Show HN: I wrote a small lib to turn a USB gamepad into a Bluetooth one

Summary

ESP32-S3 firmware that turns a USB HID gamepad into a Bluetooth LE (BLE) gamepad. Plug a wired controller into the board (USB Host), and the firmware advertises as a BLE gamepad so a phone/tablet/PC can connect to it wirelessly. Hardware Seeed Studio XIAO ESP32S3 (the current PlatformIO target: seeed_xiao_esp32s3 ) (the current PlatformIO target: ) A USB HID gamepad/controller (wired USB) (wired USB) A USB-C OTG adapter (USB-C male → USB-A female), or a powered USB hub + suitable cables (USB-C male → USB-A female), or a + suitable cables Optional: a 3.3V UART adapter for debug logs on pins GPIO12 (TX) / GPIO13 (RX) (see platformio.ini ) Power note: some controllers draw more current than the XIAO can comfortably supply. If your controller doesn’t enumerate or resets, use a powered hub. How to connect it Flashing / development: connect the XIAO ESP32S3 to your computer via USB-C. Runtime (USB Host): connect your USB controller to the XIAO’s USB-C port through an OTG adapter (or powered hub). Pair the BLE device from your phone/tablet/PC like a normal Bluetooth controller. Flashing (PlatformIO) This is a PlatformIO project ( platformio.ini ). The default environment enables USB Host (OTG) and routes debug output to a hardware UART. Build: pio run -e seeed_xiao_esp32s3 Flash: pio run -e seeed_xiao_esp32s3 -t upload Serial monitor (if you use UART): pio device monitor -b 115200 There is also a development environment that disables USB Host and keeps USB CDC enabled (useful for quick flashing/monitoring over the built-in USB serial): Flash (dev): pio run -e seeed_xiao_esp32s3_dev -t upload The project uses a custom partition table referenced by platformio.ini : partitions_4MB.csv Architecture overview At a high level, the firmware runs a USB Host stack to enumerate a connected HID controller, parses the HID reports into a normalized internal GamepadState , then maps that state into BLE HID gamepad reports exposed via the BLE gamepad library. The USB side and BLE side are...