We're using two pulsesensors 5V and one Arduino (we have a Nano and a Duemilanove, this occurs on both).
What we need to do is sample two pulses, and each has its own digital output as well.
If all the Arduino does is Serial.Write, we're golden, they each work great, output is accurate for both sides.
Here's where our problems start:
We have two output pins, if we use digitalWrite on them, suddenly the feedback from the sensors is disrupted and they affect each other, to the degree where one works alright but when trying the second pulsesensor, it sets off both sensors as if they're both receiving synchronized inputs! At first we thought this was an output problem, but when printing serial outputs it seems that the pulsesensors themselves are giving off wrong results, in that one is affecting the other. However, this can be isolated to some degree with software; but it's not a solution, since we need to continuously receive inputs from both sensors.
We're new to Arduino and hardware in general, and think that this issue may stem from some sort of feedback when writing to digital outputs. Maybe we should add something to the connection between Arduino and sensor, or Arduino and the output to avoid sending back wrong signals? No idea.
We've tried to connect both to two relays, but for debugging we've also tried regular LEDs, still the same issue, this problem is clearly visible when using LEDs.
This message was originally posted to: http://pulsesensor.proboards.com/index.cgi?board=ijustgotmypulsesensorand&action=display&thread=74#ixzz1xMWHJrAI
but to no avail
Thanks for your time, and we'd appreciate any help given. Please help!