TC35i GSM With PIC 16F690 help
Hi
Can someone help me please providing a schematic to link up my PIC with TC35i GSM modem.
I have seen an schematic provided by Aratti, linking TC35i with 16F873.
What I would like to ask is why MAX232 is used? What does this IC actually do and why not to connect the PIC directly to the TC35i?
Damien
Re: TC35i GSM With PIC 16F690 help
hi all,
I have read through the discussion that you guys had. They are so informative and useful. Now I want to send message to the PIC16f690 to turn on a LED. My GSM and PIC can work well with hyperterminal. However, if i want to have a direct connection from GSM to PIC, i dont get any response. Any ideas?
char AT[]={0x41,0x54,0x2B,0x43,0x4D,0x47,0x52,0x3D,0x34,0x0 D,0x0A}; //AT+CMGR=1
while(1)
{
for (j=0;j<11;j++)
{
TXREG=AT[j];
for (i=0;i<500;i++){
}
}
if (RCREG=='T') // if receive T then turn on LED
{
PORTC=0x01;
}
for (i=0;i<1000;i++){
}
}
Re: TC35i GSM With PIC 16F690 help
Quote:
I have read through the discussion that you guys had
And did you notice that we are using BASIC ?
Re: TC35i GSM With PIC 16F690 help
Yes I knew it. Though it's BASIC but I still get some ideas from it. So do you have any ideas for C?:)
Re: TC35i GSM With PIC 16F690 help
After a long time, but I would like to ask here as well as you lot have worked with TC35i:
* Are there any AT commands for this or how to see the keyed in number from the mobile keypad on the other end during an active voice call. MY TC35i is connected to my comp with RS232. I am watching and sending normal AT commands using hyperterminal.
Currently what happens is that I dial the modem using my mobile, hyperterminal shows RING ****, I send ATA, and call gets answered and OK appears. After that when I press any number on the keypad, nothing appears on the hyperterminal.
Hope to crack this problem here soon. Thanks
Re: TC35i GSM With PIC 16F690 help
Numbers are encoded in the DTMF signal. If you need to read them you have to decode the dtmf sound signal. The easiest way is to use a MT8880.
Cheers
Al.
Re: TC35i GSM With PIC 16F690 help
Thanks Al. Though I will search on this IC now, but I am a little confused as to the connections of this IC. What I mean is I have used TX/RX lines from RS232 already, where would this DTMF IN/OUT will connect to? I have come across few circuits but this IC is connected to home phone line rather than MODEMS.
Re: TC35i GSM With PIC 16F690 help
The DTFNM input that normally is connected to the phone line, must be connected to the voice out of your TC35i. Generally one capacitor of 100 nF and 100 Khoms in series is just enough. See the examples on the data sheet. The decoding is presented as a nibble ( 4 bits).
Cheers
Al.
Re: TC35i GSM With PIC 16F690 help
Moved from Schematics.
Robert