Pretty new to Arduino and received a Giga R1/Shield this past Friday to do a master clock project to drive an old Pragotron clock, I've managed to connect to WiFi, pick up NTP, synch the board to UTC plus offset, the display shows the times and a 'last pulse' variable of voltage/duration but my attempts to write code to address the 5v out directly at rail pin 5 (don't think I can) have failed and when trying to use A0-A5 and a PWM % approach with analogWrite I consistently crash the OS and get some red lights - the idea is to connect the controlled 5V out to a booster (that's happily providing constant 24.1V at the moment) and pulse it once every 60 seconds based on UTC seconds=00, alternating/reversing the polarity with each pulse, not super concerned about accuracy - probably missing something silly or have a fundamental design flaw but any thoughts on where I am stumbling?
I'm absolutely not familiar with the Giga; I know that it's a 3.3V board so I'm a bit confused about your attempt to get 5V out of a pin.
What do you mean by "rail pin 5".
Can the pins A0..A5 be used as PWM outputs on a Giga?
yes for my first foray into Arduino, the Giga might not have been best choice since relatively new it seems/not a ton of use best I can tell - the board has an analog rail with constant 5v out pin but seems it cannot be addressed/controlled directly via software so I've changed direction to use a couple of digital pins (I was stuck on analog and working A0-A5 when I posted, I think you can control those pin via other pins with PWM but not sure) and add a L293 to the circuit - using a DRV8871 I was able to get the positive pulse to work as expected but the negative pulse not so much, I am not entirely certain the lack of a negative pulse is a limit of the DRV8871 or my software skills, but based on looking around last night I think the L293 might be better suited and there are folks actually using it for this purpose but with different controllers (ie; ESP32) - I went with the Giga mainly because I wanted a display and the Giga Display Shield fits the bill and the Giga R1 nicely.
If you have not done so yet, I suggest that your download the pinout: https://docs.arduino.cc/resources/pinouts/ABX00063-full-pinout.pdf. The cheatsheet can also be useful.
Any pin that is marked with a '~' can be used for PWM; that would be D2..D13.
I assume that you are referring tot the pins marked 5V; those are power pins and can not be controlled. They are used to apply power to external 5V devices.
You will have to draw a wiring diagram and post it here (photo of paper and pencil drawing is OK); it needs to show all connections between your motor driver and the Giga as well as all GND lines and all power lines (3.3V/5V/12V whichever ones are used).
The PWM pins of the Giga provide a signal between 0V (LOW) and 3.3V (HIGH); they do not provide a -3.3V signal. Motor drivers as you use do not create positive/negative signals either; they can change the direction of a motor by "swapping" the signals to the motor.
With the below, the motor will e.g. turn clockwise.
out1 12V ------+
|
-+-
/ \
| | Motor
\ /
-+-
|
out2 0V ------+
And with this the motor will turn in the opposite direction
out1 0V ------+
|
-+-
/ \
| | Motor
\ /
-+-
|
out2 12V ------+
'out1' and 'out2' are the outputs of the motor driver.
hello again and thanks for taking the time to help out - I ended up replacing my H Bridge option with L298N, I am still uncertain if the DRV8871 was bad or my wiring was bad - the L298N ended up being easier to work with and I have it and the booster powered from Arduino 5V out, pin 22 to ENB on the bridge and 6/7 to IN3/IN4, OUT3/OUT4 go to the clock. I am playing around with accuracy now and some compensation code, the 'clunk' of the movement every minute is fantastic...
