DIY Multiple Connection Watchman Dongle for SteamVR
FlowingDongle is a very simple dongle for SteamVR that can connect four devices simultaneously with a built-in nrf52840 module and a USB hub.
Includes PCB data created in kicad6 and 3D model data of the case. The main components are made of the following.
| components | |
|---|---|
| USB 2.0 Hub Controller | FE1.1s |
| nrf52840 module | MS88SF2 |
BOM can be viewed here. The PCB design and schematic is minimal and not perfect, although stable operation has been confirmed.
By writing the four hex files via SWD using a device such as Jlink, it can be used immediately as a Watchman Dongle. Firmware comes from the following locations.
| name | place | |
|---|---|---|
| Bootloader | nrf52840_xxaa_debug.hex | nRF5_SDK_17.1.0_ddde560\examples\dfu\open_bootloader\pca10056_usb_debug\armgcc |
| MBR | mbr_nrf52_2.4.1_mbr.hex | nRF5_SDK_17.1.0_ddde560\components\softdevice\mbr\hex |
| SoftDevice | s140_nrf52_6.1.1_softdevice.bin | C:\Program Files (x86)\Steam\steamapps\common\SteamVR\drivers\indexhmd\resources\firmware\radio\gd_1558748372_dfu |
| Application | temp_app_stamped.bin | C:\Program Files (x86)\Steam\steamapps\common\SteamVR\drivers\indexhmd\resources\firmware\radio\gd_1558748372_dfu |
Install Make for Windows and Arm Embedded Toolchain (gcc-arm-none-eabi-9-2020-q2-update-win32.exe) and build with the following command.
cd Desktop\nRF5_SDK_17.1.0_ddde560\examples\dfu\open_bootloader\pca10056_usb_debug\armgcc
make
Open temp_app_stamped.bin with a hex editor and edit the following items.
| adress | before | after | effect |
|---|---|---|---|
| 0x1839D | 1 | 9 | disable index audio device |
| 0x162E0 | Valve VR Radio | any string you like | rename USB device |
Convert firmware using srec_cat_exe.
cd C:\Users\marim\Desktop\Dongle\gd_1558748372_dfu
srec_cat.exe s140_nrf52_6.1.1_softdevice.bin -Binary -offset 0x1000 -o s140_nrf52_6.1.1_softdevice.hex -Intel
srec_cat.exe temp_app_stamped.bin -Binary -offset 0x26000 -o temp_app_stamped.hex -Intel
The license applies to hardware data only.