As a small project, I wanted to try to get my pulse read by my arduino. I have tried use LDRs with superbright LEDs, but it seems that many of the existing projects use IR leds. I do have an IR led, but not a detector... the LDRs I have only "see" visible light. I also tried using an op-amp to amplify my heart's voltage, but this didn't seem to work (I also kept getting mains 60Hz interference). I'm also not sure how I should set up the op amp. Differential amplifier? Inverting amplifier? I think I'll get something like
this or
this, but for now, does anybody have any ideas? I have is two LM358s, some LEDs (including an LDR), an assorment of resistors, and some other general components.