Arduino Issue

[RafBR]

Hi,
I noticed an issue with arduino. Maybe is just my Uno but only you can say.
I was trying my optocoupler (which I recently assembled on a breadboard) and then when playing with the potentiometers I noticed that when turning it slightly and slow back and forth, the leds (that lit for test) dont do that smooth. At least for one direction.
I swaped the direction jumper wires directly on the arduino outputs and the problem goes to the other direction, letting no doubt the source of the problem is the direction output pins on arduino.

Tried to reprogram arduino for use of other pins but the issue persists.

I have not my camera around now but is happening, lets say a red and green light, green light starts to dimming and when its almost gone it bright again before the red one to take place. Get it? Weird ha!

If I put a wiper motor on place this spike signal can be deadly bad for the h-bridge. It happens for both motors outputs.
And it seems to not appear on the pot reading over x-pid inteface. Seem to be an output issue.

If anyone saw anything like that please advice please!

[RacingMat]

Hi RafBR!

It's not very clear without pictures: the leds you're talking about are located on the ARduino or Hbridge?

Are you using PWM signal from Arduino to HBridge?
If it is the case, you shouldn' t be afraid of any "spike" signal. It will simply be a jump to full speed, nothing deadly for you Hbridge!

Could you tell us what kind of opto-isolator you're using ?
Mat