Could more technical data of the J1 be provided which would be needed to program a controler board, such as motor currents and steps per mm?
I still have to get mine, but from what I currently know, I will probably want to change the inbuilt controller board with a Duet or such, since the J1 seems to have a really great hardware (which is why I bought it in the first place) - but it seems it neither has a decent webinterface nor support for custom macros.
Basically all the things you require to set up a standard electronics board for a 3D printer:
pinout for the electrical connectors within the printer from / to the main controller board (motors, fans, sensors, hotends, power supply), ideally with a remark about which type of connector is used. (The best option would be to share all connector pinouts and types since this greatly facilitates searching for errors or creation of custom upgrades - but I understand that you do not want to make it too easy for copycats)
max. rated current for all stepper motors (X, Y, Z, E - M906 settings in Marlin)
steps per mm for all stepper motors (M92 settings in Marlin)
max. permissible accelerations, speeds and speed changes - whatever is defined in Marlin with M201…M205
stepper driver settings (M569 in Marlin - assuming you use TMC drivers this would be min.step pulse, min.step interval, DIR setup time, hold time, Toff)
type of temperature sensors that are used within the hotend / heat bed (or PID settings or a temperature → resistance table for each sensor type in case you use your own custom types. M301 / M304 / M305 settings in Marlin. Since other gcode flavours auch as RRF use different means to tune thermistors, knowing the exact thermistor type would be the best option however)
voltage of heaters in hotend and bed
type or at least supply voltage of fans
type/output logic and supply voltage of filament sensors, endstops and z probe. For the latter, you could actually make additional money by selling an adapter board which drives the sensors built into the bed and offers a standard output signal that can be used by other controller boards since I guess this is some custom thing and not a simple “on/off” switch logic
XY coordinates of z probe points and bed level screws
Depending on how much you would like to open up about the internals of the printer, it would be great if you could provide some further details about the electronics you use:
is the main controller board some kind of standard board with just a customised firmware or is it completely custom?
what are the mechanical dimensions of the controller board?
everything you would be willing to share about the display that might help in understanding how to attach it to another controller board (dimensions, interface type, if it has its own firmware as e.g. the Duet displays have or if it is driven completely by the controller board, communication protocol between display and board etc.). If I understand your technical specs correctly, the display uses an Android OS which means you are required to make the source code public anyway.
In case you use some standard board it would suffice to say “we use controller board XYZ but with our own custom firmware. Please refer to the board manufacturer for details.”
Okay… as soon as you Akismet spam system decides that my answer is not spam, you will be able to see what I ask for (it was flagged as spam when I tried to correct some typos).
and have passed them to our R&D team. As soon as they reply, I’ll update.