receive & read sms

[planet69]

a project involving SIM300 and a PIC processor which both parties communicating via USART.
my immediate thought on to process incoming sms text (SIM300 text mode) is to store each ASCII into a temporary buffer.
But the problem is that a complete sms text (includes time, date, tel. number as well as the message) use up to 80-100 RAM buffer.
that is a lot of RAM space to put aside. 
any better suggestion?   

[alspa]

Planet69,

If you don't need to process the SMS message then you can just display the message on LCD or pass to commuter via serial port.

If you need to analyse it then you do not need to store the entire message, just scan through the message as it arrives and look for key letters/words.

If you really need to store the sms message than get a serial eeprom. 1Mbit is about $2

Cheers,
Alspa

[ambo]

I'm only a hobbyist and not a good programmer.  I saw alot of sms based mcu projects.  Most of the the ones that uses small ram are simple controllers.  For AT-command based, a full sms text based will use about 211 bytes of ram.  You can also use pdu method instead of ascii to save more ram.  For Nokia phones, you could use fbus protocol.

For me, since I'm only a hobbyist who is not good at programming, I decided to us a pic18f2685 or a pic18f4680.  Lots of ram, eeprom and program space to compensate for my not so efficient coding style.

[ric_vas]

If you have a full USART connection you can try something with RTS/CTS flow control and work with small buffers...of course it will depend on what kind of information you need to extract from the received SMS.

Ric

[Kombinator]

First, for sending SMS:
1.create buffer for text.
2 Second buffer for coding to PDU (ASCII from 0 to 127___ 1-bit is not used)
3.Create Structore OCTETS (CSA,Destination Adres,UDL and PDU mesages.
4.Coding all HEX  to ASCII and send to UART ......