Yes on the PIC RX Pin.Hi D,
When you say receiver I do you mean the PIC RX PIN and program?
If the RX has received a mid sentence transmission, and is 'in error' when the next sentence arrives from, are you saying it won't 'see' it? There is quite a gap between sentences.
Hi D,Yes on the PIC RX Pin.
I don't see a gap in sentences so you are going to have to point it out so I can clarify. Do you know how UART works with start/stop bits and the timing? Because if you don't then my explanation won't make sense. There is no magical way for a UART receiver to distinguish between a data bit and the start/stop bits in a transmission that it has jumped into the middle of. It relies on timing to do this which it doesn't have until there is a sufficiently long lull in transmitted messages where nothing is happening.
This, here. is the problem. If the GPS fires off 7 NMEA sentences or BASE continually fires sentences with no delay in between the messages, the MCU will never be able to pick up the $ symbol, or the start bits, or the stop bits,since it will be jumbled in with everything else.I think I understand how the UART bits work, but if I'm not mistaken, the program rejects false sentences, then waits for the next '$' which is the start of both types of sentence.
Hi J,Would it be better to use a PIC with two hw UARTs, one for GPS, one for BASE.
Maybe even one sw, one hw UART.
Hi D,This, here. is the problem. If the GPS fires off 7 NMEA sentences or BASE continually fires sentences with no delay in between the messages, the MCU will never be able to pick up the $ symbol, or the start bits, or the stop bits,since it will be jumbled in with everything else.
Picking out a random section in the middle of that previous paragraph with those rules looks like this:
Hi N,The image you gave is a PCB. It will be much easier for us if you give a circuit.
For RS232 or variations communication, I recommend this circuit. It can only connect an MCU with 2 secondary(slave) MCUs. For the use of 4 secondary(slave) MCUs it needs to be edited.
Hi D,What was the problem?
Hi U,you could also do this with two AND gates, an inverter, and an OR gate. CS2 goes to the inverter and one of the AND gates. The inverter output goes to the other AND gate. the two other inputs on the AND gates are your two serial inputs. the outputs of the AND gates go into the OR gate. the OR gate output is the switch common.