<- back to downloading and adapting the (Marlin based) firmware for the Anycubic I3 Mega

Using serial console within arduino IDE at 250000 baud

The serial terminal application which is able to handle the non-standard 250000 baudrate, is the one included in the Arduino IDE. However with a workaround.¹⁾

A workaround is the following:

Power cycle the printer and make sure the printer is connected to the PC. Then start the Arduino IDE, configure the correct serial port (Per default this is /dev/ttyUSB0).

From within the Arduino IDE, open the Serial Monitor. You will likely see garbled text:


1. Observe garbled text with a baudrate of 250000 (or alternatively no text at all.)	2. Change the baudrate to 230400	3. Set the baudrate back to 250000

4. After setting the baudrate back to 250000 close the Serial Monitor (But keep the Arduino IDE open). Then set the non-standard baudrate of the serial port via the command line with the python script as shown here and use the given command to set the baudrate to 250000 (In this case for ttyUSB0):

./mysetbaud.py <>/dev/ttyUSB0 250000

5. Reopen the Serial Monitor in the Arduino IDE. Now it you should see normal text:

Output OK, reveals an EEPROM version mismatch…

¹⁾

Without experimenting further, maybe the root cause has to do with the “auto reset on serial connection”, as explained here: the https://playground.arduino.cc/Main/DisablingAutoResetOnSerialConnection/