PICStep Microstepping Controller
Here is a PNG of the driver board. It includes an ICP socket to program the PIC while in-circuit, I/O port to control the driver (Step, Direction, Brake, Mode Bits).
I'm starting to create the PCB layout. Check back soon!
| Attachment | Size |
|---|---|
| picstep_schema_v1_lrg.png | 68.29 KB |
As I was updating the website my package from Digi-Key USA arrived!
It contained 4 x LMD18245's and 2 x L298's. This means I can now move on to testing my firmware with actual devices!
Stay tuned!
| Attachment | Size |
|---|---|
| lmd18245.jpg | 68.21 KB |
Here is my breadboard with a development version of the firmware displaying on a 10 LED bar. I'm testing the interupt routine and the mode switching. I'm pretty much pushing the limits on the I/O of the 16F628, but then again what's the use of all those I/O pins if you never use them!
Currently I've got the design layed out as followed :-
- RA0 - CA0 | Coil A Bit 0
- RA1 - CA1 | Coil A Bit 1
- RA2 - CA2 | Coil A Bit 2
- RA3 - CA3 | Coil A Bit 3
- RA4 - MODE0 | Mode Input Bit 0
- RA5 - MODE1 | Mode Input Bit 1
- RB0 - STEP | Step Input
- RB1 - DIR | Direction Input
- RB2 - CB0 | Coil B Bit 0
- RB3 - CB1 | Coil B Bit 1
- RB4 - CB2 | Coil B Bit 2
- RB5 - CB3 | Coil B Bit 3
- RB6 - CBD | Coil B Direction
- RB7 - CAD | Coil A Direction
This means the RA5/MCLR line is turned internally to high so I can use it as an input. I'm also going to design the PCB with a jumper block/DIP switches to enable ICP via a programming header on board. This will allow me to update the firmware in-circuit incase there are some modification I wish to make after the fact (1/32 stepping maybe :)
| Attachment | Size |
|---|---|
| picstep_devel.jpg | 142.23 KB |
