anders jepsen asked 5 years ago
Hey.
I’m planning on trying to get an esp32 to control my beer-brewing machine.
It’s got 12 pinch valves in there, which are controlled by servos (mg996r).
They are set by a pwm signal, and originally – when opening or closing the valves, it runs a short 1-2 second period of providing 5v to the servo, and sending the pwm signal. After this, everything goes back down – both the 5v supply, and also the pwm signal. The open/close positions of the servo are neither in a fully open or fully closed position. (5833 is the closed posistion)
I’m trying to figure out what the best way is, to mimic this behaviour :
A:
ledcAttachPin(16,3); ledcWrite(3,5833); delay(1000); ledcWrite(3,0);
Or B:
ledcAttachPin(16,3); ledcWrite(3,5833); delay(1000); ledcDetachPin(16);
with B I do have to reattach the pin with every call, but does it use less memory or power??
Sara Santos Staff answered 5 years ago
Hi Anders.
I’m sorry for taking so long to get back to you.
Your question was lost in so many other question we have here. I apologize for that.
I never did that experiment. But for what I read, servo motors are supposed to receive PWM signals continuously. If you detach PWM, it may hold the position, go to some random position or other unpredictable behavior.
However, I suggest that you experiment both codes and see how your motors behave. But I think the most “correct” way is option A.
Can you test it and then, tell me the results?
Regards,
Sara
anders jepsen answered 5 years ago
Hey – thanks for your reply.
What I was afraid of, was that if I just use option A, then the servo would go to a a third position (corresponding to “0”).
I think what I will end up doing, is use another pin to turn the 5V supply for the servos on/off – then I should be safe.
Anyways, again thanks for your input 🙂
Regards
Anders