picaxe 08m newbie

[AM1987]

Hi,

I have just recently purchased a picaxe 08m kit as I was hoping to use it to control the dc motor on a radio controlled car which i tore apart.

I thought it was best to use relays so i could run the picaxe chip and the motor off different voltage sources and prevent back emf etc from affecting the chip.
I wired up 2 5v spdt relays which (when connected to battery sources) work very well at controlling the motor (i dont need to control speed i just needed to control direction and stop it)

unfortunately, it seems when i connect a pin of the picaxe which is set to high and the 0V pin the relay does not activate. If i connect the V+ and V0 pins straight from the battery it works fine.

I measured the voltages across the different pin combinations and it was the same but for some reason the picaxe chip does not activate my relay.


Giving up on my initial idea of relays i thought i would just connect the picaxe straight to my motor, but again, for some reason the picaxe output pins would not run the motor at all. ( i have tested all pins and outputs and programmes with an LED and all seems to be working)

any insights as to why this is not working or how to make it work would really be much appreciated.

Thanks in advance

Ani

 

[BeanieBots]

STOP.
You are going to destroy the PICAXE if you haven't already.

The PICAXE outputs are only capable of supplying about 20mA which is not enough to drive your motors and (it would appear) not enough for the relay.
Trying to get more current is likely to destroy it.
Have a look in the interfacing manual where you will find a circuit which uses a transistor to drive a relay (or motor) from a PICAXE.