OpenRTX for T-TWR Plus VHF OpenEdition

01_in_general.md

• OpenRTX device page: https://openrtx.org/#/hardware/ttwrplus
• Product page: https://www.lilygo.cc/products/t-twr-plus

02_steps.md

Flashing OpenRTX for T-TWR Plus VHF OpenEdition

1. create flashing dongle
2. connect JST connector to T-TWR
3. git clone https://github.com/msalau/rl78flash
4. cd rl78flash
5. make
6. wget https://github.com/OpenRTX/sa8x8-fw/releases/download/v1.3.0/sa8x8-fw-sa868s-vhf.s37
7. ./rl78flash -i /dev/ttyUSB0 -m 3 -a sa8x8-fw-sa868s-vhf.s37 -v
8. Disconnect JST flashing dongle and connect to USB (DO NOT CONNECT BOTH ON SAME TIME!!)
9. mkdir tinyuf2 && cd tinyuf2
10. wget https://github.com/adafruit/tinyuf2/releases/download/0.16.0/tinyuf2-lilygo_ttgo_t_twr_plus-0.16.0.zip
11. unzip tinyuf2-lilygo_ttgo_t_twr_plus-0.16.0.zip
12. wget https://github.com/OpenRTX/OpenRTX/releases/download/v0.3.6/openrtx_ttwrplus_v0.3.6.uf2
13. esptool.py --chip auto write_flash 0x0 combined.bin
14. Put openrtx_ttwrplus_v0.3.6.uf2 from step 8 to TWRBOOT Usb device
15. Power off the radio by holding PWR (Volume +) button for 10 seconds and press the PWR button again to boot OpenRTX.

03_flashing_dongle.md

UART_GND o-------------o T-TWR_RG
UART_VCC o-------------o T-TWR_RV (do not connect when supplying the device over USB!)
UART_RX  o---------+---o T-TWR_RT
UART_TX  o----|<|--/
UART_RTS o----|<|------o T-TWR_RR

|<| - diode.

Both 1N4148 and 1N5817 diodes have been tested and work.

Photo: