Improving the consistency and fail tolerance

Author: carrascoacd

Http.cpp

@@ -28,48 +28,61 @@
 #include "Http.h"
 #include <string.h>
 
-const char *BEARER_PROFILE_GPRS = "AT+SAPBR=3,1,\"Contype\",\"GPRS\"\n";
-const char *BEARER_PROFILE_APN = "AT+SAPBR=3,1,\"APN\",\"%s\"\n";
-const char *OPEN_GPRS_CONTEXT = "AT+SAPBR=1,1\n";
-const char *CLOSE_GPRS_CONTEXT = "AT+SAPBR=0,1\n";
-const char *HTTP_INIT = "AT+HTTPINIT\n";
-const char *HTTP_CID = "AT+HTTPPARA=\"CID\",1\n";
-const char *HTTP_PARA = "AT+HTTPPARA=\"URL\",\"%s\"\n";
-const char *HTTP_GET = "AT+HTTPACTION=0\n";
-const char *HTTP_POST = "AT+HTTPACTION=1\n";
-const char *HTTP_DATA = "AT+HTTPDATA=%d,%d\n";
-const char *HTTP_READ = "AT+HTTPREAD\n";
-const char *HTTP_CLOSE = "AT+HTTPTERM\n";
-const char *HTTP_CONTENT = "AT+HTTPPARA=\"CONTENT\",\"application/json\"\n";
-const char *OK = "OK";
-const char *DOWNLOAD = "DOWNLOAD";
-const char *HTTP_200 = ",200,";
+#define BEARER_PROFILE_GPRS "AT+SAPBR=3,1,\"Contype\",\"GPRS\"\r\n"
+#define BEARER_PROFILE_APN "AT+SAPBR=3,1,\"APN\",\"%s\"\r\n"
+#define OPEN_GPRS_CONTEXT "AT+SAPBR=1,1\r\n"
+#define CLOSE_GPRS_CONTEXT "AT+SAPBR=0,1\r\n"
+#define HTTP_INIT "AT+HTTPINIT\r\n"
+#define HTTP_CID "AT+HTTPPARA=\"CID\",1\r\n"
+#define HTTP_PARA "AT+HTTPPARA=\"URL\",\"%s\"\r\n"
+#define HTTP_GET "AT+HTTPACTION=0\r\n"
+#define HTTP_POST "AT+HTTPACTION=1\n"
+#define HTTP_DATA "AT+HTTPDATA=%d,%d\r\n"
+#define HTTP_READ "AT+HTTPREAD\r\n"
+#define HTTP_CLOSE "AT+HTTPTERM\r\n"
+#define HTTP_CONTENT "AT+HTTPPARA=\"CONTENT\",\"application/json\"\r\n"
+#define NORMAL_MODE "AT+CFUN=1,1\r\n"
+#define REGISTRATION_STATUS "AT+CREG?\r\n"
+
+#define OK "OK\r\n"
+#define DOWNLOAD "DOWNLOAD"
+#define HTTP_200 ",200,"
+#define CONNECTED "+CREG: 0,1"
+
 
 Result HTTP::configureBearer(const char *apn){
 
   Result result = SUCCESS;
 
-  if (preInit() == FALSE){
-    result = ERROR_INITIALIZATION;
-  }
-  else{
-    if (sendCmdAndWaitForResp(BEARER_PROFILE_GPRS, OK, 2000) == FALSE)
-      result = ERROR_BEARER_PROFILE_GPRS;
-    
-    char httpApn[128];
-    sprintf(httpApn, BEARER_PROFILE_APN, apn);
-    if (sendCmdAndWaitForResp(httpApn, OK, 2000) == FALSE)
-      result = ERROR_BEARER_PROFILE_APN;
+  int attempts = 0;
+  int MAX_ATTEMPTS = 10;
+  while (sendCmdAndWaitForResp(REGISTRATION_STATUS, CONNECTED, 5000) != TRUE && attempts < MAX_ATTEMPTS){
+    attempts ++;
+    if (attempts == MAX_ATTEMPTS) {
+      attempts = 0;
+      preInit();
+    }
   }
+
+  if (sendCmdAndWaitForResp(BEARER_PROFILE_GPRS, OK, 5000) == FALSE)
+    result = ERROR_BEARER_PROFILE_GPRS;
+  
+  char httpApn[128];
+  sprintf(httpApn, BEARER_PROFILE_APN, apn);
+  if (sendCmdAndWaitForResp(httpApn, OK, 5000) == FALSE)
+    result = ERROR_BEARER_PROFILE_APN;
+  
   return result;
 }
 
