New improved version of the library which handles the GPRS context more properly.

Author: carrascoacd

Http.cpp

@@ -30,6 +30,7 @@
 
 #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 QUERY_BEARER "AT+SAPBR=2,1\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"
@@ -49,18 +50,22 @@
 #define DOWNLOAD "DOWNLOAD"
 #define HTTP_200 ",200,"
 #define CONNECTED "+CREG: 0,1"
+#define BEARER_OPEN "+SAPBR:1,1"
 
 
 Result HTTP::configureBearer(const char *apn){
 
   Result result = SUCCESS;
 
-  int attempts = 0;
-  int MAX_ATTEMPTS = 10;
+  unsigned int attempts = 0;
+  unsigned int MAX_ATTEMPTS = 10;
+
+  sendATTest();
 
   while (sendCmdAndWaitForResp(REGISTRATION_STATUS, CONNECTED, 2000) != TRUE && attempts < MAX_ATTEMPTS){
     sendCmdAndWaitForResp(SIGNAL_QUALITY, CONNECTED, 1000);
     attempts ++;
+    delay(1000 * attempts);
     if (attempts == MAX_ATTEMPTS) {
       attempts = 0;
       preInit();
@@ -70,7 +75,7 @@ Result HTTP::configureBearer(const char *apn){
   if (sendCmdAndWaitForResp(BEARER_PROFILE_GPRS, OK, 2000) == FALSE)
     result = ERROR_BEARER_PROFILE_GPRS;
 
-  char httpApn[128];
+  char httpApn[64];
   sprintf(httpApn, BEARER_PROFILE_APN, apn);
   if (sendCmdAndWaitForResp(httpApn, OK, 2000) == FALSE)
     result = ERROR_BEARER_PROFILE_APN;
@@ -82,8 +87,10 @@ Result HTTP::connect() {
 
   Result result = SUCCESS;
 
-  if (sendCmdAndWaitForResp(OPEN_GPRS_CONTEXT, OK, 2000) == FALSE){
-    result = ERROR_OPEN_GPRS_CONTEXT;
+  if (sendCmdAndWaitForResp(QUERY_BEARER, BEARER_OPEN, 2000) == FALSE){
+    if (sendCmdAndWaitForResp(OPEN_GPRS_CONTEXT, OK, 6000) == FALSE){
+      result = ERROR_OPEN_GPRS_CONTEXT;
+    }
   }
 
   if (sendCmdAndWaitForResp(HTTP_INIT, OK, 2000) == FALSE)
@@ -109,24 +116,26 @@ Result HTTP::post(const char *uri, const char *body, char *response) {
   Result result = setHTTPSession(uri);
 
   char httpData[32];
-  int delayToDownload = 10000;
-  sprintf(httpData, HTTP_DATA, strlen(body), 2000);
+  unsigned int delayToDownload = 10000;
+  sprintf(httpData, HTTP_DATA, strlen(body), 10000);
   if (sendCmdAndWaitForResp(httpData, DOWNLOAD, 2000) == FALSE){
     result = ERROR_HTTP_DATA;
   }
 
   purgeSerial();
-  printData(body);
-  delay(delayToDownload);
+  delay(500);
+  sendCmd(body);
+  delay(1000);
+
   if (sendCmdAndWaitForResp(HTTP_POST, HTTP_200, delayToDownload) == TRUE) {
     sendCmd(HTTP_READ);
-    result = SUCCESS;
     readResponse(response);
+    result = SUCCESS;
   }
   else {
     result = ERROR_HTTP_POST;
   }
-  
+
   return result;
 }
 

HttpExample/HttpExample.ino

@@ -1,11 +1,9 @@
 #include <ArduinoJson.h>
 #include <Http.h>
 
-HTTP http;
-Result result;
-
 unsigned long lastRunTime = 0;
 unsigned long waitForRunTime = 0;
+HTTP http;
 
