Hi mark love what you doing with this project it seems a fantastic option to advanced 3D printing couple of quick questions if you don't mind as I'm very interested in acquiring your panda bored to build a upgraded Delta FL son Q 5
a) first question have you seen the REPRAP firmware that people are using to access DWC https://github.com/gloomyandy/RepRapFirmware Unsure if you think this is interesting but it seems to have some advantages over Marlin and could work really well to bring more users/sales to your RPI 3D controller approach, let me know what you think ?
b) second question is over closed loop stepper motors is there a way they can be used with the Panda controller board as again it could be another way you could help advance the field of 3D printing to provide very much higher accuracy and control than many competitors approaches. not to mention lower power/switching needs on the controller PCB/hat itself ? https://www.biqu.equipment/products/bigtreetech-s42a-42-stepper-motor-closed-loop-driver-board-with-oled-display