I’ve been meaning to assemble an “alarm” for my motorcycle for a while, but it’d be more like lo-jack than an alarm. It would ideally text me every minute if it’s moving, and trigger a relay that kills power to the engine. Problem is, I don’t really want to buy a new cell phone plan for it. I can’t use a radio because if it gets stolen, it might be more than a mile away.
A phone would also be better because I could easily implement my “dead-man’s-switch” idea, sending a text with gps location if I’ve been stationary at a weird angle for more than 30 seconds.
So, is there any possibility of using a prepaid “tracphone” from 7-11? It uses a sim card, but I’m sure theres some kind of verification going on behind the scenes. Anyone with a cellular module want to try this? The phones are only 10$, and it comes with 10 minutes, good for 40 texts, I think.
miron721:
So, is there any possibility of using a prepaid “tracphone” from 7-11? It uses a sim card, but I’m sure theres some kind of verification going on behind the scenes.
You would think that a SIM from one TracFone would be “compatible” in another, but it is not. The SIM card serial number and the phone serial number are tied together. They don’t tell you this anywhere. You find out when you buy a new phone and try to use the old SIM in the new phone and get “Unregistered SIM” on the new phone screen. So you call Tech Support, who will then tell you the good news…they cannot be swapped. Why does it work this way? “Because that’s the way The System is set up.”
Seems kind of stupid on their part. Why should they care which hardware is used to access the minutes you paid for? Good luck getting them to be reasonable…
Well, damn. Is there any other type of prepaid phone that works? A prepaid phone is 20$, a cell plan is like 50 a month.
I’m assuming that when it registers itself to a network, it sends out sim card number, serial number, etc. Is there any way to “spoof” the serial number? Or would it be possible to remove the tracphone’s modem and use that?
Keeping in mind I have no experience with cellular modems other than using a cell phone, there must be some kind of way to make it work. Perhaps even have it report how many minutes it has left.
I am working on the same type project except to my car. Right now I am tied into an opticoupler to detect when the alarm is activated. It then sends me a text message and an email. Check out http://www.opengpstracker.org I used the C168i phone and have it working using an arduino. It is prepaid, so when I feel like having an alarm, it costs me like 5$ per month on ATT.
You can get a prepaid SIM from AT&T. I have seen these work during the development stage with Telit designs. (I work for Symmetry Electronics and we are a franchised distributor for Telit).
Another route would be to connect with a Network Operator that is specific to M2M communications.
You can get a prepaid SIM from AT&T. I have seen these work during the development stage with Telit designs
I am failing to get an at&t go phone sim card to work. the at+cpin? command reports cme error 13 sim failure. Can you provide more details on your success?
First, I’m assuming your SIM works in the pre-paid phone that came with it?
CME ERROR: 13 indicates a generic SIM failure. Assuming you’re using a Telit module, you’ll typically receive this only if a) your SIM isn’t installed correctly or 2) you don’t have an adequate power supply connected to the Telit module. If you have another SIM you can try with the same module/board that might be a good way to diagnose the issue.
I have successfully used pre-paid SIMS (both AT&T and TMobile) for development – and never had any issues with 6+ SIMs over the last 24 months. I did have lots of problems with bad power supplies - the Telit sucks serious power on startup and network registration. Still my favorite modules though…
I just wanted to follow up so others may benefit from the info. I went ahead and bought another prepaid go phone. this time I never installed the sim into the go phone and when I registered the sim card I entered the imei # of the ge865 into the registration form instead of the one from the go phone. They accepted it and activated the sim. so now at+cpin? returns READY; and when suppling power to the module and holding my finger over the u.fl connector it will register to the network. I dialed the sim card phone number and saw RING RING RING in hyperterminal. LOVELY. One small step at a time I guess.
Here’s my experience using a GM862-GPS (I bought the eval kit from SparkFun) with an AT&T prepaid Go Phone SIM. My application wakes up every 15 minutes, reads some data, and then connects to my server via TCP and reports the data. The amount sent each time is very small, well under a kilobyte. Then the module and the micro go back to sleep for another 15 minutes.
This has been working fine for the last month or so, then suddenly two days ago the Telit module could no longer connect. It can register just fine, activate the GPRS context just fine, and everything else works the same as it always has, except the TCP connection always times out (+CME ERROR: 559). Placing the SIM into a regular GSM phone and using it to access any web page results in an error page (error code -2, whatever that means). If I try to “connect” using UDP, the module reports no errors but the data never gets through (UDP used to work also). The prepaid SIM has about $5 remaining on it, so it’s not that I ran out of money or anything like that. The SIM can still be used to make voice calls and send SMS text messages with no problems.
Also, if I swap the SIM from my regular AT&T (postpaid) phone into the Telit module, everything works fine. It seems that someone at AT&T simply disabled the Internet access for my Go Phone SIM. Why they would object is beyond me. My bandwidth usage is extremely low - < 1KB every 15 minutes, which is basically invisible next to all the gigabytes being sucked down by iPhones. But even if I was using a lot, I pay by the kilobyte, so it’s nothing but a money-making opportunity for them. Shutting it off makes no sense to me; then again, I suppose it’s folly to expect rational thought from a giant corporation like AT&T. :roll:
Anyway, if you’re looking for a SIM for your Telit module, you’ll probably want to avoid AT&T. I’ll try T-Mobile next; maybe they want my business.
I found that I get SMS from Vodafone every time I add credit. They come from the 1555 number. If I send a SMS to 1555 number I get a standard reply informing me of the credit level. I can do that even when credit is $0, I know, I had a ping-pong loop the first time the balance when to 0. I would send it my Lat+Lon and it would tell me I had $0 credit. There were a few hundred SMSs before too long, luckily it was a free SMS …
I use a vodafone pre-paid sim in my GM865 Quad here in Australia.
swarga, I have been using t-mobile with good success. I am only using their $15 unlimited text option. I’d be interested to learn more about your database and how you are storing location information if you don’t mind sharing.
According to AT&T’s text messaging terms, you are prohibited from using their service for any type of automated data feeds. Here is an excerpt:
“Examples of prohibited uses include, without limitation, the following: (i) server devices or host computer applications, including, but not limited to, Web camera posts or broadcasts, automatic data feeds, automated machine-to-machine connections or peer-to-peer (P2P) file sharing; (ii) as a substitute or backup for private lines, landlines or full-time or dedicated data connections;”
I think you can’t do that. If you want something for your motorcycle, you can just buy a tracking device, which can update you anytime. Also, make it a habit to check your vehicle from time to time.
Buy a tracker…phooey. I designed my own. Check http://ohararp.com/blog for more details. Using the GM862 and twitter with a T-Mobile Sim makes it pretty easy.
This is prbably beating a dead horse, but can’t you simply buy a pre-paid sim card from yur favorite network and stick that into this project/module? (I have a Virgin Mobile prepaid sim card laying around for just this kind of thing.) That would seem to be the simplest solution.
Why they would object is beyond me. My bandwidth usage is extremely low - < 1KB every 15 minutes, which is basically invisible next to all the gigabytes being sucked down by iPhones. But even if I was using a lot, I pay by the kilobyte, so it’s nothing but a money-making opportunity for them. Shutting it off makes no sense to me; then again, I suppose it’s folly to expect rational thought from a giant corporation like AT&T. :roll: