Joshua's RV-9A Project

Made up the service cable tonight; a DB-9 to connect to a PC on one end, and a 3.5mm plug on the other.  I’m installing several 3.5mm jacks throughout the plane as places to tap into serial lines for programming and service:

• Left Pmag (connects to control port)
• Right Pmag (control port)
• NavWorx ADS-B (maintenance port)
• APRS transmitter (normalling jack; interrupts GPS signal for programming)

I headed to the shop to test the cable, and soon discovered that I had wired the jack for the left Pmag backwards; TxD was RxD and vice versa.  Swapped that with the soldering iron, and I was able to connect with both Pmags.

Also verified that the GPS was sending its data out, as I wasn’t able to get it to display on the transponder the other night.  It’s definitely outputting, so some more research on the GTX 327 had inconclusive results as to whether or not the box would take NMEA.  It’s supposed to work for sure with Aviation format, as output by the GNS430 (and presumably the new GTN series), to which it’s wired.  I had planned to run NMEA into those pins from a mating connector, which would feed the transponder and autopilot, but now I’m not sure if it’s necessary, assuming the transponder has no use for it.  I suppose the autopilot can still read it, if I buy that before the GNS/GTN.

This entry was posted on Tuesday, March 29th, 2011 at 10:20 pm and is filed under Electrical. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.