Monday, February 05, 2007
Dual Darlingtons operational on the new Tommelise controller board...
All that's left to do is put the power transistor that controls the heated extruder barrel and a bunch of two pole connectors to collect the sensor interrupts for limits and shaft encoders.
The 4610 also lets you do direct USB comms instead of having to have a MAX232 comms board to convert PIC serial comms into something your PC can understand. I haven't got around to making that work yet, though.
Because Adrian, Vik and the rest of the conventional RepRap team had pretty much already got their token ring with four controller boards attached approach working I decided that RepRap would be better served if I tried to do some higher risk developments that could, if successful, be used in the next generation RepRap. That's why I'm using shaft encoder feedback gearmotors instead of steppers and a single board, big PIC approach to control.
I think that will be the approach I take with my RepStrap effort, but probably not a PIC.
I'm also curious to know what you program in and if you have your subroutines based on interrupts/hardcoded order or a full-fledged RTOS.
Steppers were already being done by everybody else, so I decided to see if I could get shaft encoded gear motors to work. They're potentially a lot cheaper than steppers and are energetically a lot more efficient. You get much more bang for your buck.
Because you're not using so much power the controller boards are easier and cheaper to build, though the coding is considerably more complicated.
"I'm also curious to know what you program in and if you have your subroutines based on interrupts/hardcoded order or a full-fledged RTOS."
I'm using the Oshonsoft IDE with a BASIC compiler. It's cheap, reliable and Vlad takes quality control very personally.
I'm doing interrupt programming.
Links to this post: