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Can't get my HXT900 servo to move


Trying to get my HXT900 to work on my test board but it just screams. I'm using a PICAXE 08M pins 0,1,2. there is a jumper that i set to downlaod and then to use as low for servo. orange cable to pin 0, red cable to pin1 and brown cable to pin2 The following is my code. Anyone out there ever came across this . Note I had it working once on my 18M



low 0

high 1

servo 2,75 'initialise servo


pause 2000 ' wait 2 seconds

servopos 2,225 ' move servo to other end

pause 2000 ' wait 2 seconds

servopos 2,150

pause 2000 ' wait 2 seconds


goto main




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   I have a couple of blog posts and a demonstration video relating to servo power here -




Its all Arduino based, but the same constraints apply to many boards.

Duane B


It is just as Chris said.

Hook the red power wire to the plus (+) side of the supply, the minus of the servo (brown or black) to the minus (-) side of the supply and only ONE wire, (the yellow or white wire from the servo) to the picaxe. Only one pin from the picaxe turns the servo on or off.


If I am reading this right, you have the servo's ground wire to output 0, power to output 1 and signal to output 2. In this configuration, you are trying to power the servo via output pins. This is not good.

Your servo will draw FAR more current than those output pins can deliver and a couple things can happen (or not happen). First, your servo is just not going to have enough juice to move. Second, the picaxe (in whole or in part) is going to become fried. As a matter of fact, I would not be surprised if it is currently fried (at least output 0 and 1).

Disconnect this now! Use your outputs for "data level" signals only and don't try to run motors off of them!

Never thought of it that way, was just trying to see if it works thanks Chris