Weve hit a wall UPDATED 06/13/10 06/11/2010
I was hoping to have better news by now but it is what it is. Grbl needed to be modified inorder to get the stepper drivers to dance. There needs to be a moment of pause between the pulse that signals the step and the next pulse....or something. Im not a programing wiz like some. I enjoy it and I tinker with it but thats about it. With that said grbl will now accept single lines of g-code through cutecom and execute them perfectly. Thats great if you want to do a project one line at a time. The problem comes in when a script comes in to send the commands to grbl from a file on the computer. I suspect that the delay I placed in the grbl code is causing some timing issues and tripping up the program when lines of gcode are sent one after another. The result of sending a line of gcode through cutecome looks similar to this.
G1 X5.345 Y4.332
Then you can send another line and it all works like its supposed to. Now when the script does it it comes out looking like this
G1 X5.345 Y4.332
G1 X1.115 Y7.223
Grbl>>G1 X5.345 Y4.332
G1 X2.225 Y7.435
and it stalls. Sometimes the first line is executed. some times its not. Now with the same script and the reprap 1.3 firmware all codes are executed but somethings seem to be different. Normally I would expect G1 X7 to turn 7 times then G1 X5 to turn back 2 turns. At least thats how grbl worked. The reprap FW turns 7, pauses a fraction of a second and turns 5 more in the same direction. Im assuming this is a setting or just a difference in code that can easily be fixed. Ive Emailed the writer of grbl but Im not sure if I did a great job of explaining my problem or if he will be willing to help me out. Well see when he emails me back. As for now Ive come across a couple of other ideas to try and implement and I will try to continue to read through grbl hoping for something to pop out at me.
Ive been emailing back and forth with Simen the programmer of the GRBl code. Were working through the basics now. making sure Ive got all my grounds and playing with settings. Its not looking great at the moment. well my set up is looking fine so far but since it workes with the modified code to a certain point I figured the stepper driver was looking for a a little different signal. well see how it comes out.