A6 GSM Module controll from PIC18F MCU
Posted: Thu Sep 01, 2016 2:40 pmCode: Select all
Hi. I have an A6 GSM module that works great via USB to Serial bridge from the laptop. I am able to send and receive text using the three simple following commands:1) AT+CMFG=1 <CR>
2) AT+CMGS="8881234567" <CR> // this is the phone number in the US
3) "the text message goes here$1A" <CR> // CRTL-Z then <CR>
all worked well from the laptop. However, I tried sending the "same" command from the PIC18F microcontroller the three commands above, nothing happens.
Hardware info:
A6 GSM default baud: 115200
PIC18F baud: 115200
Code: Select all
//////////////////////////////////////////////////////////////////
// Setting up: 115200,n,8,1 RS-232 protocol //
// SPBRG = [Fosc/(BAUD*16)] - 1. Current Fosc=8MHz //
// Fosc Baud SPBRG1 //
// 16MHz 9600 103 //
// 8MHz 115200 3 ---> for use with A6 GSM //
// 8MHz 9600 51 //
// 1MHz 9600 5 //
//////////////////////////////////////////////////////////////////
void Init_USART()
{
SPBRG1 = 3; // 115200,n,8,1 at 8HMz
// SPBRG1 = 51; // 9600,n,8,1 at 8MHz
TXSTA1bits.TXEN = 1; // TX enable.
TXSTA1bits.SYNC = 0; // Asynchronous; 8-bit
RCSTA1bits.SPEN = 1; // USART Serial (RC6=TX, RC7=RX) ON
BAUDCONbits.BRG16 = 0; // Baud rate from SYNC=0, BRG16=0, BRHG=1 settings
TXSTA1bits.BRGH = 1; // high speed mode ON
RCSTA1bits.CREN = 1; // continuous receive ON
TRISCbits.TRISC7 = 1; // RX1 USART.
TRISCbits.TRISC6 = 0; // TX1 USART.
PIE1bits.RC1IE = 0; // USART1 RX interrupt OFF.
PIR1bits.RC1IF = 0; // Clear received buffer flag.
}
My only concern now is that I am not terminating the commands correctly.
In C code I have tried sending at the end of each command a 0x0D (carriage return).
When this did not work, I would embed the \r in the command string:
char my_msg[] = "AT+CMGF=1\r";
This did not work also.
When I debugged the code, I did see the correct characters sending out.
Please see attachment and advise. Thank you.