{"id":290,"date":"2017-12-17T12:31:24","date_gmt":"2017-12-17T10:31:24","guid":{"rendered":"http:\/\/thomaskosch.com\/?p=290"},"modified":"2017-12-17T12:34:25","modified_gmt":"2017-12-17T10:34:25","slug":"galvanic-skin-response-powered-by-arduino","status":"publish","type":"post","link":"https:\/\/thomaskosch.com\/index.php\/2017\/12\/17\/galvanic-skin-response-powered-by-arduino\/","title":{"rendered":"Galvanic Skin Response powered by Arduino"},"content":{"rendered":"<p>Recently, I have looked into how to measure electrodermal activity (EDA) using an Arduino board. A traditional theory of EDA states, that it varies with the skin changes of sweat glands, thus altering the electrical resistance. EDA is modulated as outcome of cognitive processes, emotions, and general human behavior. The traditional mechanic to measure EDA is straigt-forward: By inducing voltages through one electrode, an electrical output is measured using a second electrode.\u00a0The higher the measured value is, the higher the EDA is.<\/p>\n<p>This can be easily achieved using an Arduino. By using the 5V power to induce voltages, a second electrode is used to read the remaining voltages. For this project, you will need:<\/p>\n<ul>\n<li>An Arduino Uno<\/li>\n<li>Arduino IDE<\/li>\n<li>Processing IDE (for visualizing data)<\/li>\n<li>USB 2.0 A-to-B cable<\/li>\n<li>Some aluminium foil<\/li>\n<li>Velcro tape (self-adhesive tape)<\/li>\n<li>A couple of jumper cables<\/li>\n<li>Two 220 Ohm resistors (for experimental reasons)<\/li>\n<li>Some regular adhesive tape<\/li>\n<\/ul>\n<p>Put the components together as shown in the picture below:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-287 aligncenter\" src=\"http:\/\/thomaskosch.com\/wp-content\/uploads\/2017\/12\/setup.jpg\" alt=\"setup\" width=\"1920\" height=\"1440\" \/><\/p>\n<p>Connect one cable\u00a0from the 5V output of\u00a0the Arduino to a sensor. To construct a sensor, connect a jumper cable to a piece of wrapped aluminium foil. Wrap it around the Velcro tape, which will serve as\u00a0 a retainer for the fingers. Construct a second sensor, which is connected to the breadboard through two 220 resistors. Finally, connect a jumper cable to A0 on the Arduino board.\u00a0While one sensor induces electrical voltages, the\u00a0other one measures the remaining arriving electrical potential.<\/p>\n<p style=\"text-align: left;\">You will need some Arduino code (download <a href=\"http:\/\/thomaskosch.com\/wp-content\/files\/gsr.ino\">here<\/a>,\u00a0&#8220;Save link as&#8230;&#8221;) to read the analog value received at port A0.\u00a0The serial monitor should display the values sent over the serial port. I found some processing code on the web (thanks to\u00a0Che-Wei Wang,\u00a0<a href=\"http:\/\/cwwang.com\/2008\/04\/13\/gsr-reader\">http:\/\/cwwang.com\/2008\/04\/13\/gsr-reader<\/a>) to visualize the outcomes (download a slightly modified version <a href=\"http:\/\/thomaskosch.com\/wp-content\/files\/gsr.pde\">here<\/a>, right-click and choose &#8220;Save link as&#8230;&#8221;). Put one sensor on your forefinger and one sensor on your ring finger:<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\" wp-image-288 aligncenter\" src=\"http:\/\/thomaskosch.com\/wp-content\/uploads\/2017\/12\/2017-12-16-15.10.57.jpg\" alt=\"2017-12-16 15.10.57\" width=\"1831\" height=\"1373\" \/>Upload the Arduino software and run the processing software. You should get a graph visualizing you current EDA. You can modify the sensitivity of measured changes regarding the EDA by removing or changing the inserted resistors.\u00a0Try to understand how different resistances\u00a0modify the measured values.<\/p>\n<p style=\"text-align: left;\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-289 alignleft\" src=\"http:\/\/thomaskosch.com\/wp-content\/uploads\/2017\/12\/2017-12-16-15.17.00.png\" alt=\"2017-12-16 15.17.00\" width=\"902\" height=\"477\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Recently, I have looked into how to measure electrodermal activity (EDA) using an Arduino board. A traditional theory of EDA states, that it varies with the skin changes of sweat glands, thus altering the electrical resistance. EDA is modulated as outcome of cognitive processes, emotions, and general human behavior. The traditional mechanic to measure EDA [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-290","post","type-post","status-publish","format-standard","category-uncategorized","czr-hentry"],"_links":{"self":[{"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/posts\/290","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/comments?post=290"}],"version-history":[{"count":7,"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/posts\/290\/revisions"}],"predecessor-version":[{"id":297,"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/posts\/290\/revisions\/297"}],"wp:attachment":[{"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/media?parent=290"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/categories?post=290"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/thomaskosch.com\/index.php\/wp-json\/wp\/v2\/tags?post=290"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}