Hello all,
First post here.... Be gentle!
I'm working on automating the aircon/HVAC system in an old car, and I've decided to use a few RC servos to control the air control flaps.
I've got a NodeMCU to control, and a PCA9685 16-channel PWM board to control the servos (TowerPro MG946R). I'm trying to control 5 of the servos from the PWM board, but am having some troubles getting started. I've followed the Adafruit guides and using their libraries and sample code to get the thing working.
The problem I'm having is trying to get the unit to work using the external 5V supply to the PCA9685 board. When I have it connected (to a 5V 2A supply) I can't get anything to work (even 1 servo), but when I remove the power supply and connect the V+ pin to the NodeMCU Vin (basically bridging the Vcc and V+ on the PCA9685) it works and the servos move. But when I remove the bridge and try and power externally it doesn't. I'm using the sample "servo" code supplied with the Adafruit library.
Any ideas on what this could be? I'm totally at a loss....
Cheers,
Tim
How do you have it wired up? I assume you've looked at this Adafruit page.
I had the same issue the first time I used the pwm board, the board and motors need a common ground for the pwm signals to be sent. Good luck with your project!
wildbill:
How do you have it wired up? I assume you've looked at this Adafruit page.
Yes, I have thanks.
Hexanoob:
I had the same issue the first time I used the pwm board, the board and motors need a common ground for the pwm signals to be sent. Good luck with your project!
Thanks, I tried that. I haven't seen any other tutorials mention that, though.
Hi,
I managed to get it to work by providing 5V from an external supply to the V+ pin of the PCA9685 board.
I suspect that the block terminal on my board is dodgy....
Cheers,
Tim
You shouldn't need a common ground if you're powering through the separate power on the board. If i remember right, when i did share this it didn't work. It sounds like it could be a dodgy block as you said.
I have 5v powering my controller, then power, ground, sda and scl coming from that to the PCA. The red light on the PCA should come on to show its working. Then bring in the separate power for the servos. I hade 5v 700a powering 5 micro servos and it didnt really work. 1 did. So switched it for 5v 5a and all servos now work.
Do you have a multi meter to test?
Try building your own board...easier....cheaper...and you will be able to troubleshoot it