To avoid suspense:  The schematic perfectly matches what HALCOGEN claims are the correct Rx and Tx pins.  If I remove the connection to pin 92 (Rx) it keeps going.  So the blinky board is certainly correct. 

Of course Rx and Tx are relative to which end of the wire you are looking at.  That is Tx on the board connects to Rx on the terminal.  That seems like the most likely explanation.  The usb/serial adapter is labelled from the POV of the terminal.

Anyway...speed test next.

73,

Burns Fisher, WB1FJ

AMSAT(R) Engineering -- Flight Software

On Fri, Feb 2, 2024 at 10:14 AM Burns Fisher (AMSAT) <wb1fj@fisher.cc> wrote:

I put in this code temporarily:

       GPIOEzInit(LED1);
    GPIOEzInit(LED2);
    GPIOEzInit(LED3);
    GPIOSetOn(LED1);
    GPIOSetOff(LED2);
    sciSetBaudrate(scilinREG, 110);
    sciSetBaudrate(sciREG, 110);
    while(1){
    GPIOToggle(LED1);
    sciSend(sciREG,38,"Starting a test on the SCI register\r\n");
    GPIOToggle(LED2);
    sciSend(scilinREG,38,"Starting a test on the LIN register\r\n");
    }

The GPIO routines are my normal driver routines.  The sciSet and sciSend are the HALCoGen routines not using any interrupts or anything else.  Note that I set the baudrate to 110 (R-e-a-l slow!) and sent 38 characters.  That it, it should take about 3.8 seconds to print.   And indeed the light pattern changes at a rate of approximately every 4 seconds.  

 I have a terminal connected to PC104 pins 88 and 92 and set for 110 baud connected and at first saw nothing.   Then I reversed the rx and tx pins and.....

Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register
Starting a test on the SCI register

SO!  Either I have the colors wrong on my serial-to-USB connector, or they are backwards on the blinky board.  Will figure out which next, and then try higher speeds.

73,

Burns Fisher, WB1FJ

AMSAT(R) Engineering -- Flight Software