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Purpose:
- For remote control (RC) pilots who want to see what the values being sent by their transmitter (handset) are.
- ExpressLRS (ELRS) is a new RC protocol that is becoming the dominant control protocol in the hobby.
- To bring-up (build, fix, modify) flight controllers and other related hardware, its useful to have something that can see actual values in realtime.
- ELRS uses the concept of 'binding' (roughly similar to bluetooth) to link stations; to view an ELRS transmitter stream, you must be using the same 'binding phrase' as the transmitter.
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Demo video: https://github.com/sercona/rc-elrs-live-channel-display/raw/main/images/elrs-controller-demo1.mp4
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Based on some demo code from the expresslrs project
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Hardware needed:
- ESP8266 (eg, wemos d1 mini)
- elrs serial receiver (as normally used in a quadcopter, etc)
- SPI TFT display ST7735 (https://www.amazon.com/gp/product/B0C2HNVSWV/)
- 3d printed case
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Software:
- Import the code as you normally would with the arduino IDE
- Flash your esp8266 over its usb serial port. IMPORTANT: remove the elrs receiver when you serial-flash your ESP chip.
- Once flash is done, the elrs receiver module can now be plugged in; with its 'tx' pin (this is the data OUT from the elrs module) connected to the 'rx' pin on the only serial uart of the ESP8266.
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Connections:
- Only 3 wires are needed for elrs listening; the data wire (to the RX gpio of the ESP), and 5v power and ground.
- Power the ESP chip, tft display and elrs module from an external 5v supply.
- If you need to reflash the ESP, remember to remove the elrs (or put a switch on the single data line) before you flash and reconnect after flash is done.
- Wiring gpio pins can be found in src/esp_tft_elrs_decoder.h
- TFT pins on wemos d1 mini: (D4=SPI_CS, D5=SPI_CLK, D6=SPI_MISO, D7=SPI_MOSI, D8=SPI_CS)
- TFT will need backlight; wire that to 5v. RESET wire on tft goes to RESET on ESP chip. Note, TFT vcc is 3.3v not 5v!
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3D print STL files in the stl folder
