The Express Receiver is a homebrew, high performance HF amateur band receiver covering the 160, 80, 40, 30, 20, 17, 15, 12 and 10m bands. In 2018 the original PIC-based Display & Control Boards were replaced with an Arduino Mega. The code for the Arduino Mega is in this repository. See www.ad5gh.com for further information.
The main change with the 2020 update was to add one-way CAT control for the receiver. The one-way CAT control enables WSJT-X to set the receive frequency.