tc35 gsm modem related question

Goto page 1, 2 Next

EDAboard.com Forum Index -> Microcontrollers -> tc35 gsm modem related question

Author

Message

polarized

Joined: 13 May 2002
Posts: 74
Location: Europe

18 May 2003 17:08 siemens a35 at commands

Hi,

I have a question regarding the tc35 gsm modem. I managed to configure the modem in a way that it transmits the received SMS messages directly to its serial port instead of storing them on the internal SIM card.But after receiving each SMS message you have to acknowledge it with a specific AT command AT+CNMA. If this is not done, the tc35 is not in the mode in which the next received SMS message comes out on the serial port. The sms message is again stored on the sim card. So, what is the problem you will ask: if a whole group of SMS messages from different objects is transmitted from the SMS service centre at once towards the same gsm modem, I mean one after other quickly and rapidly, how can I manage to acknowledge each message. Would it be a good idea to use some kind of flow control like RTS and CTS nad is it possible to use the flow control when dealing with SMS messages? How deep is the internal buffer of the TC35 gsm modem? And also do you know how long is the period of the acknowledgment timeout?

Thanks.

cancel

Joined: 27 May 2001
Posts: 286
Helped: 11

20 May 2003 18:54 siemens a35 at command

hi ...

first of all .. you should write your apps that it will receive and buffer sms as first priority and will parse it later. receiving sholud be interrupt based ... second ... even in case that sms is stored to sim you can read it from sim and delete it from sim .. only disadvantage is that sim storage is limited. do not hesitate to reply when you need additional infos ...

regards

cancel

polarized

Joined: 13 May 2002
Posts: 74
Location: Europe

20 May 2003 19:25 tc35i send message pdu format

Hi Cancel,

I did not quite understand you. I would like to receive all of my SMS messages on the UART port, because to me it looks quite easier. On the other hand the SIM card is limited by its memory size, as you said. My problem is that lets say 50 different objects would send some data via SMS towards one GSM modem at the same time. It is not necessary to build the system in this manner, I could divide them into separate time intervals, but for the moment I plan to do it in the above described way. I wanted to ask some of you did anyone try to receive SMS messages in a manner like this when they come quickly and rapidly and can I interrupt a serial sequence like this with my acknowledgment command and are modems really full duplex machines?

Bye.

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

20 May 2003 19:35 siemens tc-35i gsm modem forum

I do something similar with Siemens GSM phones (much cheaper than GSM modems).

Depending on the type they buffer at least 10 SMS messages on the phones sim. As far as I know the GSM systems also buffers outstanding SMS messages (at least for 7 days) until the phone (modem) is ready to accept them.

It is no problem to retrieve one SMS after the other from the phone (Sim).

hope this helps ...

polarized

Joined: 13 May 2002
Posts: 74
Location: Europe

20 May 2003 19:48 how to send sms the greek char xi tc35

Hi,

Can you send sms messages in text mode using ordinary Siemens mobile phones or you use the PDU mode? Do you use the phones together with microcontrollers or you use them with PC machines? How complicated is the PDU mode if you use it and what commands do you use to for example send an SMS message or to receive one?

Regards.

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

21 May 2003 6:08 modem tc35i

Siemens phones only support PDU mode.
I am using the phones together with 8051 and Pic microcontrollers.

Look for my posts and you will find a lot about this.

I do not remember the commands exactly but I will look them up for you and post them here.

regards

cancel

Joined: 27 May 2001
Posts: 286
Helped: 11

21 May 2003 7:16 tc35i sms

hi ...

find some links about sending sms via phone ... hope this helps ..
http://www.riccibitti.com/tinyplanet/tiny_article.htm
http://gatling.ikk.sztaki.hu/%7Ekissg/gsm/at+c.html

regards

cancel

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

21 May 2003 7:51 tc35 at+cnma

OK, here we go:
to check if the phone supports SMS (A50 does not!) "AT+CSCS=?" answer from the phone "OK" or "ERROR"

send SMS "AT+CMGS=" and here comes the tricky part phones before C45 are satisfied with a fixed "160" afterwards, newer phones want to know the exact lengt of the following PDU (unly userdata) in Oktets ...

after receiving this the phone answers with ">" afterwards you can send the pdu and to finish the whole process CTRLZ (0x1A)

answer from the phone (can take a few seconds) "OK" or "ERROR"

receive SMS "AT+CMGL=" and "0" for new SMS or "1" for SMS stored in the SIM

phone answers with:
+CMGL: 2,1,,155
0591347......

OK

which means SMS received the internal number is 2 (you need this later)
the following lines are the received PDU.

Problem is here that if more than one SMS was received (second number after the "2" in this case) you get all the PDU's for them too.

