[POTM] dAISy - A Simple AIS Receiver

[chicken 630]

@bluehash: serial over USB, once I get USB working that is :-\

At some point I will also give Bluetooth a try via the serial lines on the programming header.

[chicken 630]

Time for a status update.

 

 

I was busy with a lot of business travel over the last few months. On the upside, I stayed at some places close to busy ports giving me the opportunity to debug the software issues that plagued the standalone version of dAISy. So dAISy USB is finally alive and kicking.

 

Back home, I did a field trip to Seattle and recorded this short video to show it in action.

 

I'm currently reworking the USB side of the PCB as I missed a few crucial things. As discussed in another thread, I had to patch in a few resistors to make it work.

 

I'm also contemplating to add a shield on top of the radio IC in the hopes to increase sensitivity. Does anyone know if that's worthwhile?

 

Next up is a proper case. Does anyone know a finger-sized case with holes for a USB plug on one end and BNC or SMA on the other?

 

[abecedarian 330]

How about run a USB pigtail out the side of an Altoid's tin and SMA connector / pigtail on the lid?

[chicken 630]

How about run a USB pigtail out the side of an Altoid's tin and SMA connector / pigtail on the lid?

 

Well, I was thinking about something a bit more "professional" than that

[abecedarian 330]

Yeah, I was half joking.

Maybe a little overkill but what about a 2.5" USB hard drive enclosure?

Or maybe this project enclosure?

[chicken 630]

The USB battery boosters are more the shape and size I'm envisioning:

https://www.google.com/search?q=power+bank+2600mah&source=lnms&tbm=isch

[abecedarian 330]

Oh... like these?

[abecedarian 330]

Here is round one.

 

[chicken 630]

Ah, the first one looks promising.. just ordered one.

[abecedarian 330]

For $4, it's probably worth the experimentation considering it's aluminum and would probably help the shielding you mentioned. Maybe go to an SMA bulkhead type connector for an external antenna, but BNC might be a fit too; either may be doable with a slight tweak to the board dimensions.

 

If I wasn't over the hill from Newport, Laguna and other marinas I'd probably ask to buy one from you for the novelty factor alone.

[JoeBro12 1]

As a sophomore in Electrical Engineering and and avid sailor, this thread is just awesome.  Do you plan on releasing the project source code and schematics for your new design?  This would be such a fun summer project to try to add to my boat.

[chicken 630]

Do you plan on releasing the project source code and schematics for your new design?

 

Not sure yet, whether I'll also make the USB version open source as I'm contemplating making this an actual product.

 

But happy to share individually. Send me a PM.

[PaulTech 2]

very interesting, have already my boards from osh and I'm now wating on a reply from my local distributor for the si4362, Mouser wanted $39 for postage.

I have been in research mode for an AIS receiver for a few weeks when I finally stumbled into this project.

I see the si4362 is a transceiver chip so it should be possible , with a GPS module, to make a AIS transponder.

What size is the crystal , just looking at the board it looks like 7mm x5mm.

[PaulTech 2]

very interesting, have already my boards from osh and I'm now wating on a reply from my local distributor for the si4362, Mouser wanted $39 for postage.

I have been in research mode for an AIS receiver for a few weeks when I finally stumbled into this project.

I see the si4362 is a transceiver chip so it should be possible , with a GPS module, to make a AIS transponder. Whoops saw this mentioned in an article, just checked definately receive only.

What size is the crystal , just looking at the board it looks like 7mm x5mm.

[chicken 630]

very interesting, have already my boards from osh and I'm now wating on a reply from my local distributor for the si4362, Mouser wanted $39 for postage.

I have been in research mode for an AIS receiver for a few weeks when I finally stumbled into this project.

I see the si4362 is a transceiver chip so it should be possible , with a GPS module, to make a AIS transponder.

What size is the crystal , just looking at the board it looks like 7mm x5mm.

 

The Si4362 is only a receiver. For a transponder, you will have to look into the Si446x family.

http://www.silabs.com/products/wireless/EZRadioPRO/Pages/Si446x.aspx

 

However note, that GMSK encoding is only supported indirectly, which is fine for receivers but might not be up to spec for transponders. See this discussion: http://www.eevblog.com/forum/beginners/need-some-help-with-si4362-%28gfsk-vs-gmsk%29/

 

As for alternative sources for the IC, it looks like Farnell/Element14 has some in stock:

http://www.findchips.com/search/si4362

 

I currently use two kind of crystals, the larger footprint (5x3.2mm) is for this one:

http://www.mouser.com/Search/ProductDetail.aspx?R=7B-30.000MEEQ-Tvirtualkey57230000virtualkey717-7B-30.000MEEQ-T

 

I also use this smaller crystal (3.2x2.5mm) which is a bit out of spec as per Silabs application note (to large load capacitance), but works just fine for me:

http://www.mouser.com/Search/ProductDetail.aspx?R=AM-30.000MAGE-Tvirtualkey57230000virtualkey717-AM-30.000MAGE-T