Hi,

I need to create a small testtool for explosion sensors. These sensor uses a BPX 61 photodiode.
I want to control the intensity of a 3 mm led with an arduino nano. But I can't directly use the PWM signal because my photodiode sees also a blockwave. The current through the diode must be constant but I need to be able to adjust the current so the intensity changes. Does anyone have an idea?

Thanks,
Jef

 

If it can't be PWM use a DAC with a resistor to drive the LED.

 

Welcome to AAC!
Use a low-pass filter to smooth the PWM, then use the resulting DC voltage to drive a constant-current source.