To simplyfy receiving I only read the first of X received SMS

After decoding the SMS you have to delete this SMS from Sim memory using the internal number (from above) "AT+CMGD=" and the above number (in this example "AT+CMGD=2")

answer from the phone "OK" or "ERROR"

or the phone answered just "OK" after "AT+CMGL.." which means nothing received

if SMS was received with this method you will have to repeat the above process with "AT+CMGL=1" which means stored SMS until you just get "OK" otherwise you do not realise if more than one SMS was received.

Please note that it took me to weeks to figure everything out and I post it here only because I also got help here often ...

best regards

polarized

Joined: 13 May 2002
Posts: 74
Location: Europe

21 May 2003 13:34 gsm modems siemens hayes wiev sim number

Hi,

This is good stuff that you post on the forum. I have a couple of questions more. When decoding the PDU sequence is it possible to use the following logic: I start from the most right position and when I approach the character which has a value which is the same as the number of characters I traveled from the most right position to the left I "proudly" conclude this is my data message codded in PDU format. Now, I have to decode it using the inverse rules how it was coded. Another question: I have a short example of decoding PDU messages, but only for 3 letters, "GSM". Of course, real world SMS messages are longer. What happens when I approach the 7 letter border? Do I start from the begining in the same fashion I coded the first 7 ascii letters? I mean the "rolling" technique.

Regards.

Google
AdSense
Google Adsense

21 May 2003 13:34 Ads

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

21 May 2003 14:14 pinout tc35

try this neat program, helped me a lot:
hxxp://www.nobbi.com/download/pduspy.zip

many etsi GSM standards can be downloaded here:
hxxp://pda.etsi.org/pda/AQuery.asp

this also helped me a lot:
hxxp://www.nobbi.com/sms_pdu.htm

also look here:
hxxp://www.elektroda.pl/eboard/viewtopic.php?t=41401&highlight=pdu

I have also included my decoding routine for PDU (sorry for the comments which are in German) so you can get the idea.

it takes some time until everything works as supposed ...

Sorry, but you need login in to view this attachment

polarized

Joined: 13 May 2002
Posts: 74
Location: Europe

22 May 2003 16:43 microcontroller to tc35i

Hi,

What is the easiest way of finding out the actual SMS message lenght. I do not need all of the parameters like the origin number, time stamp etc.. The only thing from the PDU sequence I need would be the actual message composed from ascii characters. I know that the characters are located on the right side of the PDU sequence. How can you calculate the data lenght by examing the PDU sequence?

Regards.

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

22 May 2003 17:08 siemens a35 commands

In theory it works like this:

You start having the complete PDU in a buffer (the pdu must already be in binary format that means "AABBCCDDEE" must equal to 0xAA, 0xBB, 0xCC, 0xDD, 0xEE).

Start by reading the first byte in the buffer (which is actually length of adress of SMSC) you add 2 to this value and use it as a pointer into the buffer (I assume the buffer starts at offset 0 as is usual in C).

Now the pointer points at lenght of destination adress.

You again read this byte add it to the pointer and finally add 9 (this skips protocol identifier, data coding scheme and timestamp.

Now the pointer must point to the lenght of userdata (which is counted in septets) when reading this value you should have your message lenght.

Please verify if everything is correct, I have only extracted this from my program ...

best regards

kyoko

Joined: 28 Nov 2005
Posts: 9

04 Jan 2006 4:47 program receives nothing from gsm moden

hi, i have buy siemens ME45 data cable and try to get older siemens phones like c35i, s25, s35i r the data cable compatible for all this phones?r this few model support at command?i hav try test siemens C25 with AT command using hyperterminal but i didnt receive any response.

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

04 Jan 2006 8:36 c#+sms+pduconverter+smscaddress

kyoko

it should work (at least with c35 and s35) use 19200 baud 8 bit 1 stop bit no parity no handshake.

best regards

kyoko

Joined: 28 Nov 2005
Posts: 9

11 Jan 2006 1:52 source c tc35i pic

Hi,C-man
at my place i only manage to find siemens M55 it support AT command? and i have the siemens ME45 data cable.
Thanks

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

11 Jan 2006 7:47 what is tc35

kyoko wrote:

Hi,C-man
at my place i only manage to find siemens M55 it support AT command? and i have the siemens ME45 data cable.
Thanks

Yes M55 supports AT commands and also has a "soft modem" built in.

BUT the M45 cable will not work because M55 has the "new" slim lumberg connector (different mechanical size different pinout) ...

best regards

kyoko

Joined: 28 Nov 2005
Posts: 9

22 Jan 2006 8:14 cable pinout tc35

Hi C-man,

I've started using pduspy with Ericsson T28 phone but i still can't get the message sent to my phone. What are the normal settings to send message from PC to the phone?

