Rohbot's Year of Making Things

How to Flash a Sonde

Catch a Sonde #

Go out and track down a Radiosonde that's been launched by the BOM. It might be helpful to check out auto_rx project

Crack it open #

  1. Using a small flat head screw driver, lever it under the front clip until it pops off
    front clip
  2. Removing the rear clip is a little trickier. Try to push the clips white plastic bit
    rear clip
    Once you get the clips off it good to cut them off with some sidecutters, so it doesn't get snagged

Compiling the RS41HUP firmare #

  1. Follow the instructions on RS41HUP Readme
    I managed to compile it using Windows Sub System for Linux but your mileage may vary
    For those members of the Melbourne Raspberry Pi Hackers looking to flash a sonde with our call sign here is the firmware I prepared eariler..

Flashing Firmware to the Sonde #

  1. Connect the ST-LINK to the RS41 with jumper wires (this is the configuration I used)
Programer cable connections:
RS41 ----- ST-LINK
===================
Pin 1 ----- GND (Pin 5)
Pin 5 ----- 5.0V (Pin 9)
Pin 8 ----- SWCLK (Pin 2)
Pin 9 ----- SWDIO (Pin 4)

Vaisala RS41 Expansion Connector Pinout #

Based on work by DF8OE
Viewed into port from outside

----------|     |----------
|  9    7    5    3    1  |
|                         |
|  10   8    6    4    2  |
---------------------------
  1. Open up ST-Link Utility
  2. Click Target and then Connect and you should see something like this:
    st-util
  3. If this is the first time flashing the sonde, you will need to disable Read Out Protection
    Click Target, then Option Bytes and make sure Read Out Protection is disabled
    option-bytes
  4. You should now be ready to flash new firmware to the sonde
    Click Target, then Program and Verify and select the RS41HUP.bin you have either compiled or downloaded here
    Hit Start to flash the file to the sonde
    If it works next time you push the power button on the Sonde it should be transmitting on 434.2 MHz

Disclaimer #

This is not the only way to flash the RS41HUP firmware to a RS41 but this is what worked for me
I compiled the firmware using WSL and then flashed the Sonde in Windows 10. I haven't tried using openOCD or stlink