09-15-2020, 10:55 PM
Well, I see a potential problem. Did you cut the jumper at JB0, and add a jumper at JB1?
By default Rx and Tx are connected together and the routine that sends a byte falls into code that waits on the byte to be received after transmitted (echo'd), and there is a 50ms time out period that can go by if the byte is not received. With Rx and Tx tied together the code just falls through and exits because the byte is instantly available. So, if you are trying to use separate Rx and Tx lines then that would result in exactly what you are seeing. It looks like I need to make another flag bit for handling whether the Rx and Tx are tied together or split. I guess everyone so far that has been using the serial ports in their default half-duplex setup.
if you did not split the lines, then that would mean that you don't have the proper pull-up on the serial port line.
By default Rx and Tx are connected together and the routine that sends a byte falls into code that waits on the byte to be received after transmitted (echo'd), and there is a 50ms time out period that can go by if the byte is not received. With Rx and Tx tied together the code just falls through and exits because the byte is instantly available. So, if you are trying to use separate Rx and Tx lines then that would result in exactly what you are seeing. It looks like I need to make another flag bit for handling whether the Rx and Tx are tied together or split. I guess everyone so far that has been using the serial ports in their default half-duplex setup.
if you did not split the lines, then that would mean that you don't have the proper pull-up on the serial port line.