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Servo is not going (updated with a picture), Picaxe 28x1


I programmed my picaxe using axepad for the mac.

servo 0,100  

But nothing happens,  the only movement I ever see is when I put in the batteries into the picaxe the connected servo moves slightly no matter which pin the servo is plugged into.  Is there something I am missing?  Is there something that tells a servo/picaxe to go or start?

Thank you,


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Could your servo be at position 100? That means that your code will not bring any change. No change in position = no movement.

Write a program that changes the position between two or more values. nd read the manual. You will need two Basic command: "servo" and "servopos".

Well the servo is modified for continous roation so I figured it would just start turning .

Unless it was modified to center "no move" @ position 100 which is unlikely though... Any pictures of setup? what is your wiring?

Yes, here is a picture of the picaxe 28x1 attached to my original post.

How you connected your servo to the picaxe 28x1? From the picture it seems you are using the Darlington driver output (Or the servo signal input is even not connected to anything?) This will not work. You must connect the servo signal input directly with the digital output of the picaxe, using a protective resistor (330 Ω) between.

I had a simillar problem at first, try this 


servo 0,170

pause 1000

goto main 


for some reason the pause helped me so...

Tried that, downloads my code successfully and then nothing. Is there a special chip I need for servos? I updated my original post with a picture.


It appears to me you have there a darlington driver chip. You need a 330 Ohm resistor from Picaxe output pin to servo signal line in order to drive it. So, Remove that chip, and place a resistor across terminals of dip socket as shown in picture below and you should be OK. Good luck.

Thank you, I had a feeling I was doing something wrong in this area. Now, I plan on hooking up 3 additional servos. In the picture, is your drawing corresponding with the 0 pin specifically?  And in this case would I need a 330 ohm resistor for pins 1, 2 and 3 to hook in servos as well?

Thank you.

Yes, you will need a 330 Ohm resistor for each servo. You can use single resistors, but the best way is to get one of these:

DIL 330 x 8 resistor array or this:

Picaxe Servo Upgrade Pach including this chip and servo.

Either way if you go for array, make sure to read servo upgrade pack's manual as it shows how to correctly install the chip.

Did I sound like Revolutional Education sales man?? :D

Hope to see your project on LMR soon!