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Send pictures to the round display on your prototype watch over Wi-Fi or Bluetooth.

1. Choose and frame an image

Click or drop an image here

Choose image

Zoom

Drag the image to move it. The circle shows what the 240×240 GC9A01 screen displays.

2. Connect and send

Watch address

Join the watch's Wi-Fi network first. 192.168.4.1 is the ESP32 default access point address.

Swap byte order if colors look wrong

Ready. Choose an image to begin.

Firmware protocol (for your ESP32-S3 code)

Image data: 240×240 pixels, RGB565, 115,200 bytes, high byte first.

Wi-Fi: POST /upload, body is the raw bytes (sent as text/plain to avoid a CORS preflight). Reply 200 with header Access-Control-Allow-Origin: *.

Bluetooth: service 7a1c0001-5d3e-4f6a-9b1c-2e8f4a6d0c01. Control characteristic 7a1c0002-5d3e-4f6a-9b1c-2e8f4a6d0c01 (write): 0x01 + length as 4 bytes little-endian starts an image, 0x02 ends it. Data characteristic 7a1c0003-5d3e-4f6a-9b1c-2e8f4a6d0c01 (write): chunks of up to 100 bytes.