uart rx terminating callback for sim800c

src/it_handlers.c

@@ -130,6 +130,7 @@ void SysTick_Handler(void) {
 
 	srl_keep_timeout(main_kiss_srl_ctx_ptr);
 	srl_keep_timeout(main_wx_srl_ctx_ptr);
+	srl_keep_timeout(main_gsm_srl_ctx_ptr);
 
 	srl_keep_tx_delay(main_wx_srl_ctx_ptr);
 

src/main.c

@@ -897,7 +897,7 @@ int main(int argc, char* argv[]){
    io_ext_watchdog_service();
 
    if (main_config_data_mode->gsm == 1) {
-	   gsm_sim800_init(&main_gsm_state);
+	   gsm_sim800_init(&main_gsm_state, 1);
    }
 
    if (main_config_data_basic-> beacon_at_bootup == 1) {
@@ -976,10 +976,10 @@ int main(int argc, char* argv[]){
 		if (main_config_data_mode->gsm == 1) {
 
 			// if data has been received
-			if (main_gsm_srl_ctx_ptr->srl_rx_state == SRL_RX_DONE || main_kiss_srl_ctx_ptr->srl_rx_state == SRL_RX_ERROR) {
+			if (main_gsm_srl_ctx_ptr->srl_rx_state == SRL_RX_DONE || main_gsm_srl_ctx_ptr->srl_rx_state == SRL_RX_ERROR) {
 
 				// receive callback for communicatio with the modem
-				gsm_sim800_rx_done_callback(main_gsm_srl_ctx_ptr, &main_gsm_state);
+				//gsm_sim800_rx_done_callback(main_gsm_srl_ctx_ptr, &main_gsm_state);
 			}
 		}
 

system/include/drivers/serial.h

@@ -32,6 +32,18 @@
 #define SRL_MODE_ZERO	0
 #define SRL_MODE_DEFLN	1
 
+#define SRL_NO_START_CHR	0
+#define SRL_NO_STOP_CHR		0
+
+#define SRL_ECHO_ENABLE		1
+#define SRL_ECHO_DISABLE	0
+
+/**
+ * Callback definition which may be called after receiving each byte by an UART
+ *
+ * @param current_data	received byte
+ * @param rx_bytes_counter receive bytes counter incremented AFTER this callback is processed so it's point to the byte which triggered this call
+ */
 typedef uint8_t(*srl_rx_termination_callback_t)(uint8_t current_data, const uint8_t * const rx_buffer, uint16_t rx_bytes_counter);
 
 typedef enum srlRxState {

system/include/gsm/sim800c.h

@@ -19,9 +19,9 @@ typedef enum gsm_sim800_state_t {
 	SIM800_GPRS_CONNECTED
 }gsm_sim800_state_t;
 
-void gsm_sim800_init(gsm_sim800_state_t * state);
+void gsm_sim800_init(gsm_sim800_state_t * state, uint8_t enable_echo);
 
 void gsm_sim800_pool(srl_context_t * srl_context, gsm_sim800_state_t * state);
-void gsm_sim800_rx_done_callback(srl_context_t * srl_context, gsm_sim800_state_t * state);
+uint8_t gsm_sim800_rx_callback(uint8_t current_data, const uint8_t * const rx_buffer, uint16_t rx_bytes_counter);	// callback used to detect echo
 
 #endif /* INCLUDE_GSM_SIM800C_H_ */

system/src/gsm/sim800c.c

@@ -11,12 +11,25 @@
 
 #include <string.h>
 
-static const char * AUTOBAUD_STRING = "AT\r\n\0";
+static const char * AUTOBAUD_STRING = "AT\r\0";
 static const char * OK = "OK\0";
 
 uint32_t gsm_time_of_last_command_send_to_module = 0;
 
-void gsm_sim800_init(gsm_sim800_state_t * state) {
+// let's the library know if gsm module echoes every AT command send through serial port
+uint8_t gsm_at_comm_echo = 1;
+
+// used to receive echo and response separately
+uint8_t gsm_receive_newline_counter = 0;
+
+// first character of non-echo response from the module
+uint16_t gsm_response_start_idx = 0;
+
+void gsm_sim800_init(gsm_sim800_state_t * state, uint8_t enable_echo) {
+
+	gsm_at_comm_echo = enable_echo;
+
+	gsm_response_start_idx = 0;
 
 	if (state != 0x00) {
 		*state = SIM800_NOT_YET_COMM;
@@ -26,6 +39,10 @@ void gsm_sim800_init(gsm_sim800_state_t * state) {
 void gsm_sim800_pool(srl_context_t * srl_context, gsm_sim800_state_t * state) {
 
 	if (*state == SIM800_NOT_YET_COMM) {
+
+		// configure rx timeout
+		srl_switch_timeout(srl_context, 1, 0);
+
 		// send handshake
 		srl_send_data(srl_context, (const uint8_t*) AUTOBAUD_STRING, SRL_MODE_ZERO, strlen(AUTOBAUD_STRING), SRL_INTERNAL);
 
@@ -36,7 +53,8 @@ void gsm_sim800_pool(srl_context_t * srl_context, gsm_sim800_state_t * state) {
 		srl_wait_for_tx_completion(srl_context);
 
 		// start data reception
-		srl_receive_data(srl_context, 4, 0, '\r', 0, 0, 0);
+		//srl_receive_data(srl_context, 8, SRL_NO_START_CHR, SRL_NO_STOP_CHR, SRL_ECHO_DISABLE, 0, 0);
+		srl_receive_data_with_callback(srl_context, gsm_sim800_rx_callback);
 
 		// record when the handshake has been sent
 		gsm_time_of_last_command_send_to_module = main_get_master_time();
@@ -46,12 +64,35 @@ void gsm_sim800_pool(srl_context_t * srl_context, gsm_sim800_state_t * state) {
 /**
  * Callback to be called just after the reception is done
  */
-void gsm_sim800_rx_done_callback(srl_context_t * srl_context, gsm_sim800_state_t * state) {
+uint8_t gsm_sim800_rx_callback(uint8_t current_data, const uint8_t * const rx_buffer, uint16_t rx_bytes_counter) {
 
-	int response_compare_res = 123;
+	char current = (char) current_data;
 
-	if (state == SIM800_INITIALIZIG) {
-		// compare the response from the module
-		response_compare_res = strcmp(OK, srl_context->srl_rx_buf_pointer);
+	char before = '\0';
+
+	if (rx_bytes_counter > 0) {
+		before = (char) *(rx_buffer + rx_bytes_counter - 1);
 	}
+
+	// check what character has been received
+	if (current == '\n') {
+		// increase newline counter
+		gsm_receive_newline_counter++;
+	}
+
+	// check if this is first character of response
+	if (current != '\n' && current != '\r' && (before == '\n' || before == '\r')) {
+		gsm_response_start_idx = rx_bytes_counter;
+	}
+
+	// if an echo is enabled and second newline has been received
+	if (gsm_at_comm_echo == 1 && gsm_receive_newline_counter > 1 && gsm_response_start_idx > 0) {
+
+		gsm_receive_newline_counter = 0;
+
+		return 1;
+	}
+
+	return 0;
+
 }