ashutosh121
Newbie level 3
can anyone plz explain the interfacing of GPS and GSM with ATMEGA16
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ashutosh121,
But, give me some more information what you plan to do, how you plan to interface ATmega16 and GSM (for start)? Do you have some development board or something similar? Do you have any schematics to show me, or you just have an idea for project?/*
* Project name:
GSM_Test
* Copyright:
(c) MikroElektronika, 2005-2010.
* Revision History:
20090617:
- initial release;
* Description:
This is a simple project which demonstrates the use of SmartGM862-GPS Board.
Upon programming the MCU, connect your SmartGM862-GPS Board to PORTC of your EasyAVR6 development board.
The goal of this simple example is to display some basic functions of the GSM module like
making and answering a call and hanging up. Note that you'll have to enter the number you wish
to dial to in the atc3 constant.
* Test configuration:
MCU: ATmega16
[url]http://www.atmel.com/dyn/resources/prod_documents/doc2466.pdf[/url]
Dev.Board: EasyAVR6
[url=http://www.mikroe.com/eng/products/view/321/easyavr6-development-system/]EasyAVR6 Development System - AVR Development Board[/url]
Oscillator: External, 8.0000 MHz
Ext. Modules: SmartGM862-GPS Board extra board
[url=http://www.mikroe.com/eng/products/view/469/smartgm862-gps-board/]SmartGM862-GPS Board - Telit GM862-GPS GSM/GPRS development tool - mikroElektronika[/url]
ac:SmartGM862-GPS
SW: mikroC PRO for AVR
[url=http://www.mikroe.com/eng/products/view/228/mikroc-pro-for-avr/]MikroElektronika - mikroC PRO for AVR - C compiler for AVR microcontroller device development[/url]
* NOTES:
- Put the pull-down resistors on the PORTA
- Pull-up resistors on the PD0(Rx) and PD1(Tx) pins, pull-down PB0(RTS)
- In order to connect SmartGM862-GPS to EasyAVR6 dev. board you need to use SmartAdapt2 board:
[url=http://www.mikroe.com/eng/products/view/158/smartadapt2-board/]SmartADAPT2 Board - 16-pin configuration adapter with voltage selection - mikroElektronika[/url]
- SmartGM862-GPS extra board: SW1.3 and SW1.7 ON
*/
// Lcd module connections
sbit LCD_RS at PORTD2_bit;
sbit LCD_EN at PORTD3_bit;
sbit LCD_D4 at PORTD4_bit;
sbit LCD_D5 at PORTD5_bit;
sbit LCD_D6 at PORTD6_bit;
sbit LCD_D7 at PORTD7_bit;
sbit LCD_RS_Direction at DDD2_bit;
sbit LCD_EN_Direction at DDD3_bit;
sbit LCD_D4_Direction at DDD4_bit;
sbit LCD_D5_Direction at DDD5_bit;
sbit LCD_D6_Direction at DDD6_bit;
sbit LCD_D7_Direction at DDD7_bit;
// End Lcd module connections
// set of AT commands
const char atc1[] = "ATE0"; // disable command echo
const char atc2[] = "AT# CAP= 1"; // enables handsfree external mic/ear audio path
const char atc3[] = "ATD123456789;"; // place a call to phone number 123456789
// instead of 123456789 insert your phone number
const char atc4[] = "ATH"; // hang up
const char atc5[] = "ATA"; // answer a call
const char atc6[] = "AT#HFMICG=4"; // handsfree microphone gain
const char atc7[] = "AT#SHFEC=1"; // handsfree echo canceller
const char atc8[] = "AT+CLVL=12"; // loudspeaker volume level
const char atc9[] = "AT#SRS= 3,0"; // select ringer sound
const char atc10[] = "ATS0=0"; // number of rings to auto answer (auto answer disabled)
// lcd interface messages
const LCD_MESSAGE_LENGTH = 16;
const char lcd1[] = "Initializing...";
const char lcd2[] = "Power-Up GSM!!!";
const char lcd3[] = "RA3-Continue";
const char lcd4[] = "Ready! RA0-Dial";
const char lcd5[] = "RA1-HNG RA2-ANSW";
const char lcd6[] = "Calling...";
const char lcd7[] = "Hanging Up!";
const char lcd8[] = "Answering!";
const char lcd9[] = "RING!!!";
// responses to parse
const GSM_OK = 0;
const GSM_RING = 1;
char gsm_state = 0;
char response_rcvd = 0;
short responseID = -1, response = -1;
char msg[LCD_MESSAGE_LENGTH+1];
// copy const to ram string
char * CopyConst2Ram(char * dest, const char * src){
char * d ;
d = dest;
for(;*dest++ = *src++;)
;
return d;
}
// uart rx interrupt handler
void interrupt() org IVT_ADDR_USART_RXC {
char tmp;
tmp = UART1_Read(); // get received byte
// process reception through state machine
// we are parsing only "OK" and "RING" responses
switch (gsm_state) {
case 0: {
response = -1; // clear response
