Let's Make Robots!

Gear pager motor not enough power

Okay I am trying to hook up the gear pager motor to test it so I write the code as below:


high portc 3

wait 1

low portc 3

wait 1

goto main

I used the lead to test it and it seem to work the lead turn on and off every second but when I try with the gear pager motor its does not have enough power to move the motor. well the motor move but very slow so its not able to make a sound when it hit something.gear.jpg


 Is the location above the correct location?







Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Oh is it the yellow chip in the first robot ? so where do I put the darlington chip?

But a black chip with the letters "ULN2803" on it, just like shown in the picture. If you already have the yellow chip in the board, then it needs to be removed and the black chip marked ULN2803 should be placed back in, oriented in the manner shown in the picture from the link above.

The yellow chip is a resistor array.

Also though, be aware that the darlinton ULN2803 cannot power servos. That's what the yellow transistor chip is for. On the default 28x project board, it's either servo OR geared pager.

someone correct me if i'm wrong ...

what kind of darlington chip? I don't know about this. Is there many type or its just darlington?

i was confused as well by the way the darlington works. i thought that if i just plugged my pager motor to an output and a ground, it would work, right? wrong. like my hero robologist explained to me, the gm10s need to be driven by the darlington chip (or some other transistor pair, but save yourself some headaches and just use the chip.

And also, all motors must be driven via the outpins.

The darlington doesn't just boost the outpin's signal, however. It works by taking the V1/V2, running it through the motor, and using the outpin high as ground. (counter-intuitive, i know).

So to hook it up:

1. insert the darlington chip

2.  plug one gm10 lead into the V1/v2 (the middle output pin)

3. plug the other gm10 lead into the outpin of your choice (0-3)

4. set the outpin to HIGH

5. do a happy dance.

There are posts elsewhere that suggest using the Darlington driver pins, as Ant stated. Your picture shows a connection to a pin usually used as an input, so would not be good as a driver. One pager motor wire should go to one of the Darlington pins towards the opposite corner, any pin 0 to 3. From this picture, they are the ones in tan color, corresponding to the letter F. The other pager motor lead should be connected to either a V1 or V2 pin (with V1 and V2 jumpered) as shown in red and blue further down that page.

Then write your code 

   high 0  

(or whatever pin was used) to make the motor start turning.


I think the problem may be that you are trying to have the Picaxe drive the motor directly, while the Picaxe will be able to drive an LED (about 20ma, but still best to use the darlinton), it just can't supply enouh current to drive a motor, and if you keep trying to drive it that way, the magic smoke might come out.

I would try moving the motor over to one of the darlinting outputs, or use a transister or relay to drive the motor. Let us know how it goes.