 // the setup routine runs once when you press reset:
 void setup() {
@@ -20,52 +18,60 @@ void loop() {
 }
 
 // functions
-void print(const char *message, long result = -1){
-  if (result != -1){
-    char buffer[100];
-    sprintf(buffer, message, result);
-    Serial.println(buffer);
+void print(const __FlashStringHelper *message, int code = -1){
+  if (code != -1){
+    Serial.print(message);
+    Serial.println(code);
   }
   else {
     Serial.println(message);
   }
 }
 
 bool shouldTrackTimeEntry(){
+  // This calculation uses the max value the unsigned long can store as key. Remember when a negative number 
+  // is assigned or the maximun is exceeded, then the module is applied to that value.
   unsigned long elapsedTime = millis() - lastRunTime;
-  print("Elapsed time: %ld", elapsedTime);
+  print(F("Elapsed time: "), elapsedTime);
   return elapsedTime >= waitForRunTime;
 }
 
 void trackTimeEntry(){
 
-  print("Cofigure bearer: %d", http.configureBearer("movistar.es"));
-  print("HTTP connect: %d", http.connect());
-    
-  char response[256];
-  
-  result = http.get("smartgarden.herokuapp.com/api", response);
-  print("HTTP GET: %d", result);
+  char response[32];
+  char body[90];
+  Result result;
+
+  print(F("Cofigure bearer: "), http.configureBearer("movistar.es"));
+  result = http.connect();
+  print(F("HTTP connect: "), result);
+
+  sprintf(body, "{\"name\": \"%s\"}", "Arduino");
+  result = http.post("your.domain/api/devices", body, response);
+  print(F("HTTP POST: "), result);
   if (result == SUCCESS) {
     Serial.println(response);
-    StaticJsonBuffer<200> jsonBuffer;
+    StaticJsonBuffer<32> jsonBuffer;
     JsonObject& root = jsonBuffer.parseObject(response);
     lastRunTime = millis();
     waitForRunTime = root["waitForRunTime"];
 
-    print("Last run time: %ld", lastRunTime);
-    print("Next post in: %ld", waitForRunTime);
+    print(F("Last run time: "), lastRunTime);
+    print(F("Next post in: "), waitForRunTime);
   }
-  
-  result = http.post("smartgarden.herokuapp.com/api", "{\"name\":\"Antonio\"}", response);
-  print("HTTP POST: %d", result);
+
+  result = http.get("your.domain/api/timing", response);
+  print(F("HTTP GET: "), result);
   if (result == SUCCESS) {
     Serial.println(response);
-    StaticJsonBuffer<200> jsonBuffer;
+    StaticJsonBuffer<32> jsonBuffer;
     JsonObject& root = jsonBuffer.parseObject(response);
-    Serial.print("name: ");
-    Serial.println((const char *)root["name"]);
+    lastRunTime = millis();
+    waitForRunTime = root["waitForRunTime"];
+    
+    print(F("Last run time: "), lastRunTime);
+    print(F("Next post in: "), waitForRunTime);
   }
-
-  print("HTTP disconnect: %d", http.disconnect());
+  
+  print(F("HTTP disconnect: "), http.disconnect());
 }

Sim800.cpp

@@ -87,12 +87,6 @@ void SIM800::sendCmd(const char* cmd)
     serialSIM800.write(cmd);
 }
 
-void SIM800::printData(const char* data)
-{
-    Serial.println(data);
-    serialSIM800.print(data);
-}
-
 int SIM800::sendATTest(void)
 {
     int ret = sendCmdAndWaitForResp("AT\r\n","OK",DEFAULT_TIMEOUT);

Sim800.h

@@ -97,11 +97,6 @@ class SIM800
      */
     void sendCmd(const char* cmd);
 
-    /** print data for HTTP POST to SIM800 module
-     *  @param data array which will be send to GPRS module
-     */
-    void printData(const char* data);
-
     /**send "AT" to SIM800 module
      */
     int sendATTest(void);