, it\u2019s the next item in the menu. You should now see a graphical representation of the analog input value, with the bottom (X) axis representing time and the Y-axis representing level.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">A big improvement over a stream of numbers, but still difficult to read. Difficult because the Y-axis does not stay fixed, instead it dynamically adjusts itself to the input level.\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8373\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/arduino-test-1.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/arduino-test-1.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/arduino-test-1.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">This makes it very hard to see rises and falls in the data, as they are compensated for as they happen.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">We need to try and fix that.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Improved EMG Plotter Code<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The problem with the Y-axis continually moving can be resolved by giving the plotter two other values to display:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">A lower limit of 0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">An upper limit of 1000<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">The following code does exactly that:<\/span><\/p>\n<pre class=\"lang:c++ decode:true \" title=\"Myoware Muscle Sensor Test - Plotter\">\/*\r\n  Myoware Muscle Sensor Test\r\n  myoware-test-plotter.ino\r\n  Demo of Myoware Muscle Sensor\r\n  Output to Serial Monitor\r\n  Use battery-powered computer or USB isolator for safety!\r\n  DroneBot Workshop 2021\r\n  <blockquote class=\"wp-embedded-content\" data-secret=\"m9R5FIMucJ\"><a href=\"https:\/\/dronebotworkshop.com\/\">Welcome to the Workshop!<\/a><\/blockquote><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"&#8220;Welcome to the Workshop!&#8221; &#8212; DroneBot Workshop\" src=\"https:\/\/dronebotworkshop.com\/embed\/#?secret=gY3RTj2vo9#?secret=m9R5FIMucJ\" data-secret=\"m9R5FIMucJ\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\r\n*\/\r\n\r\n\/\/ Connection to Myoware sensor\r\n#define SENSOR_PIN 0\r\n\r\n\/\/ Integer for sensor value\r\nint sensorValue;\r\n\r\n\r\nvoid setup() {\r\n  \r\n  \/\/ Set up serial port\r\n  Serial.begin(9600);\r\n}\r\n\r\nvoid loop() {\r\n \r\n  \/\/ Read sensor value\r\n  sensorValue = analogRead(SENSOR_PIN);\r\n  \r\n  \/\/ Add \"fake\" plots to stabilize Y axis\r\n  Serial.print(0); \/\/ To freeze the lower limit\r\n  Serial.print(\" \");\r\n  Serial.print(1000); \/\/ To freeze the upper limit\r\n  Serial.print(\" \");\r\n  \r\n  \/\/ Print value to Serial Monitor\r\n  Serial.println(sensorValue);\r\n}\r\n<\/pre>\n<p><span style=\"font-weight: 400;\">It\u2019s the identical code to the first one until you get into the Loop.\u00a0 There, we also print two \u201cfake\u201d output values to the serial port, one of them at zero and the other at 1000.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">You might wonder why not 1024 instead of 1000? The reason is the way the serial plotter scales, which would increase the scale to 1250 or 1500, which is a waste of space.\u00a0 The data seldom, if ever, will get to 1024.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8374\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/arduino-test-2-improved.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/arduino-test-2-improved.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/arduino-test-2-improved.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Load that up to the Arduino and repeat the first experiment, observing the serial plotter as you flex your muscle. The Y-axis of the display should now stay fixed at 0-1000, making it easier to reads the MyoWare muscle sensor data.<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Moving a Robot Arm<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">As a final experiment, I\u2019m going to attempt to control a robot arm with two MyoWare sensors.\u00a0 Spoiler alert &#8211; it didn\u2019t really work very well!<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">MeArm Robot Arm<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">A long time ago I put together a MeArm robotic arm, it\u2019s a kit of acrylic parts and MG-90 stepper motors that is really just for educational purposes, as it\u2019s not particularly capable of manipulating anything.