If Speed and BW are not in the criteria, surely IRDA connection would work fine as well.
Regarding the Hardware interfacing is concerned, I found this link, check it out if it helps.
I (possibly) found a better and cheaper and easier way to connect any phone to a PIC.
It's just an idea, I'm currently studying its feasibility.
Almost any phone has an headset port: this port "emits" an audio signal, i.e. a variable voltage.
I can easily drive this voltage by making the phone playing a midi tone (it's just a matter of adding a couple of lines to a standard "HelloWorld" midlet).
So I can decide when and how long to emit sound from audio port.
Some PICs have an Analog/Digital converter pin.
So, adding a simple RC filer to the audio output, just to obtain a constant voltage rather than a 440 Hz sinusoid ("A" note), should be enough to enable PIC to detect and process signals from the phone.
Once figured out if my idea is feasible... here it is what we could use it for!
The cheapest (33$):
Further ideas for the project (once it is working):
we could drive the cellphone connected to the pic, by writing a program on another phone, which, once we change settings as we like, updates a web page by means of http request (which requires very low data amount to be sent over GPRS), and then starts a call to the remote phone: upon receiving the call, the phone reads those data and acts accordingly.
That should be much cheaper than using SMS to communicate with the phone.
Updating a web page is very easy:
It's a python source, but method is easily portable to any platform.
Main problem is how to get remote phone connected to network without asking for user permission! This can be overridden simulating keypress with python, but it's not possible on a java-only phone.
So, what about "push methods" to send data to mobile devices? How does it work?
Last edited by cassioli; 2008-09-30 at 14:44.
I did it!
- a PIC with analog comparator (I used 16f628a)
- nothing else!
Just connect your headset to the comparator input, and write a proper SW for the PIC which writes "1" on a pin upon detecting "1" on C1OUT (Output of comparator).
I'll not give out more details, as I think such a simple&cheap circuit could be used for dangerous projects too , so if you want do build it, it's up to you.
I just discovered it's possible and that's all. Sorry.