gk20,
Looking at the data sheets and documentation for the devices specified, I think the MAX3232 board should work. The connections (based on my interpertation of the data sheets) will be as follows:
Connect the following 3 pins/wires together
- Garmin Wire #2 (red) vin
- MAX3232 3V-5.5V
- Cortex +5V
Connect the following 4 pins/wires together
- Garmin Wire #3 (blk) ground
- Garmin Wire #5 (blk) ground
- MAX3232 GND
- Cortex GROUND
Connect the following wire/pin pairs
- Garmin Wire #4 (wht) TXD (transmit data) to MAX R1IN
- Garmin Wire #6 (grn) RCV (receive data) to MAX T1OUT
- Cortex Data In (Rx) to MAX R1OUT
- Cortex Data Out (Tx) to MAX T1IN
The 5V from the Cortex will power both the MAX and the Garmin IO (requires an external power source)
Try to verify this wiring before powering the devices as I may be in error. The following locations are where I found the various spec sheets.
Garmin
http://static.garmincdn.com/pumac/GP...Tech_Specs.pdf
Cortex
http://content.vexrobotics.com/docs/...ev1-PINOUT.PDF
MAX3232 Breakout Board
https://www.sparkfun.com/products/11189
MAX3232 Schmatic
http://dlnmh9ip6v2uc.cloudfront.net/...eakout_v01.pdf
SP3232EP Chip
http://dlnmh9ip6v2uc.cloudfront.net/...3232EBCA-L.pdf
Mike