Ianb007
Junior Member level 1
I am using 2x PIC18f4431's. The one PIC reads PORTB and then sends it via USART (TX). The other PIC then receives the USART signal via the RX pin and then outputs it to its PORTB. I nowhave the problem that the first PIC that reads its PORT B, when displayed on an oscilloscope, shows a light flickering of a couple pins being "on" while they have nothing connected to them or are in the "off" position. On and off meaning, a 5V applied to a pin and 0V/nothing respectively. I have tried putting 1K and 10k pull down resistors of PORTB, but that doesn't seem to help. Even if I have only the Sending pic connected to power and read the PORT and output it via USART, the USART signal seems to at have a flickering bit between the clearly "on" bits. It looks like the pic is sometimes reading a pin to be on when it is off. I am using a baud rate of 9.615kHz. Any known reason or solution?