Bumps

> BeagleBone Universal Multi Pololu Steppers

BeagleBone Black cape for [BeagleG][beagleg-url]; using 5 stepper driver modules from Pololu.

Bumps is an board to work together with [BeagleG][beagleg-url], a fast GCode system for CNC/3D printers and one of the first making use of the PRU of the Beaglebone Black for extremely fast step generation.

Find the current version from June 2015 [shared on OshPark][osh-bumps1]. Or use the [Gerber files](./gerbers/bumps-gerbers.zip) directly.

### Version History

• Version 0.1 March 2014 ; 5 Stepper drivers, 2 Power PWMs, 2 small PWM, 2 aux outputs.
• Version 0.2 June 2015; small revision of otherwise great first board (fix a missing pullup and wrong solder-mask at one place).

### Current work Work in progress on 0.3 hardware update.

Version 0.3 is work in progress with some changed FETs and other little changes (see illustration below) but also there is a bigger change (in branch drv8825-direct) work in progress to directly use the drv8825 drivers without Pololu modules.

Features

• Simple, mostly passive board with cheap components.

• Single supply; no separate 5V needed:

  • 5V switching supply to power the BeagleBone from motor voltage (12-36V).
  • Local 3.3V power supply to not put any strain on BBB 3.3V

• 5 slots for [Pololu-compatible][pololu-url] stepper driver boards.
• 1 Emergency switch input, directly wired to hardware-reset stepper drivers.
• 2 high power PWM (Motor voltage, ~20A)
• 2 Open Collector PWM for smaller loads (Up to 20V, ~2A)
• 2 Open Collector Auxilliary Outputs (Up to 20V, ~2A)
• 3 endswitch inputs.
• 3 temperature sensor inputs.

The following illustrations represent the current work in progress:

![Schematic][schem] ![Board][board]

In real life, the March 2014 version (essentially identical to the June 2015 version):

![Assembled][assembled]

• Board fabbed by http://oshpark.com/

• Solder paste dispensed with http://github.com/jerkey 's 3D printer, using

  a program to translate a KiCAD file to GCode (hzeller/rpt2paste ) .. the whole thing made it to Hackaday: http://hackaday.com/2014/04/02/dispensing-solder-paste-with-a-3d-printer/

• Assembled using a self-made vacuum tweezer

  https://plus.google.com/u/0/+HennerZeller/posts/b3NbB7NzQcM

• Early test of the system http://youtu.be/hIEY9077D64

[beagleg-url]: hzeller/beagleg [pololu-url]: http://www.pololu.com/product/1182 [schem]: https://github.com/hzeller/bumps/raw/master/img/bumps-schem.png [board]: https://github.com/hzeller/bumps/raw/master/img/bumps-board.png [assembled]: https://github.com/hzeller/bumps/raw/master/img/bumps-connect.jpg [osh-bumps1]: https://oshpark.com/shared_projects/zIXfRqDE