I began programming my picaxe. I came into some problems...
1) When i ran the servos program (at 75) it only turned a quarter of an inch in that direction.
a. the servos cant be turned past that direction manually either
2) When I tried running the high and low commands
a. one wheel turned slightly and stopped
b. the board went hot so i quickly disconnected it and took out the batteries
The servos issue is beyond me. Does the board getting hot while attempting to run the motors imply there is a short on the board? Back to soldering? (this is my first time and there is a fair chance they suck) What should I resolder in that case and have I destroyed my board?
I was playing with my robot the other day and encountered something like this. I used servo 0,75 to initialize the servo (sets the timer used for the pulses I am told). In the old days, I used
servo 0, 75
servo 1, 75,
servo 2, 75
To initialize my servos then dropped into a routine that centered them using the servopos command.
If I recall I used servopos 0, 149.
Later I happened to put a pause command into the code and … one arm when HIGH, one arm went LOW, the head turned all the way to one side and every servo …buzzzzzed.
The value of 75 moves the servo to one extreme of its range. Try using 150 for the initialization value.
In regards to your board getting hot, I wired my battery back backwards the first time and that got it VERY HOT.
Of course you have some movement, so maybe that is OK, in which case I would be suspicous the motors are not turning and pulling MUCH power.
Try hooking the motors directly to a battery back, one at a time, just to see them work normally before trying to run it all through the board.
There is a specific place to plug the motors in if you are using the motor driver chip. You might need a jumper to enable that.
I would go over instructions for the START HERE robot and the tip on the picaxe 28x1 development board carefully. Not hard to make a mistake the first time you do this.
I was discussing this with my tech savvy brother and (brace yourself for mild retardation) I had soldered 3 of the motor pins in such a way that the solder was encompassing all 3. I assume is the problem and have to remove the solder with a solder remover (or turkey baster- as it was described to me).
Thanks for your reply about the servos. I’ll be playing with it as soon as I get the board back in order.
Good to hear you figured it out. Sounds like you shorted and it drew a lot of current through the board, thus making it hot. I appreciate you telling us what happened, always nice to know the answer and to know you figured it out.
Good luck with the rest of your project, so far I have been finding robots to be a blast.
I desoldered the pins which were done together. Then ran commands for the servos to make sure I didn’t destroy the board. It still doesnt turn left, and cant be forced in that direction. I ran high 4 low 5- and instead of turning slightly it didnt move at all. The other motor runs perfectly. I soldered and resoldered the connections to the first motor. Whats happening?
tell your servo to center itself without having the servo horn installed. Once you have done that, install the servo horn, and, you should get 180* of motion give or take.
I did that. It still wont turn much to the left and cant be forced by hand past that direction by hand. Further when I put in the batteries, the servos turns to the right slightly upon its insertion. Any thoughts on why one of my wheel motors isnt responding?
Servos usually twitch when power is first applied. This is because they are getting power before they are getting a clear signal about what postion to be in. I agree with the advice you received about being sure you have centered your servos before you put the servo horn on.
Regarding your motor issues, I suggest you isolate the symptoms and test. Try connecting the batteries directly to the motor wires (nothing else). Does the motor turn? Try testing the other motor with the suspect motor output pins.
Double check that you have each of the four motor pins connected correctly. Read through the Picaxe for Dummies post. Note that one motor’s leads should be across the two pins labeled ‘A’, and the other motor’s leads should be across the two pins labeled ‘B’. If you have the motors connected instead so that one lead from each motor is connected to the ‘A’ pins and the other lead from each motor is connected to the ‘B’ pins, you will get weird results.
THANK YOU. The problems with the servos have subsided but it took working with my hands- and not programming. The pin problem is isolated to a motor pins- should they be resoldered?
Impossible to say without a clear, in focus picture. Or if you have a multimeter, you can disconnect everything from the board and run a continuity test between the pins to be sure they are not shorted.
