Can I get a bit of advice? (Simple stepper project)

[dougy83]

Sorry, I forgot you're using the MCP. The pin 17 charge pump connection mentioned above is on the D25 computer/printer connecter or pin 8 of the P computer/printer connector.

There's also a Auto/Manual pin on the MCP - pin 13; try connecting this to 5V or ground to see if your current circuit works. You may find that the charge pump connection is still required in manual mode.

If you want to check if your circuit outputs are oscillating, you could connect a piezo transducer (or a speaker inline with a resistor) between 5V and the output of your circuit - the transducer will emit a tone whenever the axis is to be stepped.

 

[dougy83]

So, the charge pump connection needs to receive a pulse.
I don't see a connection on the M Ctrl connector, just on the P connector.
So I should use the M Ctrl connector, and add a connection to pin 17 of the P connector?
I do have extra 4093 ICs, but I wouldn't know hot to use one to generate a (10k?) pulse stream.

To get a 10kHz pulse from the 4093, see attached image. 3 of the 4 gates are unused and have their inputs tied to 5V. If you don't have 3 x 10k resistors left, just use 1, the frequency will be about 7kHz.

EDIT: -- there's an error in the circuit, pin 12 should be connected to pin 13.