Help! DIY 4 amp L297/6203 driver

[Kwackers]

Nope.

Connect one pin of the pic to a 3k9, the other to a 19k.

Now connect the other end of the resistors to the top of the VR, the bottom of the VR connects to 0v and the wiper to VRef.

That's it!

[Ross77]

Okay - just one slight change - pull the reset low with a 10k resistor. That will ensure that the L297 is in a reset condition before the PIC starts up.

GP3 can only be used for a digital input, so there's not a lot you can do with it, I'm afraid!

Like so?

Connect one pin of the pic to a 3k9, the other to a 19k.

Now connect the other end of the resistors to the top of the VR, the bottom of the VR connects to 0v and the wiper to VRef.

That's it!

Thanks, think i under stood that better.

Ok so Kwackers option is easy to do and gives me adjustable vref with a fixed idle current at 25% (which could be changed by swapping out the 19 K resistor?) and Tribbles options uses a few more trim pots but means I can easily adjust Vref max, vref hold and the delay time. Correct?

For the trimmers am I looking at quality multiturn (£1 each) or will the cheap low wattage single turn (10p) be ok? would need 9 for 3 axis.

Thanks again. looks like its nearly there :dance:

[tribbles]

Like so?

Yes (from my side ).

Ok so Kwackers option is easy to do and gives me adjustable vref with a fixed idle current at 25% (which could be changed by swapping out the 19 K resistor?) and Tribbles options uses a few more trim pots but means I can easily adjust Vref max, vref hold and the delay time. Correct?

Yes - you could even put an open-ended trim instead of the 19K to make that variable.

For the trimmers am I looking at quality multiturn (£1 each) or will the cheap low wattage single turn (10p) be ok? would need 9 for 3 axis.

I don't see a problem with cheap.

If you were to put all 3 on the same board, you could use a single PIC to control them all - then there'd only be one pair of trimmers for the duration/hold...

[Ross77]

Yes (from my side ).

Hurray at last :heehee:

If you were to put all 3 on the same board, you could use a single PIC to control them all - then there'd only be one pair of trimmers for the duration/hold...

I thought we'd ruled out an all in one board? also wouldnt this also mean the control is global? I was hoping to be able to set up each motor separatly.

So just need to check the type and size of a few components and we should be good to go.

Are there any parts to look out for? I now the polar caps just have to be 50v and the sense resistors 2 watt. Can the caps be any type or is polyester or tantilum required?