Let's Make Robots!

Start Here Robot Urgent Issue

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?




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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 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.


            Good luck,




sounds like it wasn't centered to start with.