Scotty, we need more power!
Carrying on from my previous post, I mentioned that Rob had let me borrow a .NET Gadgeteer pulse oximeter for a project that I am working on. When I got it all connected up and the drivers installed, I realised that I was getting what I am going to call “Ghost Readings”.
This was because the probe thought that it was attached even though it wasn’t and it would get readings of about 140 heart rate but the signal would be low. I then realised it was because there wasn’t enough power going through my USB to power the probe as well as the LCD screen (insert picture of sad face here). I was only really using the LCD for debug purposes so I disconnected it and I got it all working properly! The above screen cap is of a reading at a sort of steady level. I intend to do a little exercise and get some more readings.