Kindle Users Can Now Connect Bluetooth HID Devices via Userspace Bluetooth Host
A new userspace Bluetooth HID host, 'Kindle HID Passthrough,' has been developed for Amazon Kindle e-readers. This project allows users to connect various Bluetooth Human Interface Devices (HIDs) such as gamepads, keyboards, and remotes directly to their Kindle devices. It achieves this by implementing a complete Bluetooth stack in userspace, bypassing the Kindle's native kernel Bluetooth drivers, which are noted for being buggy. The HID reports from connected devices are then forwarded to the Linux input subsystem via /dev/uhid, making them appear as native input devices. This functionality is available for jailbroken Kindles and can be installed either directly from KindleForge or manually. The project supports both Classic Bluetooth (BR/EDR) and Bluetooth Low Energy (BLE) HID profiles, and it includes features like multi-device support, auto-reconnection, and an on-device touchscreen UI (BTManager) for managing devices. 
