Setting up Phone
1) Setting up the Phone
It’s a bit tricky to get to the FBUS pins in Nokia 3310.They are below the battery.
Fig1.0 FBUS PINOUT (www.embedtronics.com)
There are special data cables for this and you can get it from a mobile/cable shop for around Rs 100/- (You will have to check if it’s an MBUS or FBUS cable though)
(Incidentally if you are in Pune, you can get it near Dagdusheth ganpati)
The cable looks like this
Fig.1.1 CABLE
The encircled part is the pins that fit in Fig1.0 (phone)
Note: To check whether the cable is FBUS/MBUS, remove the 4 screws (one is shown by arrow). If the Tx, Rx, Gnd are separate pins (not soldered together) then its FBUS. Some FBUS cables which have MBUS pin disabled have an unknown config, that I was unable to understand but surprisingly work well with Logomanager (nokia s/w).What I did was separate the pins in the connector, and use individual pins. But before this I cut off the DB9 end, and put a plain DB9.The cables DB9 has electronics in it. (See Fig 1.2)
Fig. 1.2 FBUS CABLE and Nokia 5110 pin out
If you are to use the above cable be sure to connect DTR and RTS as shown above else the cable will not get power, and you will be left wondering ‘what’s wrong with my schematic?’ This is because the cable when connected to the PC and accessed through Logomanager works fine.
But if you were not to use the above schematic, do following steps.
a) Cut off the DB9 portion(which houses above electronics)
b) Add a plain DB9 connector to the wires which are cut loose. Connect Rx to Pin 2, Tx to pin3 and Gnd to pin 5.
c) The phone runs on 3V, and our Microcontroller (haven’t discussed it yet) runs on 5V.So it will sure damage the phone. For this, just convert the 5V on microcontroller Tx side or correspondingly on Phone Rx side(simple voltage divider which converts 5V to 3V See Fig.1.3)
d) Nothing to be done on Micro Rx side because it works with 3V.
But apart from above steps you can directly solder wires to the FBUS (but be careful )
Fig.1.3 The schematic I used (Connect all necessary external components)
Hurray we have setup our phone for communication, and we are ready!
Fig.1.4 My Board