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Overview

tip
  • Supported hardware: ESP32-S2, ESP32-S3
  • Firmware is free; buy dev boards on Taobao, Pinduoduo, 1688, etc.

Hardware photo​

  • Example shows a basic adapter; for charge + OTG use a 3-in-1 adapter

Download firmware​

  • Cloud drive: Downloads
  • Path: Developer tools → Android resources → OTG HID firmware → ESP32-S3 or ESP32-S2 — download the .bin for your board
  • Keyboard and non-keyboard builds — some apps detect keyboard HID; the non-keyboard build cannot use Home and similar input APIs
  • Download flash_download_tool.zip for ESP32 to flash firmware

Flash firmware​

  • Same steps as Bluetooth: Flash Bluetooth firmware
  • OTG firmware does not need the Bluetooth MAC — skip that step and flash only
  • S2: hold IO, press RST, release both so the PC detects the board
  • ESP32-S2: hold BOOT, tap RST
  • ESP32-S3: after flashing, plug into the phone's USB OTG port, not the COM port

Authorize and test​

  • First plug-in may show an authorization dialog
  • Check Always use (wording may vary) and confirm
  • System settings → OTG HID settings → Connect OTG — allow any permission prompt
  • Click Test HOME — if you return to the home screen, it works; next step is scripting

Use in scripts​

  • After the steps above and a successful test, write scripts and call API functions