I'm trying to find the STUART TX and RX connections on the 20-pin GPIO breakout. I thought they would be IR_TXD and IR_RXD (pins 5 and 7 respectively), but those seem to be dead. When I write to /dev/ttyS2 (STUART), I see nothing coming out on either of those pins (I'm using an oscilloscope). If I run the same code using /dev/ttyS3, it works like a charm. Can someone throw some ideas my way?
While I'm pestering the board with this, can anyone tell me how I could use the other GPIO lines? I'd like to use one to trigger a buzzer, another to reset a GPS chip and maybe others to drive diagnostic LEDs, and I'm already using all four serial ports. Again, any and all ideas will be greatly appreciated. Thanks.