R53 flasher

Firmware for the R53 Shift Light C3 board and K-line + CAN board, straight from the browser.

1

Board

Plug the board into the computer with a USB-C data cable and press Connect. The page reads the chip and works out which build it takes.

2

Firmware

3

Flash

Pick a board and a build first.

Which board

R53 Shift Light C3 board. The shift light as it ships: a 54 × 58 mm board with an ESP32-C3 SuperMini soldered in the middle, USB-C at the top. Plug the cable into the SuperMini. A bare SuperMini on the bench takes the same build.

R53 Shift Light K-line + CAN board. Rev C, with a Seeed XIAO ESP32-S3 soldered flat, USB-C over the top edge. Plug the cable into the XIAO, with the 12 V disconnected: power it from USB or 12 V, never both.

The page reads the chip, picks the build itself, and tells you which build the board is already running. Flash it on the bench, disconnected from the car.

After flashing

  1. The board restarts on its own. Away from the car, the status LED blinks once a second: blue on the C3 board's SuperMini, orange on the K-line + CAN board's XIAO. That's "no CAN", which is what it should say on the bench.
  2. Open the app and connect: the Android app, or logs.geekopolis.com/shiftlight in Chrome (Bluefy on an iPhone). There's no pairing and no PIN.
  3. After a fresh install it runs the default thresholds and colours. Set yours and press Save. An update keeps what was saved.

If it won't connect

  • Use a USB data cable. A lot of USB-C cables are charge-only and the board never shows up.
  • Close anything else holding the port: a serial monitor, PlatformIO, the Arduino IDE, another flasher tab.
  • Force the bootloader: hold BOOT, tap RST, let go of BOOT, then press Connect again. Plugging the cable in while holding BOOT does the same. On the C3 board both buttons are on the SuperMini, next to the USB-C; on the XIAO they are the two tiny ones marked B and R.
  • No driver needed. Both boards use the chip's own USB. In the port list it's usually "USB JTAG/serial debug unit" or "USB Serial Device".
  • Chrome and Edge on a computer can do this. Firefox and Safari can't, and neither can a phone.

Source

The firmware is on GitHub: github.com/MrBlahhhh/esp32-shift-light-R53-mini. Each build links the commit it was built from.

The shift light itself, the housing and the assembled version: ryansdesigns.geekopolis.com/shiftlight.

Pick the board

Only do this if the automatic check got it wrong or couldn't run. The page still checks the chip and its flash before writing anything.

Flash

Serial log