Counter red light

I need a sensor that counter a number of impluses. This impluses was genered by a red led.
Now use the devduino and a small sensor (TP-12 Optical Pulse Sensing Probe for Energy Monitoring), but not work very when use 3.3 volts.
Is work very well, when use 5 volts.

Why not use 5v??


Because the devduino work with two battery type AAA.

After looking at the specifications, I would like to see how you have connected it.

Specifically which model do you have?


On further looking, I think you may have the RS232 version. If so your problem will probably be the RS232 standard. The standard requires a certain minimum voltage to work. 3.3v may simply be too low to power the sensor.


Yes, now I used Tp-12.

But have problems to counter when used 3.3V. The switch not stabilized signal output.

I try two diferentes modes, digital read and interupt mode.

Please give the full model number and supply a drawing of how it is connected.


I solved.


How about letting us know how and why!



Change port input digital to analog. Now, I reading analog port input state for sensor.