Emitting NMEA messages

I would like to control a tillerpilot on a sailboat in a wireless way and to do that I might have to send NMEA-0183 messages. Are there libraries that can help me with that?

What I can glean from the documentation I have to send ascii encoded messages in a RS422-compatible manner (same as RS232 for my purposes) at typically 9600 bps (8N1). Sentences look like this:
$GPBWC,220516,5130.02,N,00046.34,W,213.8,T,218.0,M,0004.6,N,EGLM*11

I haven’t found NMEA mentioned on the wixel forum but I am hoping that some of the efforts on other systems could transfer but I have no idea where to look. Anyone tried this before?

Hello.

Do you want to generate NMEA sentences with the Wixel or just send sentences from one device to another?

- Ryan

Ryan, Yes, I want to send sentences from the Wixel. In reality, I need to reverse engineer a remote control that I have and see how it encodes the ‘turn to startboard 5 degree’ and ‘switch to autopilot now’ type information. I will then generate them depending on some user input with the wixel.

Before you do any Wixel app development, you can use the Wixel’s USB-to-Serial app to test your electrical connections and NMEA sentences with a terminal program on your computer.

There are a couple of Apps that do string manipulation then send the strings as bytes. For example, the radio_sniffer, and the test_adc apps.

Both of those apps use usbComTxSendByte, but you could use uart0TxSendByte/uart1TxSendByte to send the bytes via a UART.

The SDK documentation and Wixel SDK source code provide a lot of good information.

- Ryan