PIC #1:

Code:
    TXSTA.5 = 1                     ' TXEN: Transmit Enable bit
    hserout [   "[1]"    ]                             
    while TXSTA.1 = 0               ' Check TRMT: Transmit Shift Register Status bit
    wend
    hserin [ wait("["), STR RecvData\11\"]" ]
    hserout [   "[2]"    ]                             
    while TXSTA.1 = 0               ' Check TRMT: Transmit Shift Register Status bit
    wend
    pauseus 300
    TXSTA.5 = 0                     ' <----- Causes Framing error after last byte !

Mainloop:
    BlinkLED = 1
    BlinkLED = 0
    goto mainloop
end

PIC #2:

Code:
ReceiveInterrupt:
    hserin [ wait("["), STR RecvData\11\"]" ]
    UsartFlag = 1
@ INT_RETURN

Start:
    Pause 200                           ' Let PIC and LCD stabilize

Mainloop:
    LEDblink = 1
    if UsartFlag = 1 then
        TXSTA.5 = 1
        hserout [   "[0]"  ]                            
        while TXSTA.1 = 0              ' Check TRMT bit
        wend
        UsartFlag = 0
        TXSTA.5 = 0
    endif
    LEDblink = 0
    GOTO Mainloop
end

1. PICs can talk back and forth with no errors.

2. PIC #2 can disable transmitter every single time.

3. Framing error as soon as PIC #1 disables transmitter, causing PIC #2 to lock up (no more blink LED on bottom channel).


Name: Framing error e.png Views: 8490 Size: 43.9 KB