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Since I had it around collecting dust (literally, I had to clean it off) I decided it might be fun to try and control a couple of the servo motors using MyoWare sensors.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8390\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/mearm-claw.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/mearm-claw.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/mearm-claw.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">The eventual goal was to have the arm mimic the motion my arm was making, but I didn\u2019t come anywhere near achieving that!\u00a0 But the fundamental design still has, I believe, some merit, so I\u2019m presenting it here.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">MeArm and MyoWare Hookup<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">The hookup is pretty simple, there is just a lot of wiring, but it\u2019s all quite straightforward.<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8400\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-mearm-arduino-hookup.jpg?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-mearm-arduino-hookup.jpg?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/myoware-mearm-arduino-hookup.jpg?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Essentially, you can break down the wiring as follows:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The two MyoWare muscle sensors &#8211; These connect to analog inputs 0 and 1.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The two potentiometers &#8211; These have their wipers connected to analog inputs 2 and 3.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The four stepper motors &#8211; These are BATTERY POWERED (no AC adapters for safety) and connect to four of the Arduino digital outputs.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The power &#8211; Make sure not t forget the common ground between the servo battery pack and the Arduino ground. Once again, keep safety in mind when wiring!<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">Observe all precautions as we did before regarding safety and using a USB isolator when developing. When you have the experiment \u201cfine-tuned\u201d to your liking, it\u2019s best to use everything battery-powered. The serial monitor is only used for diagnostics and isn\u2019t required for operation.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">The purpose of the two potentiometers is to just position the servo motors that we are NOT controlling. They can be trim-pots if you like, or you could eliminate them entirely and just use fixed values for those servos PWM outputs.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">MeArm &amp; MyoWare Code<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Here is the code we are using to control the MeArm with the two MyoWare sensors, and the two potentiometers.<\/span><\/p>\n<pre class=\"lang:c++ decode:true \" title=\"Myoware Muscle Sensor MeArm Demo\">\/*\r\n  Myoware Muscle Sensor MeArm Demo\r\n  myoware-mearm-demo.ino\r\n  Control two servos (Right and Claw) on MeArm with muscle control\r\n  Remaining servos (Middle and Left) controlled by potentiometers\r\n  Use only battery power for safety!\r\n  DroneBot Workshop 2021\r\n  <blockquote class=\"wp-embedded-content\" data-secret=\"m9R5FIMucJ\"><a href=\"https:\/\/dronebotworkshop.com\/\">Welcome to the Workshop!<\/a><\/blockquote><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"&#8220;Welcome to the Workshop!&#8221; &#8212; DroneBot Workshop\" src=\"https:\/\/dronebotworkshop.com\/embed\/#?secret=gY3RTj2vo9#?secret=m9R5FIMucJ\" data-secret=\"m9R5FIMucJ\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\r\n*\/\r\n\r\n\/\/ Include the Servo Library\r\n#include &lt;Servo.h&gt;\r\n\r\n\/\/ Define Servo Objects\r\nServo servoMiddle;\r\nServo servoLeft;\r\nServo servoRight;\r\nServo servoClaw;\r\n\r\n\/\/ Variables to hold servo positions\r\nint positionMiddle;\r\nint positionLeft;\r\nint positionRight;\r\nint positionClaw;\r\n\r\n\/\/ Myoware Sensor Inputs\r\n#define SENSOR1_PIN 0\r\n#define SENSOR2_PIN 1\r\n\r\n\/\/ Potentiometer Pins\r\n#define POT1_PIN 2\r\n#define POT2_PIN 3\r\n\r\n\/\/ Variables to hold sensor and potentiometer values\r\nint valueSensor1;\r\nint valueSensor2;\r\nint valuePot1;\r\nint valuePot2;\r\n\r\n\/\/ Variables to hold minimum and maximum PWM values for each servo motor\r\n\/\/ Determined through experimentation, adjust as required\r\nint minMiddle = 0;\r\nint maxMiddle = 180;\r\nint minLeft = 0;\r\nint maxLeft = 180;\r\nint minRight = 0;\r\nint maxRight = 180;\r\nint minClaw = 0;\r\nint maxClaw = 180;\r\n\r\n\/\/ Variables to hold minimum and maximum Myoware sensor values\r\n\/\/ Determined through experimentation, adjust as required\r\nint minSensor1 = 25;\r\nint maxSensor1 = 530;\r\nint minSensor2 = 0;\r\nint maxSensor2 = 1023;\r\n\r\n\r\nvoid setup() {\r\n\r\n  \/\/ Set up serial port\r\n  Serial.begin(9600);\r\n\r\n  \/\/ Attach Servo Motors\r\n  servoMiddle.attach(11);\r\n  servoLeft.attach(10);\r\n  servoRight.attach(9);\r\n  servoClaw.attach(6);\r\n\r\n  \/\/ Delay to allow Myoware sensors to stabilize\r\n  delay(5000);\r\n\r\n}\r\n\r\nvoid loop() {\r\n\r\n  \/\/ Get values from sensors and assign to variables\r\n  valueSensor1  = analogRead(SENSOR1_PIN);\r\n  valueSensor2  = analogRead(SENSOR2_PIN);\r\n\r\n  \/\/ Get values from potentiometers and assign to variables\r\n  valuePot1 = analogRead(POT1_PIN);\r\n  valuePot2 = analogRead(POT2_PIN);\r\n\r\n  \/\/ Compute servo positions for Middle and Left (driven by potentiometers)\r\n  positionMiddle = map(valuePot1, 0, 1023, minMiddle, maxMiddle);\r\n  positionLeft = map(valuePot2, 0, 1023, minLeft, maxLeft);\r\n\r\n  \/\/ Compute servo positions for Right and Claw (driven by Myoware sensors)\r\n  positionRight = map(valueSensor1, minSensor1, maxSensor1, minRight, maxRight);\r\n  positionClaw = map(valueSensor2, minSensor2, maxSensor2, minClaw, maxClaw);\r\n\r\n  \/\/ Position servo motors\r\n  servoMiddle.write(positionMiddle);\r\n  servoLeft.write(positionLeft);\r\n  servoRight.write(positionRight);\r\n  servoClaw.write(positionClaw);\r\n\r\n  \/\/ Write status to serial monitor for troubleshooting\r\n  Serial.print (\"Right Sensor = \");\r\n  Serial.print (valueSensor1);\r\n  Serial.print (\" - Right Position = \");\r\n  Serial.println (positionRight);\r\n\r\n  Serial.print (\"Claw Sensor = \");\r\n  Serial.print (valueSensor2);\r\n  Serial.print (\" - Claw Position = \");\r\n  Serial.println (positionClaw);\r\n\r\n  \/\/ Delay to prevent servo \"chattering\"\r\n  delay(20);\r\n\r\n}\r\n<\/pre>\n<p><span style=\"font-weight: 400;\">We start by including Arduino\u2019s built-in Servo library.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">We then define a number of variables and constants:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Objects to represent each servo motor<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Variables to hold the servo position, in degrees.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The two analog pins used for the MyoWare sensors<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The two analog pins used for the potentiometer inputs.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Variables to hold the values of the four analog inputs<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Variables to hold the minimum and maximum positions (in degrees) for each servo motor. Adjust to suit your application.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Variables to hold the minimum and maximum values from each MyoWare sensor. You\u2019ll need to come up with your own values from 0 to 1023 for these.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">For that last set of variables, you can use the previous experiment with the serial monitor, instead of the serial plotter. Run it for a while and flex your muscles! Then disconnect the Arduino but leave the serial monitor open. You can now scroll back and look at the data.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Determine the minimum and maximum values and use this in the code for the minimum and maximum sensor values. Do this for each sensor.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In the Setup, we initialize the serial monitor, which again is only for diagnostics. And we also attach the four servo motors to their Arduino I\/O pins.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Then we have a short delay, to prevent the servos from going crazy while the MyoWare sensors stabilize.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">In the Loop, we read the analog inputs and map them to their predefined limits, for both the MyoWare sensors and the potentiometers. Then we map the outputs to the pre-defined range we set earlier.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">We then write these values to all the servo motors.<\/span><\/p>\n<h3><span style=\"font-weight: 400;\">Testing &amp; Improving Performance<\/span><\/h3>\n<p><span style=\"font-weight: 400;\">Load the code into the Arduino, disconnect it, and then battery-power it.