After starting this project, I bought some (random) stuff and tried small things. Finally I tried running an unipolair stepper on the LPT, with an ULN2803 interface. The stepper was running on 12V. I learned that speed is everything. With VB6, windows 98/2000 and some kind of third party com-driver (UserPort.exe), I never could run this stepper fast enough, especially not with the required resolution! Maximum speed was around 15 [RPM] (100 [PPS]), while the target should be around 10K [PPS].
So I decied to stop using (my favorite programming language) VB6 for this ussage. Now I had two options:
While learning a new language was also not too bad (VB6 was getting old all ready), I decided to 'learn' how to write a uC. This will have the big advantage of getting rid of timing issue's on the pc. Now the uC only needs some position information from the pc (like G-Code) and will do the timing very accurate.
Well, this was working, but it's still a long way to programm a complete CNC-controller in assembly code... I gave up this uC project and was looking for a more simple alternative. Actualy there were 3 options:
- Download some nice DIY PIC/USB projects on the internet.
- Buy a Parallax kit, with tons of information.
- Buy a Arduino kit, with tons of information.
Mainly because of the slow progress, I quite this 'multi purpose machine' and started to rebuild the BF16 machine.