Hi! I ordered a PCA9685 and I'm trying to connect five servos to it. I believe I am using the proper voltage and wiring, have tried a lot of tutorials and different code with it, ran an IC2 test and confirmed my board works, individually tested each servo with the standard servo circuit, but nothing seems to work.
I have tried to use Arduino IDE and Bottango, but nothing seems to make the servos move. What could be causing this issue? Below are images of my circuitry. Thank you!!
If that's one of the clone boards with the itty bitty SOT-23 MOSFEt's, 6 servos is more than enough to have blown it. And if it's one of clone boards with no reverse voltage protection MOSFETs, they don't have the most stellar reputation for working.
I'd be checking whether you've got 5V at the servo connectors. And not running it with 6 servos. You could get away with that with a real Adafruit one with the larger MOSFET, but not with any clone board I've seen.
Thanks for your reply! It is a cheap PCA9685 that I found on Amazon, but it does seem to still be receiving a signal and the power light is still on. I also ran an IC2 test with the Arduino and it is able to successfully detect the PCA9685. I have also tried it with just one servo with a fresh one, but they still won't move. What you've said is possible, but considering that everything else seems to be in working order, I'm not quite sure that's the issue.
If you didn't check to see if there was 5V at the servo connectors, you don't know that's not the issue. But hey, if you'd rather argue than check, it's your time. I'm done here.
PS blowing the MOSFET only removes 5V from the servo connectors. The servos don't move, but everything else still works.
Do you have the servo power connected to the PCA9685 correctly? Green is normally ground in my circuits. Reverse polarity won’t work. Been there. Done that.
Hmm, that could be the issue. Would my electronics already be damaged? If not, how would I reverse this so they will work properly? Sorry, I'm very new to this.
Reversing is easy, just swap the wires. If reversed you probably blew something.
What if my terminal has reverse polarity protection? Is there still a chance that it got blown?
I reversed the polarity on the servo power pins by accident. It did not damage mine. If anything, it might damage your servos.
Check the voltage between the V+ and GND pins. Should be around 5v.
If you don’t have an o-scope, you can connect a LED between the PWM and GND pins on an active channel, It should glow dim.
Or snap with diode overcurrent.
Try only using one servo at a time.
No worry about overcurrent. Every pca9685 I’ve seen has 220 ohm resistors on the 16 pwm outputs.
Solved: all the servos died. Yeah, IDK how i missed this. Remembered yesterday I ran too much current from them in the morning but I thought only one of them had shorted. Unfortunately, later tests proved wrong. I just set up the standard servo circuit on each of them individually and realized none of them were working. Too bad.
That's not possible, so you did something else wrong.
Better find out what before you burn out more servos.
Maybe, maybe not - tell us more about your testing. What if your "Standard servo circuit” approach is flawed, used a dead output pin, etc. etc.? After all, you’ve not shown us stellar technique so far, so why shouldn’t we be suspicious now?
