New Raspbian with RT kernel, B+ compatible

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

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