I'm having some trouble controlling the movement of three servos. Two are continuous rotation and one is a high torque servo, all rated to run on 6V.
The problem is that whenever I connect the servos to a 6V battery they spin erratically at full speed. The continuous rotation servos are not so much a problem because they only move a very small amount. The high torque servo however appears to do a 180deg turn. This happens regardless of whether I'm running a sketch, or if I disconnect the signal wires and just connect the battery terminals directly to the servo.
Is this something intrinsic to all servos or am I missing some fundamentals here? How could I possibly fix it?
I would appreciate any advice here, even if it's a stab in the dark. Cheers.
It does sound like you haven't connected the battery ground to the arduino. I know you said you have but that is the expected behavior when you haven't.
waley:
Yes, I'm fairly sure I've grounded them all together. I have the grounds of the servos and battery connected in series to the ground on the Arduino.
The word series is either just a poor choice of word or you may not have it wired correctly. A drawing would help at this point.
When you power up a servo it will turn to its programmed position if not already there. If you power it down at a different position to 'home' its likely to do this.
MarkT:
When you power up a servo it will turn to its programmed position if not already there. If you power it down at a different position to 'home' its likely to do this.
This ended up being the issue, so thanks for replying I have been busy with the project the last couple of days and hadn't had time to reply to everyone else, but thank you everyone!
When I said I had all the grounds connected in series, I was meaning I had all the grounds connected in one column on a breadboard. Was this not the correct way to go about it?
When I said I had all the grounds connected in series, I was meaning I had all the grounds connected in one column on a breadboard. Was this not the correct way to go about it?
The wiring is correct. Parallel would be a better term than serial.
Both are wrong.
A better term would have been chain to describe the way the grounds are linked. The other way to do it is star where all the grounds meet at one point.
I have been busy with the project the last couple of days and hadn't had time to reply to everyone else, but thank you everyone!