Reprap Electronics build
I ran out of time this weekend to get anything done on the MP3 shield or the MLMC projects. I did however manage to find time to solder up the electronics for my reprap I'm building. After a couple of hitches I also got the firmware on and up and running.I had to download the latest from SVN else I got a clash between the stepper-motor drivers and the servo motor drivers in the firmware for the extruder.
I built the mother board to use a standard PC power connector even though I'm building a reprap. It just seemed silly to power this PCB via USB and then rig the power-supply to power all the other boards. I temporarily used the USB 5V to power the PCB via a pin on the JTAG connector during programming the firmware. Before the firmware on the mother board was programmed the PC PSU wouldn't fire up so I needed a temporary power supply.
I managed to test the extruder board with some test software I found at http://objects.reprap.org/wiki/Microcontroller_Firmware_Hints#Driving_Steppers_with_the_Extruder_Controller_V2.2_.28Arduino_inside....29. But I haven't managed to get it working through the mendel firmware via the host software yet. The thermistor was working so I know the RS485 link is functioning properly. Probably just a configuration.h option I've over looked.
It took a couple of hours to get the three boards all soldered up and tested. I'll post more when I have more done. I'll probably be focusing on the mechanical side of building the Cartesian robot for now so not much electronics left to do, although I still have the firmware to sort through...
[EDIT] It turns out that I had overlooked the I2C connection between the motherboard and the extruder board. I should really have read the instruction.