Help with connecting GPS to Cortex

VEX V5 General Discussion Technical Discussion
1

I needed to connect a Garmin GPS 18x to the Cortex’s UART port, but I discovered that I would first need to convert the GPSs RS-232 signal to a TTL signal for the UART. I found this board and was wondering if anyone could tell me if this is what I need: SparkFun Transceiver Breakout - MAX3232 - BOB-11189 - SparkFun Electronics

Also, could someone help me figure out which wire would go where on the board? The datasheet that Sparkfun provides isn’t specifically for this board and the labels aren’t very specific.

2

Looking at the breakout board and the general schematic.

You’re going from RS-232 to TTL.

So I’d take the TX from the RS-232 and wire that with the R1IN on the Board, and the RX from RS-232 to the T1Out on the board.

For the Cortex side, Cortex RX port goes to T1IN on the board, and the TX goes to R1Out if I’m correct.

Also, does the device have a DB9 connector or no? Because then I’d use something like this: SparkFun RS232 Shifter - SMD - PRT-00449 - SparkFun Electronics

3

This thread may have some helpful information:

https://vexforum.com/t/weird-response-from-uart-port/24924/1

4

Both the referenced sparkfun products should work. GPS communication is usually at a pretty low speed (used to be something like 4800 bps) but I’m not familiar with Garmin equipment so that may be different. Interfacing to the cortex using any of the available development options (although most difficult in EasyC) should be pretty easy.