Seatalk to signalk on a Raspberry Pi

[GHA]

Latest version of signalk has seatalk as an input connection option >

feature: add seatalk connection type by tkurki · Pull Request #1064 · SignalK/signalk-server-node

Not tried it yet, but should be possible now to get seatalk into signalk and then to nmea0183/2K, whatever you want.

Need to get the levels down to 3.3v though, before I've used a rs232/ttl adaptor before powered by 3.3v, which outputs 3.3v.

might work.....

anyone had a go yet?

Careful down at those pins on a Pi, easy to blow..

Will be great if it works though

Onensource is just great!

 

[dolabriform]

Latest version of signalk has seatalk as an input connection option >

feature: add seatalk connection type by tkurki · Pull Request #1064 · SignalK/signalk-server-node

Not tried it yet, but should be possible now to get seatalk into signalk and then to nmea0183/2K, whatever you want.

Need to get the levels down to 3.3v though, before I've used a rs232/ttl adaptor before powered by 3.3v, which outputs 3.3v.

might work.....

anyone had a go yet?

Careful down at those pins on a Pi, easy to blow..

Will be great if it works though

Onensource is just great!

Thanks for posting this. I know what I need to pay with next !

I've also been looking for some code to read seatalk on an arduino / esp.

 

[GHA]

Would be better if I could get it working.....

There is a sketch for arduino around on the web with a bespoke soft serial library which can cope with the weird 9 bit serial that seatalk uses.

 

[dolabriform]

Would be better if I could get it working.....

There is a sketch for arduino around on the web with a bespoke soft serial library which can cope with the weird 9 bit serial that seatalk uses.

ooooo I'll have a hunt for that.

I'd love to make a box that does bi-directional translation between seatalk and NMEA 0183 + 2000.

 

[GHA]

I'd love to make a box that does bi-directional translation between seatalk and NMEA 0183 + 2000.

That would be called raspberry pi running openplotter/signalk
Though not so sure about sending seatalk, but bet the signalk guys will get it sorted before long.

This works!!!! Sort of. Bit of a runaround, the st40 bidata wouldn't drive a rs232/ttl chip. It would just get pulled to ground. So sent the st40 output to a mosfet with 12v on the drain and fed that into rs232/ttl which seemed to work ok, output 3.3v.

Then spent a while figuring out that the hifiberry amp plugged into the Pi was using the same pin, so find a vacant pin and bingo, straight in.

Data seems a bit odd though, the temperature readings were weird for years so that might be OK, log or average log doesn't seem to read yet but trip seems maybe right. No sign of depth, but out of the water, maybe it isn't sending.
Anyway, very first version of the app so a few bugs to sort no doubt.
But it works!!
Maybe optoisolator would be a better way to go to get the voltage down to 3.3v

 

[TernVI]

I use these level shifters to buffer from 3v3 to 5v
4-Channel 4CH Logic Level Converter Bi-Directional Shifter Module 3.3V-5V | eBay
If you only need one direction, then a couple of resistors or a simple transistor will do the job.

 

[dolabriform]

I use these level shifters to buffer from 3v3 to 5v
4-Channel 4CH Logic Level Converter Bi-Directional Shifter Module 3.3V-5V | eBay
If you only need one direction, then a couple of resistors or a simple transistor will do the job.

Level shifters work well but I'd prefer an opto-isolotor for the separation.

 

[dolabriform]

That would be called raspberry pi running openplotter/signalk
Though not so sure about sending seatalk, but bet the signalk guys will get it sorted before long.

This works!!!! Sort of. Bit of a runaround, the st40 bidata wouldn't drive a rs232/ttl chip. It would just get pulled to ground. So sent the st40 output to a mosfet with 12v on the drain and fed that into rs232/ttl which seemed to work ok, output 3.3v.

Then spent a while figuring out that the hifiberry amp plugged into the Pi was using the same pin, so find a vacant pin and bingo, straight in.

Data seems a bit odd though, the temperature readings were weird for years so that might be OK, log or average log doesn't seem to read yet but trip seems maybe right. No sign of depth, but out of the water, maybe it isn't sending.
Anyway, very first version of the app so a few bugs to sort no doubt.
But it works!!
Maybe optoisolator would be a better way to go to get the voltage down to 3.3v

Nice setup

I know it can be done on a pi. but that requires booting a full OS. I'd like to get it done on a esp / arduino and replace the E85001 & Actisense NGW-1 combination I have at the moment.

 

[GHA]

Not doing that great, the pigpiod library somehow interferes with my hifiberry amp plugged into the Pi which only plays web radio half speed with pigpiod running,

Edit- a little light, you can start pigpiod manually with a "-t 0" option which makes it use PWM leaving PCM for the audio. Though still some port sharing to sort out, chronograf & pigpiod both use port 8888.