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

22 Jan 2006 8:51 tc35 cable pinout

Sorry I am not using Ericson phones and I do not know if they support AT commands and PDU format.

Some phones support only AT commands at 115000 baud maybe try this baudrate.

best regards

kyoko

Joined: 28 Nov 2005
Posts: 9

25 Jan 2006 4:16 microcontroller tc35i program

Hi,c-man. I have test the hp with hyperterminal n already know how to send n read sms using it but my problem now is how to program the pic so that it will tell the hp to send sms. Can u give me some example?i using c language wif PICC n using pic16f84. pls help as i newbie at tis area. Thanks a lot

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

25 Jan 2006 6:20 tc35i at command sequence

kyoko,

did you read my posts here in this thread??

You should find everything you need by following the links I gave ...

Also if you want to make life easier for you use 16F628 instead of 16F84 because it has a hardware UART built in.

best regards

kyoko

Joined: 28 Nov 2005
Posts: 9

27 Jan 2006 9:43 septets bit

Hi, c_man. I had tried to find the source code u mention before but i cant find it can u pls give me the links? Thanks a lot. i hav try to write the program using puts[s] and gets[p] and define char s[xx]="at+cmss=1" and so on do u think i in the right path?

chickyMeal

Joined: 24 Jan 2006
Posts: 27

01 Mar 2006 8:38 tc35 gsm software

hi C-man

i'm just starting the same project... to send sms using pic16f877a...
i have siemens a35 rite now... can i use the at commands provided on the link?

to send the at command, can i simply use hyperterminal and send something like
'AT+CGMI' and the phone will reply something...

what about the baud rate settings?

here is the link on siemens at command that i found..

[url]http://www.edaboard.com/viewtopic.php?p=184195#184195 [/url]

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

01 Mar 2006 13:06 tc35i modem and microcontroller

sorry I do not know an A35 Sad

But you can test if your siemens phone supports SMS by using hyperterminal (19200 baud 8 bits 1 stopbit no parity no handshake) and your cable.

Send "AT+CSCS=?" (without the quotes) to the phone and if you receive OK as answer SMS is supported.

Normally "A" types of siemens phones are "stripped down versions" and do not support SMS.

best regards

chickyMeal

Joined: 24 Jan 2006
Posts: 27

07 Mar 2006 1:28 tc35 gsm -gprs

C-man...

what about siemens 3118(at)m50?

C-Man

Joined: 19 Jul 2001
Posts: 1235
Helped: 73

07 Mar 2006 6:12 gsm modem mc35

chickyMeal wrote:

C-man...

what about siemens 3118(at)m50?

M50 sounds OK but try the AT command I have posted above and you will see if it supports SMS

best regards

chickyMeal

Joined: 24 Jan 2006
Posts: 27

07 Mar 2006 7:23 tc35 to pc 3 wire

Alrite thanx C-Man Very Happy

..
The thing is i need to decide which phone to buy...
Prev. i got A35 for free Very Happy

since it does not support sms,
i guess i'll just buy the m50...

marwan naboulsi

Joined: 22 Feb 2006
Posts: 21
Helped: 1

07 Mar 2006 13:09 at+cmms tc35i

hi c-man
it pleasure to contact a person like you
1-what is an at-command
2-waht is an pdu
3-can i interface a pic mcu using ascyncrounus engine with nokia 6110 cellphone or any nokia phone
thank's for all information
best regard
marwan naboulsi

chickyMeal

Joined: 24 Jan 2006
Posts: 27

08 Mar 2006 3:55 tc35 serial connection

Marwan...

It is possible to interface PIC with nokia cellphone...
U can checkouk this site:

http://www.embedtronics.com/nokia/fbus.html#part2

it has a lot of info on how to interface with nokia phone

terka

Joined: 15 Dec 2003
Posts: 102
Helped: 1

08 Mar 2006 5:01 uart pic16f873 error

Men..

Sonyericsson phones works very well about AT command (hayes), like Siemenes phones.....both works on character mode tranfer data (ascii 8 bit) in rs232 and TTL format ( 5 volts)....

I had using ericsson long time ago...konia haves mbus/fbus protocol....dont use it...

Bye

kyoko

Joined: 28 Nov 2005
Posts: 9

13 Mar 2006 2:00 tc35 or tc35i timeout

hi, terka
i had read that u hav done project using ericsson phone so i have some Q to ask u.
i have build a hardware which consist of pic n max232 n the serial connection work using hyperterminal n i hav test T28 with hyperterminal n i have c the response too but the problem is when i connect pic n T28 it didnt show any response so now i in a trouble coz presentation for the project already near i hope that u can give me some advise n can u pls send me the source code that u use to make the hp send sms using pic? thanks a lot i really need u help!!!!