Microcontroller › AVR › By using GSM SIM 300M and Atmega8 , How to write coding for sending SMS to 3 Persons when any one the port pin gets high …?
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December 1, 2012 at 5:36 pm #8803AJISH ALFREDParticipant
You’ve connected the speaker output of the APR9600 directly to the MIC input of SIM300. There could be impedance mismatch problems since the speaker output is normally used to drive 8 ohm loudspeaker. Also the speaker output gives signals much stronger than a normal microphone and when the built in amplifier of SIM300 amplifies such high amplitude signals, high signal distortion can happen.
Anyway suggest you to try out the result.
Waiting for your update!
December 3, 2012 at 7:45 am #88065HUJ4ParticipantOk fine i ll update u after testing its out put …..
December 15, 2012 at 7:30 pm #8839ahmed qureshiParticipantPlease help me, i want to send msg via gsm sim900D. I am unable to send txt using this code
#define F_CPU 11059200UL#include <avr/io.h>#include <avr/interrupt.h>#include <stdio.h>#include <stdlib.h>#include “lcd.h”#include <util/delay.h>#include <inttypes.h>#include <string.h>void send_msg();void init_USART();void usart_send_string(char *str );void usart_send(char data);void gsm_cmd(char *cmd);void init_USART(){unsigned int baud=71; //(UBRR= (Fos/ (16*baudrate) )-1 )UBRRH =(unsigned char)(baud>>;UBRRL=(unsigned char)baud;UCSRC|=(1<<URSEL)|(3<<UCSZ0);//Enable The receiver and transmitterUCSRB |= (1<<RXCIE) | (1 << RXEN) | (1 << TXEN); // Turn on the transmission reception .sei();}ISR (USART_RXC_vect){unsigned char value;value = UDR; // Fetch the received byte value into the variable “value”len_recieved++;recieved_msg[len_recieved]=value;if(data_flag==-1)data_flag=0;}}void usart_send_string(char *str ){while((*str)!=’