New Raspbian with RT kernel, B+ compatible

RT-Tests

This document is not updated, please proceed to docs.emlid.com for latest version!

We have a new image of Raspbian with kernel patched with a real-time patch from Ingo Molnar available for download. It is useful for projects that require stable low latencies – max latency with PREEMPT-RT kernel on Raspberry is around ~70 microseconds (without any overclocking). The image was tested for compatibility with Raspberry Pi Model B and Raspberry Pi Model B+.

The image is not intended for general purpose use but rather for embedded electronics projects.

 

List of changes includes:

  • Added RT_PREEMPT kernel(/boot/kernel-rt.img)
  • Placed kernel source patched with rt-patch in /usr/src/
  • Enabled SPI
  • Enabled I2C
  • Increased I2C speed to 400KHz
  • Installed I2C-tools
  • Installed pigpio (https://github.com/joan2937/pigpio)
  • Installed rpi-serial-console (https://github.com/lurch/rpi-serial-console)
  • Installed socat
  • Installed screen

 

Known issues:

  • Due to the required options some USB keyboards may not work

 

Download link:
Raspbian-SEP-2014-RT-B+.img.tar.bz2

 

Thanks to Egor Fedorov and Jonathan Seawright for their work on compiling the RT kernel.