JP of the Heavens Continues!

Well it has been a while since i have last posted. as you may recall from my last entry the cell phone module i picked for our project was probably not a great choice. And guess what! It was even a worse choice than i previously thought! YAY!



But seriously. i want to make it perfectly clear, if you are going to do any kind of cell module hobby project, or hell even prototype, just get this

ADH8066 GSM Module
(SparkFun - images are CC BY-NC-SA 3.0 )

and then get this

ADH8066 GSM Breakout
(SparkFun - images are CC BY-NC-SA 3.0 )

or i guess if you wanted to be super extra fun you could get this

ADH8066 GSM Evaluation Board
(SparkFun - images are CC BY-NC-SA 3.0 ) 

i personally think that the eval board is more than anyone should need.. but i guess it would be really simple to use because that usb acts as a com port on your computer and you can just connect to it with a terminal like PuTTY. The reason beyond the fact that you wont have to solder any .5mm pitch socket on to a breakout board that you took a combined 40+ man hours to find on the internet, that made the cell module that you got more expencive than the other more reasonable options is that you won't need to wire no less than 3 transistors to some control device (uC, button, robot monkey, etc) and you won't need to Any way. That is just one thing in hindsight i wish i could have done.

The next thing is the sim card. 

we were originally going to get this

T-Mobile prepaid SIM card

look at that beautiful thing. It is pretty great honestly, and it is cheap! 3 bucks online, with free shipping. *sigh* well. We called T-Mobile to ask them if it would be possible to get like 100 identical, which would be what we want the most. After talking to a small business rep/adviser we were told such a thing is not really feasible, which isn't too bad, it just means that each box would have it's own number. The database is setup such that that would work fine, so it isn't a big deal. I should have bought it online like weeks ago, but i didn't, i thought it would be better to go to a real store and buy one. well. Turns out there are no T-Mobile stores here... and the only cell phone i could get cheap was an AT&T goPhone.  So that is what i done got.

I didn't know at the time, but it turns out that these phones are quite notorious for their closed-ness. People have problems putting the card in even other goPhones let alone other AT&T phones. I have heard of no embedded project that worked with an AT&T goPhone SIM. ugh. So ya. 

Apparently it can work. But you have to activate it in the cell module your project uses. because the guy at the store did the activation it was locked into that phone. also apparently if i wait 180ish days it will auto unlock and i can then use it in my cell module... good thing i have to get it sending texts like... today... :/

anyway. ya.

The good news.

We are able to use the uart to send AT commands to the module, so we know that isn't broken. Theoretically we know everything to send SMS messages reliably. The problem is we have to present this week, and there is almost no way that we can get a good SIM in time. The AT command sequence is really pretty mundane. i mean. (assuming you can connect to the friggen provider) it should be a simple command 

to do it:

AT+CMGF=1

AT+CMGW="+some number"

text goes here then send a '^Z'

i mean easy.

o wells. 

MORALE OF THE STORY:
Don't use a gophone SIM card, just because they are cheap. (T-Mobile is cheaper anyway...)
pay a little bit more to get the breakout-able module of anything, ever. it is worth the time saved.