Recently, I've been messing around with my cellular telephone. I'm on the Nextel network (iDEN) and my phone is a Motorola Clutch i465, nothing too impressive. The only reason I have it around is because it is grandfathered on an old plan with unlimited incoming and my parent has agreed to pay for the bill, as I'll be attending RIT this upcoming Fall.
I'm usually behind on technology, especially wireless. So a few days ago I got the idea to connect my Clutch to my netbook via Bluetooth. After fiddling around and trying the Windows XP GUI to connect or dial a number (my intent upon doing this was for mere nostalgia), I figured out how to logon to Nextel's general internet (I think it's called GRPS). However, I quickly remembered back in the old days using Hyper Terminal for serial modem communication.
So, I connected the phone as a serial device and I looked up the Hayes command set. What do you know, it works! I haven't been up on my telco style modems since forever and apparently the old AT Hayes command set has been extended for cellular laptop cards (PCMCIA, etc...) to connect to the internet, some business people or those who travel often use these GSM radios connected to their laptops with special data plans so they can connect to the internet when there is no general wifi access.
I know the existence of GSM radios that accept SIM cards from Sparkfun. However in my opinion, they're relatively expensive to something such as a Pre-paid phone on GSM that accepts SIM cards.
The only problem I'm having (and perhaps that's because I have a Motorola phone that runs on iDEN) is that a lot of commands in leaked GSM specifications or functionality of extended Hayes that simply don't work. I have a feeling it's because of my particular phone and the network it runs on.
If you could find a cellular phone that had serial out or serial pins on the silicon on the inside, you could hook them up to your ATMega/Arduino's digital ports (making sure logic matches) and plug the headset jack into ADC and presto, you have a light weight radio (2.0 oz I think I saw some Tracphones) that can run where ever there is a GSM cellular network nearby. This would probably make it suitable for more things like having UAVs in semi-rural areas where GSM coverage is good but bad if the UAV in question is designed to operate where no towers exist or coverage is scant (you're relying on the backbone of the network and you're paying for minutes unless you have a SIM card from a family plan on another network). You don't even have to connect directly to it as a modem, you can have it use TCP/IP over the network, both methods are slow but both should be able to deliver ample telemetry data over something like 9600 baud maybe?
The problem I foresee is that I can't find any Tracphones with serial out. They use their mini-usb charger also as data and you're going to need circuitry or a USB UART on your ATMega/Arudino to translate the logic into serial-able logic.
If anyone can help me, I can do some things with my phone with the AT command set,
however my phone is having a problem making outbound calls, changing registers, etc...
I do the following:
[code]
ATD 123456;
NO CARRIER
[/code]
Any idea on Nextel iDEN and Motorola handsets?
I've got datasheets
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Replies
http://www.opengpstracker.org/
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1265259790
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1271023137/3
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1241418101
http://www.maxim-ic.com/app-notes/index.mvp/id/1790
http://hackaday.com/2010/02/23/serial-communication-with-cell-phones/
And me. :)
Careful, the phone has a 3.3v (3.7v?) interface and you may (well, probably) have to make a small, easy, physical modification to the phone to make it work; the suggested connector mechanically interferes with the phone case. Contact me offline if you need me to be more clear.
Yeah, it really will work.