@trublu89
I was facing the same problem and solved it by utilizing a ESP32 in between the Duet3D and the PanelDue, a serial port splitter, so to say.
If that's what you're looking for, head over to Github. There you'll find a description of the project and the firmware source code.
Using a ESP32 seems a bit overdrawn but eventually, you can do so much more (i.e. controlling it via Bluetooth or WiFi - or make use of the additional port pins to address servos or relais) in case you need it.

@JoergS5
Thanks.

@trublu89
I was facing the same problem and solved it by utilizing a ESP32 in between the Duet3D and the PanelDue, a serial port splitter, so to say.
If that's what you're looking for, head over to Github. There you'll find a description of the project and the firmware source code.
Using a ESP32 seems a bit overdrawn but eventually, you can do so much more (i.e. controlling it via Bluetooth or WiFi - or make use of the additional port pins to address servos or relais) in case you need it.