A picstep clone layout, in eagle (attached)

[mk2lehe]

Finally built and tested my own layout of picstep v4. Maybe someone else might find it useful. The files are in Eagle format. Firmware is found on previous post.

It has a few improvements:

* on board +5V regulation.
* ICSP
* small layout (3x2")

And some 'drawbacks':

* double sided pcb
* smd-components

Feel free asking Q.

Henrik

[RTP_Burnsville]

Looks nice, just a comment - Shouldn't the crystal X1 have a couple small capacitors around 20pf, one to each lead to ground?

[Garfield2]

Originally Posted by RTP_Burnsville Looks nice, just a comment - Shouldn't the crystal X1 have a couple small capacitors around 20pf, one to each lead to ground?

Nah, he's using a 3 pin resonator that has the caps already encased. Probably wouldn't be a bad idea to allow for them in case someone wants to use a standard can XTal and caps.

-A.

[pminmo]

MK2,
Nice layout. The only sugggestions I would make is to delete values and cleanup the silkscreen layer. Add a couple of series 1W zeners in input side of the 3 term regulator so a motor voltage up to the max of the lmd part is usable. (i.e. more than 24V)

[mk2lehe]

Some protection zeners would be nice. Also one might consider putting in TVS on the motor outputs.

I have caps on X1, but they are smd and therefore not visible on top layer.

Thanks,

Henrik

[pminmo]

I wasn't referring to protection zeners. As the circuit stands now with a 7805 regulator, you can't use a motor voltage greater than 35.7V. It looks to me as though the LMD driver is ok without external diode protection.

Garfield2..Alan..mk2lehe,
Are you ok with me putting this version of the board on my website?

[mk2lehe]

Fine with me!

Henrik