Trying to communicate with a Noritake VFD via an Asynchronous serial interface.
A modified SoftwareSerial example communicates as expected with both the hardware
Serial port and SoftwareSerial port when the USB cable is connected to the UNO R3.
External power is supplied via the DC connector. See attached sketch.
When I remove the USB cable and reset the UNO, the external display goes blank.
Reinserting the USB cable and resetting, the code works and displays on both ports
just fine. :
softserial_test.ino (619 Bytes)