 Result HTTP::connect() {
 
   Result result = SUCCESS;
-  if (sendCmdAndWaitForResp(OPEN_GPRS_CONTEXT, OK, 2000) == FALSE)
+
+  if (sendCmdAndWaitForResp(OPEN_GPRS_CONTEXT, OK, 5000) == FALSE)
     result = ERROR_OPEN_GPRS_CONTEXT;
-  if (sendCmdAndWaitForResp(HTTP_INIT, OK, 2000) == FALSE)
+
+  if (sendCmdAndWaitForResp(HTTP_INIT, OK, 5000) == FALSE)
     result = ERROR_HTTP_INIT;
 
   return result;
@@ -78,10 +91,11 @@ Result HTTP::connect() {
 Result HTTP::disconnect() {
 
   Result result = SUCCESS;
-  if (sendCmdAndWaitForResp(HTTP_CLOSE, OK, 2000) == FALSE)
-    result = ERROR_HTTP_CLOSE;
+
   if (sendCmdAndWaitForResp(CLOSE_GPRS_CONTEXT, OK, 2000) == FALSE)
     result = ERROR_CLOSE_GPRS_CONTEXT;
+  if (sendCmdAndWaitForResp(HTTP_CLOSE, OK, 2000) == FALSE)
+    result = ERROR_HTTP_CLOSE;
 
   return result;
 }
@@ -90,9 +104,6 @@ Result HTTP::post(const char *uri, const char *body, char *response) {
 
   Result result = setHTTPSession(uri);
 
-  if (sendCmdAndWaitForResp(HTTP_CONTENT, OK, 5000) == FALSE)
-    result = ERROR_HTTP_CONTENT;
-
   char httpData[128];
   int delayToDownload = 5000;
   sprintf(httpData, HTTP_DATA, strlen(body), delayToDownload);
@@ -101,6 +112,7 @@ Result HTTP::post(const char *uri, const char *body, char *response) {
   }
 
   sendCmd(body);
+  purgeSerial();
   delay(delayToDownload);
 
   if (sendCmdAndWaitForResp(HTTP_POST, HTTP_200, 5000) == TRUE) {
@@ -111,6 +123,8 @@ Result HTTP::post(const char *uri, const char *body, char *response) {
   else {
     result = ERROR_HTTP_POST;
   }
+  
+  return result;
 }
 
 Result HTTP::get(const char *uri, char *response) {
@@ -141,6 +155,9 @@ Result HTTP::setHTTPSession(const char *uri){
   if (sendCmdAndWaitForResp(httpPara, OK, 2000) == FALSE)
     result = ERROR_HTTP_PARA;
 
+  if (sendCmdAndWaitForResp(HTTP_CONTENT, OK, 2000) == FALSE)
+    result = ERROR_HTTP_CONTENT;
+
   return result;
 }
 

Http.h

@@ -29,22 +29,24 @@
 
 /* Result codes */
 enum Result {
-  SUCCESS,
-  ERROR_INITIALIZATION,
-  ERROR_BEARER_PROFILE_GPRS,
-  ERROR_BEARER_PROFILE_APN,
-  ERROR_OPEN_GPRS_CONTEXT,
-  ERROR_QUERY_GPRS_CONTEXT,
-  ERROR_CLOSE_GPRS_CONTEXT,
-  ERROR_HTTP_INIT,
-  ERROR_HTTP_CID,
-  ERROR_HTTP_PARA,
-  ERROR_HTTP_GET,
-  ERROR_HTTP_READ,
-  ERROR_HTTP_CLOSE,
-  ERROR_HTTP_POST,
-  ERROR_HTTP_DATA,
-  ERROR_HTTP_CONTENT
+  SUCCESS = 0,
+  ERROR_INITIALIZATION = 1,
+  ERROR_BEARER_PROFILE_GPRS = 2,
+  ERROR_BEARER_PROFILE_APN = 3,
+  ERROR_OPEN_GPRS_CONTEXT = 4,
+  ERROR_QUERY_GPRS_CONTEXT = 5,
+  ERROR_CLOSE_GPRS_CONTEXT = 6,
+  ERROR_HTTP_INIT = 7,
+  ERROR_HTTP_CID = 8,
+  ERROR_HTTP_PARA = 9,
+  ERROR_HTTP_GET = 10,
+  ERROR_HTTP_READ = 11,
+  ERROR_HTTP_CLOSE = 12,
+  ERROR_HTTP_POST = 13,
+  ERROR_HTTP_DATA = 14,
+  ERROR_HTTP_CONTENT = 15,
+  ERROR_NORMAL_MODE = 16,
+  ERROR_LOW_CONSUMPTION_MODE = 17,
 };
 