if (tmp == 'O') // we have 'O', it could be "OK"
gsm_state = 1; // expecting 'K'
if (tmp == 'R') // we have 'R', it could be "RING"
gsm_state = 10; // expecting 'I'
break;
}
case 1: {
if (tmp == 'K') { // we have 'K' ->
response = GSM_OK; // we have "OK" response
gsm_state = 50; // expecting CR+LF
}
else
gsm_state = 0; // reset state machine
break;
}
case 10: {
if (tmp == 'I') // we have 'I', it could be "RING"
gsm_state = 11; // expecting 'N'
else
gsm_state = 0; // reset state machine
break;
}
case 11: {
if (tmp == 'N') // we have 'N', it could be "RING"
gsm_state = 12; // expecting 'G'
else
gsm_state = 0; // reset state machine
break;
}
case 12: {
if (tmp == 'G') { // we have 'G' ->
response = GSM_RING; // we have "RING" response
gsm_state = 50; // expecting CR+LF
}
else
gsm_state = 0; // reset state machine
break;
}
case 50: {
if (tmp == 13) // we have 13, it could be CR+LF
gsm_state = 51; // expecting LF
else
gsm_state = 0; // reset state machine
break;
}
case 51: {
if (tmp == 10) { // we have LF, response is complete
response_rcvd = 1; // set reception flag
responseID = response; // set response ID
}
gsm_state = 0; // reset state machine
break;
}
default: { // unwanted character
gsm_state = 0; // reset state machine
break;
}
}
}
// send ATC command
void send_atc(const char *s)
{
// send command string
while(*s) {
UART1_Write(*s++);
}
// terminate command with CR
UART1_Write(0x0D);
}
// get GSM response, if there is any
short get_response() {
if (response_rcvd) {
response_rcvd = 0;
return responseID;
}
else
return -1;
}
// wait for GSM response
void wait_response(char rspns) {
while (get_response() != rspns)
;
}
// pause
void wait() {
Delay_ms(1000);
}
void main() {
// set PORTA inputs
DDA0_bit = 0; // place a call input
DDA1_bit = 0; // hang up input
DDA2_bit = 0; // answer a call input
DDA3_bit = 0; // continue with PIC program
DDB0_bit = 1; // RTS pin
UART1_Init(9600); // initialize USART module
Delay_ms(500);
SREG_I_bit = 1; // enable global interrupt
RXCIE_bit = 1; // enable interrupt on UART receive
// set RTS pin to zero, we will use only RX i TX
PORTB0_bit = 0;
// setup lcd module
Lcd_Init();
Lcd_Cmd(_LCD_CURSOR_OFF);
// LCD_Out: power-up gsm
LCD_Out(1,1,CopyConst2Ram(msg,lcd2));
LCD_Out(2,1,CopyConst2Ram(msg,lcd3));
// wait for start
while(!PINA3_bit)
;
Lcd_Cmd(_LCD_CLEAR);
// LCD_Out: Initializing...
LCD_Out(1,1,CopyConst2Ram(msg,lcd1));
Delay_ms(5000); // wait for the GSM module to initialize it self
// negotiate baud rate
while(1) {
send_atc("AT"); // send "AT" string until gsm sets up its baud rade
Delay_ms(100); // and gets it correctly
if (get_response() == GSM_OK) // if gsm says "OK" on our baud rate we got it
break;
}
// disable command echo
send_atc(atc1);
wait_response(GSM_OK);
// change audio path (enables handsfree external mic/ear audio path)
send_atc(atc2);
wait_response(GSM_OK);
// handsfree microphone gain
send_atc(atc6);
wait_response(GSM_OK);
// handsfree echo canceller
send_atc(atc7);
wait_response(GSM_OK);
// loudspeaker volume level
send_atc(atc8);
wait_response(GSM_OK);
// select ringer sound
send_atc(atc9);
wait_response(GSM_OK);
// number of rings to auto answer (auto answer disabled)
send_atc(atc10);
wait_response(GSM_OK);
while(1) {
// LCD_Out: Ready! RA0-Dial
LCD_Out(1,1,CopyConst2Ram(msg,lcd4));
// LCD_Out: RA1-HNG RA2-ASW
LCD_Out(2,1,CopyConst2Ram(msg,lcd5));
if(Button(&PINA, 0, 10, 1)) {
// LCD_Out: Calling...
Lcd_Cmd(_LCD_CLEAR);
LCD_Out(1,1,CopyConst2Ram(msg,lcd6));
// mobile originated call to specified number
send_atc(atc3);
wait_response(GSM_OK);
}
if(Button(&PINA, 1, 10, 1)) {
// disconnect existing connection
send_atc(atc4);
wait_response(GSM_OK);
Lcd_Cmd(_LCD_CLEAR);
// LCD_Out: Hanging Up!
LCD_Out(1,1,CopyConst2Ram(msg,lcd7));
wait();
}
if(Button(&PINA, 2, 10, 1)) {
// answer a call
send_atc(atc5);
wait_response(GSM_OK);
Lcd_Cmd(_LCD_CLEAR);
// LCD_Out: Answering!
LCD_Out(1,1,CopyConst2Ram(msg,lcd8));
wait();
}
// process gsm response
if (response_rcvd) {
response_rcvd = 0; // clear response received flag
switch (responseID) {
case GSM_OK : break; // do nothing
case GSM_RING : {
// LCD_Out:RING!!!
LCD_Out(1,1,CopyConst2Ram(msg,lcd9));
wait();
}
default : {
// process illegal responses
}
}
}
}
}