I'm programming a quite big Programm which is meant to control a model boat autonomously.
At the Moment my Servo Pins do quite stranage things:
I'm using the Arduino Servo library. If I tell my Servo to go to the middle (or the Motor to go to zero speed) they continuously receive pulses to go in a certain direction. The Servo is turning to full 180 (or zero...I didn't exactly check which direction it is going) and back to the middle then to 180 again and back to the middle and so on. And the Motor is howling up as well, goind back to idle, howling up again ... Other positions except them around the middle position (so around 90) work just fine.
I checked the code twice, there is not even a command in the code which pushes these values so high.
I tried to add stronger external power which didn't work either.
I wrote a new little sketch only telling both Servo and Motor to go to the middle/zero speed ... it worked fine.
The variables in my navigation sketch are using around 75% of the RAM of the UNO-board. Might this be the problem?
Bad grounding/wiring or malformed servo control pulses can cause servos to operate erratically. If the servos are making noise, they are possibly trying to turn against the internal mechanical stops. How are the servos powered?
Sorry I didn't think to post it, because I found nothing special about it that might lead to the problem since I commented out the actual navigation method in the setup, so that the servo values are set once and not change from that point. But since it still doesn't work and it seems to be about the code here it is:
The Servo is powered by the UNO-Board (5V and GND) and is connected to digital pin 5
The Motor is Powered by its own battery via a ESC which is connected to a GND-Pin and and digital pin 3
But as the problem does not show up when using a very simple basic code I believe there can't be too much wrong with the wiring.
Robin2:
Servos should always get a continuous stream of pulses. It is the width of the individual pulses that defines the position.
...R
Yeah right But that was not quite what I meant. Sorry for the bad wording. Here by 'pulse' I meant the continuous change between maximum and middle position not the actual pulse of the PWM Signal.
Don't ever power a servo from Arduino 5V, you will damage something and you'll certainly
get random or repeated resets as the servo pulls large currents and crow-bars the supply
voltage.
OK thank you. I'm powering it with the BEC from the ESC now.
But unfortunately the original problem's still not solved by that
Update:
I commented out all the GPS and SoftwareSerial compomemts. The Problem is gone. Might it be possible that the Arduino can't send a straight PWM-Signal to pin while reading information from another pin or while running a while-loop (as used in the getPos() method)?
Update: It has turned out that the Problem is a conflict between the SoftwareSerial and the Servo library. Everytime the SoftwareSerial receives data from the GPS module, the Servo freaks out.
coolaturon:
Update: It has turned out that the Problem is a conflict between the SoftwareSerial and the Servo library. Everytime the SoftwareSerial receives data from the GPS module, the Servo freaks out.
This is a well known problem - and illustrates the importance of making ALL the information available and not just the bits that seem relevant to you.
But that was not quite what I meant. Sorry for the bad wording. Here by 'pulse' I meant the continuous change between maximum and middle position not the actual pulse of the PWM Signal.