You can use an old Sony Ericsson phone as free or dirt cheap GSM “shield” for sending and receiving messages (turning on/off some device), sending collected data (as e-mail, SMS, MMS) to any location, receiving or initiating calls – for example if an alarm is triggered, or to listen what is going on in remote location - but also by using ordinary AT commands it is possible to set and read phone’s timer, clock, calendar, use basically any phone’s available function. This is where it gets even more fascinating…
You can use camera, keypad as input device to Arduino, audio recorder/player, some voice control (“magic word” function), Bluetooth (it is limited to sending notes, files and contacts – but it can be used in some projects). All these options require only two pins to connect to Arduino.
It is also possible to use java applications on the phone and use it for any other purpose (for instance remote BT control). You can easily develop java programs for phones the same way you program Arduino using almost the same C environment - check: http://mobile.processing.org/
Some phones have built in simple thermometer (for charging). You can use display and some ready user’s interface SonyEricsson functions to simply display data (as a note, sms, dialog “window” or graphically as “gauge”). There is also a way to use it with keyboard as input device (report key event mode), to select choice (yes/no), to set a value (gauge input function- you adjust the value by joystick and send it to Arduino, as text input - you can write text with phone’s dictionary and any available in the phone writing methods and send the whole ready text to Arduino. With some provider’s functions it can easily gain another layer of functionality for Arduino projects – for example you can very easily make car alarm which can notify by phone about triggering or any other event– but also many providers can send information about location of the phone (for example stolen car) (and send even a map where it is).
By AT-commands all the key’s presses can be emulated, including joystick and special function keys – so everything you can do with old, good SE phone – Arduino should be capable of doing as well
For AT commands and how to use them search for : “Developers guidelines - AT commands
for Sony Ericsson phones”.pdf
here is one - but preferably older version from 2005-2007 is a littlie more accurate for the older phones.
http://developer.sonyericsson.com/cws/download/1/707/466/1277362028/DW-65054-dg_at_2006--10_r17a.pdf
This is the list of the Sony Ericsson phones which have Rx-Tx connection, which are very easy to connect with Arduino:
2218z,
A2618s, A2618sc, A2628s, A2628sc,
F500, F500i,
J200c, J200i, J300a, J300c, J300i,
K300a, K300c, K300i, K500c, K500i, K506c, K508i, K600, K608i, K700, K700c, K700i,
P800, P802, P900, P908, P910a, P910c, P910i,
R300d, R300LX, R300z, R310s, R310sc, R320s, R320sc, R380e, R380sc, R380s, R380WORLD, R520LX, R520m, R520mc,
S700c, S700i, S710a,
T200, T202, T20e, T20ec, T20s, T20sc, T238, T28s, T28sc, T28z, T28WORLD, T290a, T290c, T290i, T292a, T29s, T29sc, T300, T306, T310, T312, T316, T39m, T39mc, T60c, T60d, T608, T60LX, T610, T61c, T61d, T616, T618, T61LX, T61z, T628, T62u, T630, T637, T65, T68, T68i, T68ie,
V600i, V800,
Z1010, Z500a, Z502a, Z600, Z608, Z800i.
Besides that, some old Siemens and Motorola phones have serial connection too.
Check out serial pinouts and some other SE phones here:
http://www.8051projects.net/out.php?link=http://pinouts.ru/CellularPhones-P-W/erics_t28_pinout.shtml
On the other hand -phones like: D750i, K310a, K310i, K310c, K320i, K510a, K510i, K510c, K610i, K610im, K618i, K750c, K750i, K758c, K790i, K790c, K790a, K800i, M600i, M608c, P990i, S500, V630i, W710i, W710c, W712a, W850i, W950i, Z520a, Z520i, Z520c, Z525i, Z525a, Z530c, Z530i, Z550c, Z550i, Z550a, Z558i, Z558c, Z610i, Z710c, Z710i, W300i, W300c, W550c, W550i, W580, W600c, W600i, W700c, W700i, W800c, W800i, W810c, W810i, W830i, W830c, W900c, W900i, W958c, and newer have mostly implemented some newer protocol so they don’t support straight Rx-Tx connection with Arduino serial. But some phones (perhaps units produced early or something) like K750i probably can support RxTx, but I am not sure.
To connect it is best to buy phone-RS232 cable, cut off the computer plug and connect wires to Arduino this way:
Phone Tx (Transmit -pin5) connect to Arduino Rx (Receive);
Phone Rx (pin4) connect with Arduino Tx;
ground Arduino connect to ground of the phone(pin10).
It woks like this but it is probably better to use a voltage divider or resistor to lower the voltage from Arduino’s Tx to around 3V. I use 2kOhm resistor between Arduino Tx and phone Rx and it works fine for K700i.
It is also possible to connect 5V form Arduino to phone pin 11(charging) – but better don't use it for charging – only for maintaining battery voltage, for normal phone operation. This connection can also power Arduino – but I am not sure if this is the right thing to do it this way.
Remember to cut off the RS 232 plug (plug which is normally connected to computer) – there is entirely different voltage generated inside the RS232 plug – you may destroy Arduino if you connect somehow RS232 plug to Arduino (the circuit inside the plug takes power from computer’s side of RS232 to intensify and convert voltages).
If you don’t have Bluetooth both in the phone and in computer (bluetooth dongles for computers are very cheap now) – you may want to buy two RS232 cables –one use for connecting to the computer so you can examine how the phone responds to AT commands and then implement this knowledge in Arduino project. But most convenient is to use BT connection with HyperTerminal (just to see if and how commands works before you start playing with AT commands sent from microcontroller)…
There may exist USB cables for some of these phones which have RxTx too – in this case there is only USB plug but the communication takes place by Rx Tx “protocol”. If you find that cable you can use it as well (but it is not necessary to cut of the plug like for RS232 cable, because there is no voltage translation in the USB plug).
This topic relates to the other ones form the old forum:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1290601471/all
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1227581530/0