AVR + CH592

This page covers the common operations and limits of the ATmega32U4 + CH592 wireless module (AVR + CH592 for short), used by Command65 PE and similar models.

How it works

• The ATmega32U4 handles matrix scanning, USB, and keyboard state.
• The CH592 module handles wireless transport (2.4G and BLE); the AVR drives it over UART with a binary frame protocol.
• Supports USB / 2.4G / BLE connection modes.

Wireless function keys

Key	Function
2.4G	Switch to the 2.4G receiver channel
BLE1 – BLE5	Switch to BLE channel 1–5
PAIR / PAR	Enter pairing mode
CLR	Clear pairing records
RST	Reset the module
TOG	Toggle between USB and the most recent wireless channel
USB	Switch to USB mode
BT	Combo entry for Bluetooth operations (some models)

2.4G pairing tips

• On first use or after clearing pairing, press 2.4G first, then insert the receiver.
• If it still fails, press PAR and retry.

Limits and notes

• AVR + CH592 and DuoChord use different modules and protocols; firmware is not interchangeable.
• Command65 PE and Command65 (Bluefruit/DuoChord) are different PCB/wireless solutions; do not mix firmware.

Troubleshooting

• Cannot connect over 2.4G: see Troubleshooting / Wireless.
• Flashing failures: see Firmware Downloads & Flashing.