In the cp2102 datasheet, they mention :
The on-chip EEPROM may be used to customize the USB Vendor ID, Product ID, Product Description String, Power Descriptor, Device Release Number, and Device Serial Number as desired for OEM applications.
Could it be that they programmed something in there that mess with estlcam ? I don’t know a lot about these chips and what can be done with them beside USB to UART…
The ability to program the USB vendor information can be handy for 3D printers. If you put the right info there then Windows recognizes it as a 3D printer and does slicing and printing natively.
Yeah I know that, but what I mean is : Can it be used to stop the chip from talking to some software ? Is it all the eeprom on the cp2102 can do ? Because it seem weird that it would allow marlin to talk to a bunch of printer software, but not allow something like Estlcam to talk to the 2560. I checked all the pins on that board and unless I missed something, its pretty mutch a mega2560/ramps board rolled into one, all the pins seem to match and once I replaced the cp2102 with a simple FTDI board Estlcam started talking to the 2560 like it was an old buddy. I pluged in some stepper, drivers and switch just for fun and it all work with Estlcam using the estlcam firmware (using ramps programming options).
Basically the only thing I did was cut the usb data traces before the chip and the tx0 rx0 traces after it (effectively removing it) and soldered a FTDI board on those traces (added a resistor to from the FTDI DTR pin to reset on the 2560 so I can program the 2560 without having to press reset manually) and now everything is happily chugging allong. So the cp2102 is confirmed as the culprit, but looking around on the web I can’t find any reason WHY it was the problem !