Building a Breezedude from scratch - thezenox/breezedude GitHub Wiki

If you want to build it from scratch yourself, here is a short guide. This is not meant to be a easy step-by-step manual and may require some basic knowledge in embedded development, SMD soldering skills and programming.

Getting the PCB

The KiCAD files are included in the repo. Generate gerber files (+BOM/CPL) using a fabrication plugin of your choice. You can choose ordering a naked PCB and source & solder the components yourself or order a SMD pre-assembled PCB. Battery holder, connectors and SMA connector can be soldered by hand.

For private use (within your club and the friends of the other club...) this can be done free of charge. If you plan to sell the boards (commercially) a small licensing fee will help support my work (see LICENSE for details).

Flashing the bootloader

A factory new SAMD21 IC ships without any firmware. For programming, it requires a compatible SWD programmer. The adafruit bootloader is used. A binary of a custom breezedude version is included in this repo (only changed the USB PIDs & descriptor and names of the bootloader flash drive)

Connect SDWIO, SWDCLK, GND and apply battery voltage for flashing. The blue LED should start fading after flashing.

After flashing the bootloader once, the firmware and bootloader can be updated by drag&drop UF2 updates.

Bootloader flashing using a DAPLink as programmer 1.27mm Pinheader as kind of pressfit the SWD socket

ST-Link does not work with SAMD21

For just flashing the bootloader binary an open-ocd compatible CMSIS-DAP is the easiest choice. Install open -ocd according to its documentation (+add to PATH) and run

openocd -f interface/cmsis-dap.cfg -f target/at91samdXX.cfg -c "program bootloader-breezedude-v3.16.0-19-atmel.bin verify reset exit 0x00000000" within the bootloader directory.

output should look like this:

openocd -f interface/cmsis-dap.cfg -f target/at91samdXX.cfg -c "program bootloader-breezedude-v3.16.0-19-atmel.bin verify reset exit 0x00000000"
Open On-Chip Debugger 0.12.0 (2025-07-10) [https://github.com/sysprogs/openocd]
Licensed under GNU GPL v2
libusb1 d52e355daa09f17ce64819122cb067b8a2ee0d4b
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
Warn : DEPRECATED: auto-selecting transport "swd". Use 'transport select swd' to suppress this message.
Info : Using CMSIS-DAPv2 interface with VID:PID=0x0d28:0x0204, serial=00000080003400454e00000e4e574c50a5a5a5a597969908
Info : CMSIS-DAP: SWD supported
Info : CMSIS-DAP: SWO-UART supported
Info : CMSIS-DAP: Atomic commands supported
Info : CMSIS-DAP: Test domain timer supported
Info : CMSIS-DAP: FW Version = 2.1.0
Info : CMSIS-DAP: Serial# = 00000080003400454e00000e4e574c50a5a5a5a597969908
Info : CMSIS-DAP: Interface Initialised (SWD)
Info : SWCLK/TCK = 1 SWDIO/TMS = 1 TDI = 0 TDO = 0 nTRST = 0 nRESET = 1
Info : CMSIS-DAP: Interface ready
Info : clock speed 400 kHz
Info : SWD DPIDR 0x0bc11477
Info : [at91samd.cpu] Cortex-M0+ r0p1 processor detected
Info : [at91samd.cpu] target has 4 breakpoints, 2 watchpoints
Info : [at91samd.cpu] Examination succeed
Info : [at91samd.cpu] starting gdb server on 3333
Info : Listening on port 3333 for gdb connections
[at91samd.cpu] halted due to debug-request, current mode: Thread
xPSR: 0x21000000 pc: 0x00000268 msp: 0x20002de0
** Programming Started **
Info : SAMD MCU: SAMD21G18A (256KB Flash, 32KB RAM)
** Programming Finished **
** Verify Started **
** Verified OK **
** Resetting Target **
shutdown command invoked

Debugging the Code

For Debugging CMSIS-DAP is currently not supported out of the box for SAMD21. ToDo: Custom script for using open-ocd

The following should work (see PIO docs)

• blackmagic
• Atmel ICE
• Segger Jlink

Prepare the housing

Insert the sealing in the cover, drill holes for antenna (M20), sensor cable (M12), pressure valve (M6) and solar cell (12mm) You can use the screws provided or replace them with M3x12 and melt nuts For mounting on the pole add some M5 melting nuts in the back Make a mounting plate according to your needs

Glue the solar cell using some neutral silicon. Mark the polarity as you can not see the labels afterwards. When cured, solder the wires The finished setup could look like this