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SiK - Firmware for SiLabs Si1000 ISM radios

Why did I need my own fork?

My idea was, to use pairs of the 3DR radios as serial links between a Colorado Time Systems (CTS) System 6 (timing system for swimming) and the other pieces of the puzzle. This system kept the Baud rates rather low at 9600. But it uses somewhat strange parity setups for todays practice:-(

From all my internet reseach, I found that it uses (I'll have to confirm that!):

  • 9600 8-O(dd)-1 for the communication with the meet computer.
  • 9600 8-E(ven)-1 one way to talk to the score board.

The current code deals with the parity bits on both wired segments but leaves the RF segment to just transmit 8-bits and do it's own error corrections. I know, that's not completely correct, but I hope, this will be good enough?!

  • Today, most connections don't use the extra parity bits. 8N1 is the most common transmission scheme and the only one originally supported by this firmware.
  • The cables will be much shorter and not as much in the hostile pool environment.
  • It still has to be tested;-)

Now back to the original;-)

For user documentation please see this site:

SiK is a collection of firmware and tools for radios based on the cheap, versatile SiLabs Si1000 SoC.

Currently, it supports the following boards:

  • HopeRF HM-TRP
  • HopeRF RF50-DEMO

Adding support for additional boards should not be difficult.

Currently the firmware components include:

  • A bootloader with support for firmware upgrades over the serial interface.
  • Radio firmware with support for parsing AT commands, storing parameters and FHSS/TDM functionality

See the user documentation above for a list of current firmware features

What You Will Need

  • A Mac OS X or Linux system for building. Mac users will need the Developer Tools (Xcode) installed.
  • At least two Si1000-based radio devices (just one radio by itself is not very useful).
  • A SiLabs USB debug adapter.
  • SDCC, version 3.1.0 or later.
  • EC2Tools
  • Mono to build and run the GUI firmware updater.
  • Python to run the command-line firmware updater.

Note that at this time, building on Windows systems is not supported. If someone wants to contribute and maintain the necessary pieces that would be wonderful.

Building Things

Type make install in the Firmware directory. If all is well, this will produce a folder called dst containing bootloader and firmware images.

If you want to fine-tune the build process, make help will give you more details.

Building the SiK firmware generates bootloaders and firmware for each of the supported boards. Many boards are available tuned to specific frequencies, but have no way for software on the Si1000 to detect which frequency the board is configured for. In this case, the build will produce different versions of the bootloader for each board. It's important to select the correct bootloader version for your board if this is the case.

Flashing and Uploading

The SiLabs debug adapter can be used to flash both the bootloader and the firmware. Alternatively, once the bootloader has been flashed the updater application can be used to update the firmware (it's faster than flashing, too).

The Firmware/tools/ec2upload script can be used to flash either a bootloader or firmware to an attached board with the SiLabs USB debug adapter. Further details on the connections required to flash a specific board should be found in the Firmware/include/board_*.h header for the board in question.

To use the updater application, open the SiKUploader/SikUploader.sln Mono solution file, build and run the application. Select the serial port connected to your radio and the appropriate firmware .hex file for the firmware you wish to uploader. You will need to get the board into the bootloader; how you do this varies from board to board, but it will normally involve either holding down a button or pulling a pin high or low when the board is reset or powered on.

For the supported boards:

  • HM-TRP: hold the CONFIG pin low when applying power to the board.
  • RF50-DEMO: hold the ENTER button down and press RST.

The uploader application contains a bidirectional serial console that can be used for interacting with the radio firmware.

As an alternative to the Mono uploader, there is a Python-based command-line upload tool in Firmware/tools/

Supporting New Boards

Take a look at Firmware/include/board_*.h for the details of what board support entails. It will help to have a schematic for your board, and in the worst case, you may need to experiment a little to determine a suitable value for EZRADIOPRO_OSC_CAP_VALUE. To set the frequency codes for your board, edit the corresponding Firmware/include/rules_*.mk file.


SiLabs have an extensive collection of documentation, application notes and sample code available online. Start at the Si1000 product page

Reporting Problems

Please use the GitHub issues link at the top of the project page to report any problems with, or to make suggestions about SiK. I encourage you to fork the project and make whatever use you may of it.

What does SiK mean?

It should really be Sik, since 'K' is the SI abbreviation for Kelvin, and what I meant was 'k', i.e. 1000. Someday I might change it.


Tools and firmware for the Si1000







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