Initial A3979 Stepper Driver Development
A new driver based on the A3979 chip is in development. The A3979 is a tough chip to use since it needs ample and large contiguous copper surface area for heat dissipation. The great aspects of this driver chip is the integrated translator, the power for 2.5 amps per phase, and the ability to set to 1/16 microstepping. This driver requires less peripheral circuitry and may allow me to put three drivers on one board. I am also planning on making a small driver board if another 4th axis, or 4th motor is needed. Another reason this driver chip is used is that the cost is low and I don't need a microcontroller sending out PWM (pulse width modulation) to the vref of other non integrated drivers to get the 1/16 microstepping. The board and schematic will be available for download. I would recommend this project for the advanced level hobbyists.
I'm still in prototype stage with the electronics. The driver design has changed slightly to take advantage of more power to enable a wider variety of stepper motors. The electronics will now be based on the L297 and L6203 combo and will drive bi-polar stepping motors up to a whopping 4 amps per phase. The driver circuit will be designed to drive three axes without the need for a breakout board. That is to say, you will only need one driver board that the parallel port will connect and output to the three motors. Very simple.
The kit will be offered in two forms. the first configuration will be a kit that will require complete assembly (approximately 4 - 5 hours assembly). The second option will offer the electronics assembled.
Stay tuned during this timeframe that I will be developing this kit and I would like to hear any comments that you may have. If there is a specific product or component that you would like to see, or see develop, please provide