Does Pixxi display modules support RS232?

No. Pixxi display modules do not directly support RS232. However, you can use MOTG-RS232 or similar modules to connect a Pixxi display via RS232.

To connect a MOTG-RS232 to a Pixxi display, you can use a MOTG-Breadtooth and a gen4-Breakout.

Using a MOTG-RS232 will require the only COM port of the Pixxi module which is also used in programming the display and a GPIO pin. Therefore, the MOTG-RS232 needs to be disconnected before uploading a project to the display module.