SIM900 stm32 interfacing problem.

Posted on March 27, 2014 at 23:29

I am working on SIM900 stm32 interfacing.

Firstly, I communicated SIM900 with computer, using hyperterminal. It is succesfull, so GSM module is OK.  I removed echo messages permamently, and setted baudrate to 9600, It is also permamently. I saved this setting with AT&W command

now. I want to communicate with stm32. It is also working, but receiving data writen false on LCD.  I think, This is delay problem. I tried all combination of delay, but still same problem 

My GSM modem is http://gsmkontrol.blogspot.com.tr/

MY board is STM3210Ceval board

they are communicating via rs232

some part of my codes.

while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);

USART_SendData(USART2, 65);  // A

while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);

USART_SendData(USART2, 84); // T

while(USART_GetFlagStatus(USART2, USART_FLAG_TXE) == RESET);

USART_SendData(USART2, 13);   // CR

while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET);

re[0] = USART_ReceiveData(USART2);

while(USART_GetFlagStatus(USART2, USART_FLAG_RXNE) == RESET);

re[1] = USART_ReceiveData(USART2);

LCD_DisplayStringLine(Line5,re);

#think!