Arduino Uno constantly putting out voltage on output pins

Using Arduino Project Guidance
1

Hi Guys

I have been setting up a few led light systems and seem to have run into a bit of a problem.

I have (had) 2 identical LED driver boards with 4 Meanwell LDD1000H's on each one.

http://www.meanwell.com/search/LDD-H/LDD-H-spec.pdf

The LDD's require a 5V PWM signal to go to full brightness and 0V to switch off. The drivers run at 100% without any PWM.
The first board works 100% and with the grounds tied into each other but when I applied power to the second board my second bank of lights didn't illuminate :frowning:

I checked the output voltage from the UNO and found constant voltages on some pins even after clearing the code :

Pin 0 - 3.9V
Pin 1 - 3.6V -3.8V
Pin2 - 0V
Pin3 - 0.93V
Pin4 - 1.81V
Pin5 - 0V
Pin6 - 3.48V
Pin7 - 1.27V
Pin8 - 0V
Pin9 - 0V
Pin10 - 0V
Pin11 - 0V
Pin12 - 0V
Pin13 - 0.5V

I use the following to clear the code :

void setup(){
}
void loop(){
  analogWrite(3,0);
  analogWrite(5,0);
  analogWrite(6,0);
  analogWrite(9,0);
  analogWrite(10,0);
  analogWrite(11,0);
}

The LDD's on the second board is now reading 500 Ohm down to earth on the PWM input channel where as the first board reads 1500 Ohms.... The second board now no longer works at all. I have checked the grounds, and double checked but no voltage is read on the outputs.

The boards were both working without the PWM but now it seems something has gone haywire and blown 4 drivers as well as the UNO :frowning: I have had a look at the voltage regulator and seem to be getting the correct voltages from the UNO.

Will I be able to just replace the ATMEGA 328P

2

Will I be able to just replace the ATMEGA 328P

Replacement chips w/bootloader are available from multiple sources, one:

Disconnect thee UNO, replace the uC, attempt to download the blike sketch to test.

I am not familiar with your other hardware, so I cannot answer specifics on it... You may try the support forum for the vendor of those boards.

3

To test the outputs from the Arduino, use a sketch which simply sets all the relevant pins to output and digitalWrite them to zero in setup. Then next try writing them high.

If they function normally as digital outputs, the only reason they will misbehave in analogWrite is because there are a limited number of timers which can be used for this function.