An update on my GSM/GPS project

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Fyod

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I just wanted to let you guys know how my project is coming along because I'm really excited today since I got it to blink! Not that that is a huge accomplishment, but I now know that half-ish of the work is done, the rest will be programming.
What it is is a GSM/GPS backpack for any Teensy. Features include:
- Lipo 1 cell charger w/ 4.5-6.5V input
- Full GPS/Glonass capability
- GSM class 12 GPRS capability with a nano SIM slot
- CAN-BUS input with a switch for two CAN-BUS lines

Due to what I think is an amazing size (same as Teensy), the only downside is the bottom pins can't be used unless a very thin flex were soldered on.
Nonetheless, only 8 IO pins are used (12,13 are dummy spacers right now). The boards are only about 1.5mm apart.
Think of all the things that can be done with this!

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Hope to update soon with more info!
 
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Finally had time to return to this project.
After a weekend of tinkering, I have successfully locked GPS (5-7 satellites indoors!, 13 outside), successfully logged in to the GSM network and sent/received SMS messages.
Now I'm going to tie GPS to GSM by sending location via SMS and hopefully to a web service.
Then last step will be to tie in CAN-BUS data and send that in the SMS as well.
I'm really excited that the PCB works with only two minor tracing mistakes and something I only had in my thoughts last fall is coming to life!
 
This is great! I am planning something similar with only the GPS part of the add-on.The board will be l0.7 x 0.8 in and fit on top (or bottom, I suppose) of the Teensy at the non-USB end just like my nRF24L01+ radio add ons do. Don't know how well the pcb antenna will do with reception; I'd be happy with five satellites!
 
I have tiny SMA connectors on my board and external antennas. The GPS is an active puck that's 13x13x6mm and the wire length is only about two inches.
I could make a TeensyPhone with all the features that are available :D Though my goal is to have the abilities of GPS/GSM trackers, plus a lot more, in a package that weighs a couple grams.
 
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Mine is almost ready for the pc fab. Here is what it looks like now:

test.png

The big unknown is what kind of reception I will get with this pcb antenna. I would like a completely untethered solution if possible.
 
What GPS is being used? Some, (like the NEO-M8N) support RTKLIB and so can be used to get centimeter level accuracy.

I find the ESP8266 useful for such things (ie, wifi as an alternative to GSM or bluetooth).
 
Would anyone be willing to play around with one of these prototypes in return for trying out programming some simple GSM gprs and CAN code?
 
Awesome work, gentlemen!

I found GPRS tough to get right and I hope you have an easier time. I used the SIM900, and while the documentation re: how to send SMS, etc. was straightforward, the interesting bit (to me) of putting stuff on a google docs server via GPRS was pretty difficult. It may have gotten easier in the meantime, however, with more examples to use as a crib.

I expect designs with a exposed antenna (i.e. like Onehorse's) to do well because the teensy doesn't shield them. Fyod, is your design using one of those integrated ceramic chip antennas? If so, how does the unit behave if the teensy is facing up? I'd expect some shielding issues but I am happy to be wrong!
 
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Both external. The GSM is a flexible "sticker antenna" and GPS is a tiny active patch.

I have been trying gsmlib.org (a great lib but weak support) and cookinghacks also has some nice examples, for sim900/908 atleast.
I'm basically just changing the AT commands and following the AT manual where needed.


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Fyod said:
Would anyone be willing to play around with one of these prototypes in return for trying out programming some simple GSM gprs and CAN code?
Click to expand...

Certainly! I can do the CAN code in my sleep. CAN/J1939? I've put it on most of my products since 1997. I'll try to PM you through this forum.
 
I'm using an Origin 4400 Nano Spider module. The first board I assembled didn't get any reception, so I sent it to Origin so they could help me diagnose the problem. They suggested a chip antenna so I have another version of the board I showed in #6 above which is slightly smaller (18 mm x 18 mm but still to be mounted untethered onto the non-USB end of the Teensy. When I get this to work I'll report here. Ultimately I would like to sell these on Tindie for about $50.
 
EK701 said:
Very nice! Do you have a BOM and/or schematic available?
Click to expand...

Thanks!
I'm can't make them public at this moment as I have a couple partners interested in investing in this project, but I could sell a few if there's interest. The code is open.

I also forgot to add that I currently have everything on the board working, with data being sent to an SQL server every 10s, calls, SMS. We are currently testing on e-bikes, grabbing the controller data (location, voltage, temp, distance etc.) with the ability to block the motor upon SMS if needed. The size is tiny enough to stuff into handle bars, seats, etc. Really cool stuff.
 
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@Fyod Do you have any updates on your board? Can it be purchased? If so, where? Very interested in incorporating it into a project I am working on.
 
i would be interested in buying too. My son is autistic and we use a gps from a commercial provider that sends us an sms when he leaves a known geofence (for safety) .... even though I'm a beginner (ok I'm a bit of a noob) , having a look at this would be really satisfying.... obviously I'm not thinking about replacing our gps EVER with anything I made!! But it would be a neat thing to know about. I'm getting addicted to teensy and coding ...I live in NZ and the gps provider we use is US, so I'm guessing there are no 'compatibility' problems.
 
@bringfire, @adrian, @ggregory8: I'm testing a new DC/DC converter as I write this and I should have results by tomorrow.
I'm in the EU, but the only difference could be GSM bands, but the module supports the usual quadband frequencies, so there should be no issue anywhere.
 
What sould you need to make a number of system? You say you have a couple of partners interesred in investing, have they put their hands in their pocjets yet? If not i would be interested as we may have the other half of your solution you may be interedted in.
pm me if youre interested.
ian
 
Hey Fyod! That's awesome! I look forward to that product! I have no need for one at the moment, but the graphic, etc. show great attention to detail/design/etc.
 
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