 

Readme.md

@@ -1,9 +1,10 @@
 # SIM800L
 A smart library based on Seeeduino that implements the AT HTTP commands to perform GET and POST requests to a JSON API.
-In order to make a requests the library follows these steps:
+In order to perform a request, the library follows these steps:
 
 ##### Configure Bearer:
 
+  - AT+CREG? -> try until 0,1 (connected to the network)
   - AT+SAPBR=3,1,"Contype","GPRS" -> wait for OK
   - AT+SAPBR=3,1,"APN","movistar.es" -> wait for OK
   - AT+SAPBR=1,1 -> wait for OK
@@ -31,3 +32,4 @@ In order to make a requests the library follows these steps:
   - AT+HTTPREAD -> read buffer and parse it
   - AT+HTTPTERM -> wait for OK
   - AT+SAPBR=0,1
+

Sim800.cpp

@@ -30,27 +30,18 @@
 
 int SIM800::preInit(void)
 {
-    pinMode(SIM800_POWER_STATUS,INPUT);
-    delay(10);
-    if(LOW == digitalRead(SIM800_POWER_STATUS))
-    {
-        if(sendATTest() == FALSE)
-        {
-            delay(800);
-            digitalWrite(powerPin,HIGH);
-            delay(200);
-            digitalWrite(powerPin,LOW);
-            delay(2000);
-            digitalWrite(powerPin,HIGH);
-            delay(3000);  
-        }
-        while(sendATTest() == FALSE);             
-        return TRUE;        
-    }
-    else
-    {
-        return FALSE;
-    }
+    pinMode(SIM800_RESET_PIN, OUTPUT);
+
+    digitalWrite(SIM800_RESET_PIN, HIGH);
+    delay(200);
+    digitalWrite(SIM800_RESET_PIN, LOW);
+    delay(2000);
+    digitalWrite(SIM800_RESET_PIN, HIGH);
+    delay(3000);
+
+    purgeSerial();
+    
+    return TRUE;
 }
 
 int SIM800::checkReadable(void)
@@ -112,6 +103,7 @@ int SIM800::waitForResp(const char *resp, unsigned int timeout)
     while(1) {
         if(serialSIM800.available()) {
             char c = serialSIM800.read();
+            Serial.print(c);
             sum = (c==resp[sum]) ? sum+1 : 0;
             if(sum == len)break;
         }
@@ -150,4 +142,9 @@ void SIM800::serialDebug(void)
             serialSIM800.write(Serial.read()); 
         }
     }
+}
+
+void SIM800::purgeSerial()
+{
+  while (serialSIM800.available()) serialSIM800.read();
 }

Sim800.h

@@ -37,8 +37,7 @@
 
 #define SIM800_TX_PIN           8
 #define SIM800_RX_PIN           7
-#define SIM800_POWER_PIN        9
-#define SIM800_POWER_STATUS     12
+#define SIM800_RESET_PIN        12
 
 #define UART_DEBUG
 
@@ -65,8 +64,6 @@ class SIM800
      *  @param baudRate baud rate of uart communication
      */
     SIM800(int baudRate):serialSIM800(SIM800_TX_PIN,SIM800_RX_PIN){
-        powerPin = SIM800_POWER_PIN;
-        pinMode(powerPin,OUTPUT);
         serialSIM800.begin(baudRate);
     };
 
@@ -132,11 +129,12 @@ class SIM800
      */
     void serialDebug(void);
 
-    int powerPin;
-    SoftwareSerial serialSIM800;
+    void purgeSerial();
 
 private:
 
+    SoftwareSerial serialSIM800;
+    
 };
 
 #endif