Pic 18f & Geckodrive!

[Bomber-eng]

Hello,.
A few days ago i bought some drivers g203 to test.
I would like to know if anybody have any routines for microchip PIC16F or PIC18F in language C (Compiler CCS) to control these drivers for one motor only.
I would like to receive some routines that have initial aceleration control, inicial speed control, speed control, and inicial aceleration. Or indicate a place that i could find these routines.

I'm just starting to program now these drivers, and i like to start correctly if tehy help.

Thank you for our attention.

Best regards.

Hugo from Brazil.

[jcdammeyer]

Hi Hugo,

I'd suggest you join the E-Leadscrew Yahoo group

http://groups.yahoo.com/group/E-LeadScrew/

There in the files section you will find full source code for a PIC 18F series creating step and direction for an electronic lead screw. It uses a serial port for all motion commands.

Stay tuned and soon I'll post the complete stand alone unit that does threading and taper turning on a lathe equiped with two stepper motors.

John Dammeyer

[cnccrive]

Hello Hugo !

I think that what John suggests you is a good starting point.

I also think that you should better contact GEcKo to ask if they are avalable to give you the schematic diagrams of theyr drive.

Otherwise you have to do a lot of Reverse engineering work !

Good Luck !

Claudio -

[niclatrique]

I already made something like that before with a PIC16F. I had accelaration ramp, decelaration ramp, min and max speed. My next step was to implement RS232. Once I'm back home tonight I'll post the source code. It's not in CCS but in PICC from Hi-Tech.


nic

[Bomber-eng]

Thank you very much for your colaboration.

Hugo.

[jcdammeyer]

Hi Hugo,

Originally Posted by Bomber-eng Thank you very much for your colaboration. Hugo.

If you don't have a subscription it's possible to buy a back issue of www.circuitcellar.com Issue #196 November 2006 which also has my article on the PIC based electronic lead screw. Source code is also available from that site. The article explains how the stepper code works.

John Dammeyer

[niclatrique]

Here is the C file I was talking about. I made a mistake, I wasn't planning to implement RS232 but I2C.

I hope you'll be able to do something with this. It's not complete and I cannot provide any warranty on this code.

Nic

[cnccrive]

Sorry Hugo...

I mistakenly supposed you were looking to use the microprocessor inside the GeCko to perform the profiles calculation routines....

Sorry...

[MaXx]

hello

i need information to drive my gecko with a 18f too

for the DIR INPUT : 0 or 5v, ok ?
for the STEP INPUT ? with the PWM ?

Which frequency ? (motor speed ?)
Which duty cycle ?


do you have picture of dir/step signal output at // port of PC ?

[jcdammeyer]

Hi,

Originally Posted by MaXx hello i need information to drive my gecko with a 18f too for the DIR INPUT : 0 or 5v, ok ? for the STEP INPUT ? with the PWM ? Which frequency ? (motor speed ?) Which duty cycle ? do you have picture of dir/step signal output at // port of PC ?

I don't have a GECKO so I can't tell you anything any better than the GECKO user manual.

The direction input is 0 or 5V for direction control. That's pretty easy. Stepping pulses are not PWM. They need to be a pulse of about 5uS or so for each step. If you want to run the motor at 1000 steps per second then you are producing a pulse every millisecond that is at least about 5 uS long. If you are running 100 steps per second then it's a 5uS pulse every 10mS.

The GECKO manual will tell you if you have to sink current through the opto input or source current into the opto input.

Have fun!

John Dammeyer

[MaXx]

cool !

5v for the step too ?


thx

[jcdammeyer]

Hi,

Originally Posted by MaXx cool ! 5v for the step too ? thx

Yes. Depending on which Gecko you have they have a terminal marked common. Contrary to logic this was often a common 5V rather than common as in common ground. That's why you have to read the manual carefully.

Also check in on the Yahoo Gecko group or

http://groups.yahoo.com/group/DIY-CNC/

or

http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/

Someone there can assist you with how to wire a Gecko.

Since the Gecko's were designed to be driven directly from a PC parallel port, I think the ports pull the Gecko inputs to ground sinking current through the opto isolator. But don't quote me on that. The manual or the Gecko support can better answer those questions

John Dammeyer