Discussion in "Embedded GSM Development" started by    abbas1707    Apr 29, 2007.
Sun May 06 2007, 01:06 pm
good.. i hope you got the desired results!
Sat May 19 2007, 06:19 pm
hi ajay!
how are u?? i was bz in my exams dats y i was away from forum and my projects.yesterday i tested my program with my circuit but unfortunately there was no response from cellphone!!
i want to ask u dat when i transmitted AT and carriage return from microcontroller...will cellphone transmit OK or somthing else???
i directly connected the rx and tx pins of controller to cellphone pins.
but there is nothing.i dont understand where the problem is... code is same as i posted u before. plz give me some idea!!!!!!!!!!
Tue May 22 2007, 04:15 pm
well you first need to test your program on the PC.. i mean.. simulate it.. you become the phone.. connect your hardware to PC and in hyper terminal you will get AT commands you give the reply to your controller and see how your controller replies.
this way you can check whether you controller is doing exactly what you want.. i hope this will help you

forgot one thing.. in your connections.. u connected RX and TX but what about GND? without that nothing will work...!

[ Edited Tue May 22 2007, 04:19 pm ]
Wed Aug 01 2007, 01:51 pm
I am a step further in implementing the s/w on my h/w.I'll xplain in steps and thn my questions
1)I developed the s/w to send the init char 'U' 128 times and then the init string(to get h/w & s/w version of fone) of 10 bytes and waiting for the fone to answer back//all this in Keil and run it on Proteus simulation s/w,and it runs fine.(A baud rate of 2400 bauds was selected for this)
2)I have a data cable(FBUS) which connects to my 3310 to PC.I hv connectd my at89s52's Tx/Rx to a DB9 conn's(Tx/Rx)in the same ordr thru a MAX232.Now Max's Tx/Rx go to PC Rx/Tx (cross).(how do i send/attach my ckt dia?)
Now some things happen,rather dont happen...
1)On portmon(s/w to monitor serial port) nothing shows up after I run my prgm.
2)logomanager(pc suite to download logo/sms/etc to 3310) does not show fone as connected.And nuthin seems to b running.
3)On CRO also Tx/Rx are shown high(idle state)
4)hyperterminal does access the serial port though(but irrelevant of the target board)
My q's
1)in ur proj,what baud rates did u run the micro?as i see u hv some 7mhz crystal.is it mandatory to run it at 115kbps in accordance with the fbus rate?
2)what do u think may be wrong with the cable,which whn connectd to pc directly does show fone as connectd and whn done thru my ckt,does not.
pls reply cos i m stuck at this place
Tags FBUS protocolNokia 3310 FBUS protocolSMS controller nokia 3310
Wed Aug 01 2007, 01:58 pm
the above post is related to FBUS fones and NOT MODEM fones supporting AT commands//can u help me?
I'll tell more
Wed Aug 01 2007, 02:30 pm
As far as i know... F-Bus runs at 115,200bps not 2400... so i think you must check the speed. Also there is a condition for F-Bus that, the data terminal ready (DTR) pin must be set and the request to send (RTS) pin cleared.
Hope you take care of these things..

Regarding attaching image.. or circuit.. do the following steps:
1. upload image to www.imageshack.us
2. copy the direct link to image
3. and put image link in [img] tags
for example:
[ i m g ]link to image[ / i m g ]
please remove space from the tags i.e. [img]
4. thats all...

[ Edited Wed Aug 01 2007, 04:02 pm ]
Wed Aug 01 2007, 04:02 pm
hey thx for the reply...
can 115kbps be generatd using 89s52?
the thing u said about setting DTR and clearing RTS is just reqd for the FBUS cable,which has active electronics in it and so as to power it up,these 2 pins r needed(whr setting/clearing means DTR=+12V,RTS=-12V).I jus need to knw few things.
1)whn i connect micro-->max232-->fbus cable
PC wud not detect any activity on its serial port(PORTMON)
==for this I did this
a)made PORTMON active
b)connectd the FBUS cable(with DTR=1,RTS=0)
c)to jus chk ,turned on LOGOMANAGER (for nokia 3310)
but it shows phone as not connectd.
d)but whn i directly connect the FBUS to PC,Logomanager shows fone as connectd,and voila...PORTMON starts registering the activity
2)whn i start hyperterm and access com1,it will show sumthing on my micro(seen thru CRO)
all my routines of transmit and receive r running smooth in PROTEUS
Wed Aug 01 2007, 04:17 pm
well.. i used Logomanager to analyse the FBUS protocol. using the datacable for Nokia 1100. I used software called... "Serial Port Monitor" from HDD software.
I checked the status of pins RTS and DTR. the status shown is same as i explained above for FBus. Yes this is to enable the FBUS in case when you are using a data cable.
But you might be using some special cable just for FBUS. maybe..
to monitor what is going on your com port better you also download this software instead of just looking at CRO. So try using the "Free Serial Port Monitor"
Link: http://www.serial-port-monitor.com/
tell me what you see on the monitor.. the data sent and received etc.
Wed Aug 01 2007, 04:25 pm
ok i've ripped open my cable...and seeing few things
1)the powering is done thru 2 schottkey diodes(DTR n RTS connetd to this)
2)theres an opamp(mayb as buffer)..
3)most shocking Tx and GND shorted
r u online?..can i chat wid u say gtalk?
Wed Aug 01 2007, 05:09 pm
I think something is wrong with your cable. did u try using a datacable? its easy.. to use it.. check if your software is working.
and i forgot to tell u
you can achive 115.2Kbps on 89S52, use timer 2 for baud rate generation and crystal used is 11.0592Mhz

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