# ESP32-C6-LCD-1.47 WiFi List Firmware

This workspace contains a custom firmware for the non-touch Waveshare `ESP32-C6-LCD-1.47`.

The firmware does one job:

- boot the board
- turn the LCD backlight on
- scan nearby 2.4 GHz Wi-Fi networks
- display the visible SSIDs as a green list on the screen
- rescan periodically

The active Arduino sketch is:

- [Arduino/examples/LVGL_Arduino/LVGL_Arduino.ino](/Users/drjones/Library/Mobile%20Documents/com~apple~CloudDocs/dev%20shit%20life/4%20way%20handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino/LVGL_Arduino.ino)

## Why This Works On This Device

This firmware is specific to the non-touch `ESP32-C6-LCD-1.47` board because it matches the board's actual LCD wiring and controller assumptions:

- LCD controller: `ST7789`
- LCD size: `172x320`
- SPI LCD pins:
- `MOSI = GPIO6`
- `SCLK = GPIO7`
- `LCD_CS = GPIO14`
- `LCD_DC = GPIO15`
- `LCD_RST = GPIO21`
- `LCD_BL = GPIO22`

Those values match the Waveshare `ESP32-C6-LCD-1.47` documentation and the vendor Arduino template for this exact board.

It is not intended for:

- `ESP32-S3-LCD-1.47`
- `ESP32-S3-Touch-LCD-1.47`
- `ESP32-C6-Touch-LCD-1.47`
- other ST7789 boards with different offsets, reset wiring, or backlight control

## The Important Fixes

The stock demo was close, but not stable enough for this board until a few things were corrected:

- The display flush path was using a large per-refresh stack buffer in `LCD_addWindow()`. That is a bad failure mode on the C6 and can leave the panel black. The firmware now sends pixel data without allocating a useless receive buffer.
- Backlight duty handling was cleaned up so `GPIO22` is driven with the correct full-scale PWM value instead of a fragile hard-coded number.
- The board now boots into a minimal screen path instead of starting the original SD-card and wireless demo logic at the same time.
- The app uses the official C6 template's panel init and geometry, including the `172x320` layout and the vendor offsets already present in `Display_ST7789.h`.

Those fixes are why this firmware works on this unit when the earlier mixed S3/C6 attempts did not.

## Caveats

- This is for the non-touch C6 board only.
- It scans `2.4 GHz` Wi-Fi networks. That is normal for ESP32 Wi-Fi scanning.
- The screen can only show a limited number of SSIDs cleanly at once, so the firmware renders the first visible chunk and rescans periodically.
- Hidden SSIDs are shown as `<hidden>`.
- Network order is whatever the Wi-Fi stack returns for that scan, so entries can move between rescans.
- Long SSIDs wrap on screen.
- The sketch uses Arduino and the bundled offline `lvgl` library from this project.
- The build uses the `huge_app` partition scheme. That is the known-good setup for this workspace.

## Files That Matter

- [Arduino/examples/LVGL_Arduino/LVGL_Arduino.ino](/Users/drjones/Library/Mobile%20Documents/com~apple~CloudDocs/dev%20shit%20life/4%20way%20handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino/LVGL_Arduino.ino)
  Boot flow for the scanner firmware.
- [Arduino/examples/LVGL_Arduino/WiFi_Scanner.cpp](/Users/drjones/Library/Mobile%20Documents/com~apple~CloudDocs/dev%20shit%20life/4%20way%20handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino/WiFi_Scanner.cpp)
  Wi-Fi scan logic and SSID formatting.
- [Arduino/examples/LVGL_Arduino/LVGL_Driver.cpp](/Users/drjones/Library/Mobile%20Documents/com~apple~CloudDocs/dev%20shit%20life/4%20way%20handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino/LVGL_Driver.cpp)
  Green-on-black screen layout and text updates.
- [Arduino/examples/LVGL_Arduino/Display_ST7789.cpp](/Users/drjones/Library/Mobile%20Documents/com~apple~CloudDocs/dev%20shit%20life/4%20way%20handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino/Display_ST7789.cpp)
  Board-specific LCD write path and backlight control.
- [Arduino/examples/LVGL_Arduino/Display_ST7789.h](/Users/drjones/Library/Mobile%20Documents/com~apple~CloudDocs/dev%20shit%20life/4%20way%20handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino/Display_ST7789.h)
  The exact pin map and screen dimensions.

## Known-Good Build And Flash

Compile:

```bash
arduino-cli compile \
  -b 'esp32:esp32:esp32c6:PartitionScheme=huge_app' \
  --build-path /tmp/arduino-build-c6-wifi-list \
  --libraries '/Users/drjones/Library/Mobile Documents/com~apple~CloudDocs/dev shit life/4 way handshake/ESP32-C6-LCD-1.47-Demo/Arduino/libraries' \
  '/Users/drjones/Library/Mobile Documents/com~apple~CloudDocs/dev shit life/4 way handshake/ESP32-C6-LCD-1.47-Demo/Arduino/examples/LVGL_Arduino'
```

Flash:

```bash
arduino-cli upload \
  -p /dev/cu.usbmodem1101 \
  -b 'esp32:esp32:esp32c6:PartitionScheme=huge_app' \
  --input-dir /tmp/arduino-build-c6-wifi-list
```

If your serial port changes, replace `/dev/cu.usbmodem1101` with the current device from `arduino-cli board list`.

## References

- Waveshare product page: https://www.waveshare.com/esp32-c6-lcd-1.47.htm
- Waveshare wiki: https://www.waveshare.com/wiki/ESP32-C6-LCD-1.47