I have some specific requirements to communicate with an Arduino Uno that is sporting a CNC Shield.
I must communicate with the arduino directly through the transmit and receive pins (1 and 0).
I cannot use soft serial or other pins.
I must be able to send and receive messages from pins 1 and 0 to an external device like a computer or a serial modem.
I cannot use the USB port at all.
Right now, if I directly interface with pins 1 and 0 and my PC's native COM port, I see garbled text when I send a message from the arduino. I have the PC and the arduino set at 115200 Baud.
For grins, I used the same terminal program (hercules), but connected through the Uno's USB interface and I see the data properly. Again, I cannot use this in my final design, but it at least tells me the arduino is talking.
What am I missing?