Description Brainwave is a low cost controller for Reprap 3D printers derived from the well known Sanguinololu. The primary design goal was lower cost, achieved by providing only the minimum required components for a single extruder printer. It can be used to drive a cartesian or delta style printer.
Features: Small footprint: only 60mm x 79mm!
12V power input
Micro USB connector All connectors at edge of board, vertical or right-angle connectors will fit..
Atmel AT90USB646 microcontroller w/ USB bootloader
1, 2, 16 or 32x microstepping @ up to 800mA
Dual Z-axis connectors
Optional per channel current attenuation
Heated bed support with separate power input (up to 24V @ 15A)
Integrated heater/thermistor/stepper connector for E channel
Instructions Build, buy or borrow a Brainwave
Install Arduino 1.0.2
install the brainwave arduino hardware bundle from github.com/unrepentantgeek/brainwave-arduino into the Arduino hardware directory.
Get Marlin. I am maintaining a branch of Marlin that will compile for brainwave at github.com/unrepentantgeek/Marlin Marlin HEAD has support, but it doesn't always compile cleanly for this board.
Set micro-stepping selector jumpers (D1, D2) per channel. Short both for 32x microstepping. See table on back of board for other configurations. Default: single-step.
Set stepper current reference voltages. I = V / 2.55 Default: 1V == 400mA.
Software configuration Open Arduino, find the Marlin directory and open Marlin.ino.
Select 'Brainwave' from the Board menu. Find the Configuration.h file and change DEFAULT_AXIS_STEPS_PER_UNIT to suit your printer (remember, 32x microsteps!)
Power on the Brainwave and connect the USB cable (note: the brainwave will not power up off USB, you need the 12V supply.)
Hold down the PROGRAM button and press RESET, the STATUS led should pulse.
Press the Upload button in Arduino.
After a reset the brainwave will show up as a CDC ACM serial device (/dev/ttyACM[0..9] on Linux) and be ready to accept commands.
Brandon Bowman wrote up an excellent guide for getting the board working under Windows and MacOS: fabbersuw.blogspot.com/2012/12/if-your-brainwaves-got-no-brains-or.html
Known issues It may take a couple of presses of the RESET button to get the firmware to come up after flashing.
You may need a thermistor or similar 100k resistance present across the bed and extruder thermistor inputs. Otherwise Marlin may go into a deathloop and you'll never even see a serial device. Even if it doesn't fall on it's face it will only sit and complain about too high temp. Marlin may lose/gain steps on the X axis. If so swap X and E to limit the impact. This has not been observed with Sprinter. The issue is being investigated.
Special thanks Julie Atwood