/challenges-projects/design-challenges/enchanted-objects/b/blog/posts/magichat---5---blood-pressure-sensorI made some modifications to the original circuit I talked about in my previous post and made it on a bread board. Here is the resulting circuit I placed my finger on the sensor, and I got a quite clean signal The signal is 200 mV ...en-USTelligent Community 12https://community.element14.com/challenges-projects/design-challenges/enchanted-objects/b/blog/posts/magichat---5---blood-pressure-sensorThu, 02 Apr 2015 15:13:51 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:ec1520f7-dc12-4471-bdc8-6561a8e2c4e2neilk0<p>This looks fantstic. I worked on pulse plethysmography for my Masters in Medical Electronics..........in 1972........we didn&#39;t have nice sensors like this them.</p><img src="https://community.element14.com/aggbug?PostID=20360&AppID=117&AppType=Weblog&ContentType=0" width="1" height="1">https://community.element14.com/challenges-projects/design-challenges/enchanted-objects/b/blog/posts/magichat---5---blood-pressure-sensorThu, 02 Apr 2015 12:34:38 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:ec1520f7-dc12-4471-bdc8-6561a8e2c4e2Workshopshed1<p>I was watching the EEV blog the other day and Dave was looking a.t an old speach recognition circuit. That used a comparator to turn audio into a square wave and the frequency was read directly via a digital pin on the microcontroller. Obviously if you are using the SAM to analyse the signal you might do that in software.</p><img src="https://community.element14.com/aggbug?PostID=20360&AppID=117&AppType=Weblog&ContentType=0" width="1" height="1">