Out of serial ports..any options?

[ggerhardt]

Hi,

I saw the day coming and thought I'd be able to configure my way out of this, but I realize now that I'm out of serial ports.

1 - SL30 Nav/Com
2 - SV-ADSB-470
3 - SV-XPNDR-261
4 - Garmin 300XL (pressure altitude data)
5 - SV-GPS-2020

I want one more so I can make use of the wonderful data stream SV puts out.  I've been contemplating an arduino device to display some additional info using this.  But, looks like I'm out of luck.

Dynon - any ideas for adding serial outputs?  Here's a couple I've had:

Write a driver for a USB-to-serial device like this one: http://www.bestbuy.com/site/dynex-1...ffcode=pg199014&ksdevice=c&lsft=ref:212,loc:2.

Looks like you have a few pins available on the SV port, turn a few of those into software TTL-level serial outputs.  Clever folks can either use these to directly couple to arduino-like devices or put on a RS-232 level shifter.

Make a network device that has additional serial ports.

To be honest, you guys have painted yourselves into this corner by relying on RS-232 connections instead of network ones for the devices you make (GPS, ADSB, XPNDR), those should be network connections and leave RS-232 for third-party stuff.

Any, I'd love to see a solution to allow a few more ports.

Thanks.

Geoff

 

[vlittle]

I have devices (autotrim controller, stick shaker, auxiliary engine instrument display) that uses a serial port on my SV. I run the link at 115,200 bps and feed both engine and air data on the link. My devices just pick out the data they need. They are receive only devices, however.

Dynon could probably build an RS-232 Multiplexer that expands one 115200 port into several lower rate ports that would support additional links. Not that difficult in hardware but the SV software needs to support it and there would be constraints.

It's not easy to 'bit bang' general purpose IO to emulate serial ports. Some of my devices do it for configuration only, but you need hardware ports to be in place to offload the cpu to do real work. Even so, a serial port at 115200 bps keeps microcontrollers humming and I've had to count instruction cycles in critical loops to ensure integrity. For example my autotrim control has to use funky exponential math in assembly language to save cycles.

So... nothing is 'easy' once you have a production released product shipping in the thousands. I think that Dynon may suggest some work-arounds to your problem in the short term, but you may not have that extra port you want for doing things like I did. BTW when/if I add ADS-B to my Rocket, I will have the same problem. Come 2020, however, trans-border GA traffic between the USA and Canada will be virtually extinguished, so I may not bother.

Vern

 

[thibault]

Vern,

You said:

"Come 2020, however, trans-border GA traffic between the USA and Canada will be virtually extinguished, so I may not bother."

Please explain your thoughts on this.

 

[vlittle]

Many Canadians will not bother upgrading their GA aircraft to ADS-B.  It is expensive and there are no rebates.  With all of the annoyance of EAPIS, customs officials packing attitudes and now the cost of ADS-B compliance, it's easier just to stay in Canada.

On the other side, the Class 3 medical reform in the US will not be recognized in Canada, similar to what has already happened with the LSA medical rules.  You will be required to meet the Canadian Class 3 licensing standards.  You also have to deal with EAPIS.  It will be easier just to stay in the USA.

So we are building a regulatory wall that will effectively close the borders to many, if not most, private recreational pilots.  We are hoping that Transport Canada will adopt the US medical reforms, but that is very unlikely.  I doubt that the US will allow non-ADSB aircraft fly into controlled airspace just because they are harmless Canadians.

Sorry for the thread drift.

 

[jakej]

Vern, you're more than welcome down our way  ;D ;D

 

[vlittle]

As long as you have more serial ports down under[ch128526]

 

[ChiefPilot]

4 - Garmin 300XL (pressure altitude data)

If the 300XL is interfaced to the Skyview via ARINC-429 would that free up the port you need?

 

[ggerhardt]

I do use ARINC for the 300XL, but it needs a serial port, too, to receive pressure altitude. Perhaps I'm duplicating and it receives this over ARINC, as well and I don't need the serial port. Maybe I'll disconnect it and see if it complains!

I fly back and forth b/w the US and Canada multiple times/month (Live in MA, have a house in NS). I wondered about Canada recognizing the change in medical req's. May have to keep up my 3rd class medical...

Geoff

 

[mmarien]

Just returned from the US. eAPIS, flight planning, customs and weather didn't stop me. Definitely annoying at times, but not insurmountable. In 2020 I'll still fly cross border with the non ADS-B equipment I have. I don't make use of Class A, B or C airspace presently so I don't expect the 2020 mandate to change my flight habits.

 

[vlittle]

Can't even sneeze around Vancouver/Victoria without being in US class C. Last year, I had to get a letter from the FAA just to depart Victoria! Even our VRF checkpoints are in US airspace.

Murray, check your PMs about your EMS editor.

Vern