\u00a0\u00a0<\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-8391\" src=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/mearm-testing.png?resize=750%2C422&#038;ssl=1\" alt=\"\" width=\"750\" height=\"422\" srcset=\"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/mearm-testing.png?w=768&amp;ssl=1 768w, https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/mearm-testing.png?resize=300%2C169&amp;ssl=1 300w\" sizes=\"(max-width: 750px) 100vw, 750px\" data-recalc-dims=\"1\" \/><\/p>\n<p><span style=\"font-weight: 400;\">Hook up your electrodes to the position you notice your muscles moving when you make the required arm and fist movements. I had good luck capturing the arm movements, but terrible luck getting the arm flexing!<\/span><\/p>\n<p><span style=\"font-weight: 400;\">It will take some time to get this to work, especially the arm movement. It would be much easier to have two sets of cable shields and their remote electrodes, to give you more flexibility and to avoid pulling apart your experiment every time you flexed your muscle!<\/span><\/p>\n<h2><span style=\"font-weight: 400;\">Conclusion<\/span><\/h2>\n<p><span style=\"font-weight: 400;\">While I may have failed at mastering robot arm control, I did nonetheless find the MyoWare Muscle Sensor Kit to be both interesting and entertaining.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">To be able to even work with technology like this in a home environment was unthinkable not too long ago. This kit is the basis for a lot of fun and educational experiments.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">And I may just be able to control that robot arm one day yet &#8211; stay tuned!<\/span><\/p>\n<p>&nbsp;<\/p>\n<div class=\"dbwspartsbox\">\n<h3>Parts List<\/h3>\n<p><em>Here are some components that you might need to complete the experiments in this article. Please note that some of these links may be affiliate links, and the DroneBot Workshop may receive a commission on your purchases. This does not increase the cost to you and is a method of supporting this ad-free website.<\/em><\/p>\n<p>COMING SOON!<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"dbwsresourcebox\">\n<h3><span style=\"font-weight: 400;\">Resources<\/span><\/h3>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/s3.amazonaws.com\/download.dronebotworkshop.com\/MyoWare+-+DroneBot+Workshop.zip\"><span style=\"font-weight: 400;\">Code used today<\/span><\/a><span style=\"font-weight: 400;\"> &#8211; All the Arduino code used today, in a handy ZIP file!<\/span><\/p>\n<p><a href=\"https:\/\/learn.sparkfun.com\/tutorials\/myoware-muscle-sensor-kit\" target=\"_blank\" rel=\"noopener\"><span style=\"font-weight: 400;\">Sparkfun Guide<\/span><\/a><span style=\"font-weight: 400;\">\u00a0 &#8211; The MyoWare Muscle Kit guide from Sparkfun.<\/span><\/p>\n<p><a href=\"https:\/\/learn.sparkfun.com\/tutorials\/myoware-muscle-sensor-kit\" target=\"_blank\" rel=\"noopener\"><span style=\"font-weight: 400;\">Advancer Technologies<\/span><\/a><span style=\"font-weight: 400;\"> &#8211; GitHub page for Advancer Technologies. Get the latest MyoWare documentation here. <\/span><\/p>\n<\/div>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Today we will learn about electromyography by working with a MyoWare Muscle Sensor. <\/p>\n<p>We&#8217;ll see how to use this device and its shields in both stand-alone mode and with an Arduino.<\/p>\n","protected":false},"author":1,"featured_media":8387,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[9,90],"tags":[44],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/i0.wp.com\/dronebotworkshop.com\/wp-content\/uploads\/2021\/12\/led-shield-experiment-results.png?fit=768%2C432&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/s74ClK-myoware","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/posts\/8418"}],"collection":[{"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/comments?post=8418"}],"version-history":[{"count":11,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/posts\/8418\/revisions"}],"predecessor-version":[{"id":9840,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/posts\/8418\/revisions\/9840"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/media\/8387"}],"wp:attachment":[{"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/media?parent=8418"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/categories?post=8418"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dronebotworkshop.com\/wp-json\/wp\/v2\/tags?post=8418"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}