Option to not clearing cache after sending data to Thingspeak.com (#1369)

README.md

@@ -4,9 +4,9 @@ ESPurna ("spark" in Catalan) is a custom firmware for ESP8285/ESP8266 based smar
 It uses the Arduino Core for ESP8266 framework and a number of 3rd party libraries.
 
 [![version](https://img.shields.io/badge/version-1.13.3-brightgreen.svg)](CHANGELOG.md)
-[![branch](https://img.shields.io/badge/branch-sensors-orange.svg)](https://github.com/xoseperez/espurna/tree/sensors/)
+[![branch](https://img.shields.io/badge/branch-dev-orange.svg)](https://github.com/xoseperez/espurna/tree/dev/)
 [![license](https://img.shields.io/github/license/xoseperez/espurna.svg)](LICENSE)
-[![travis](https://travis-ci.org/xoseperez/espurna.svg?branch=sensors)](https://travis-ci.org/xoseperez/espurna)
+[![travis](https://travis-ci.org/xoseperez/espurna.svg?branch=dev)](https://travis-ci.org/xoseperez/espurna)
 [![codacy](https://api.codacy.com/project/badge/Grade/c9496e25cf07434cba786b462cb15f49)](https://www.codacy.com/app/xoseperez/espurna/dashboard)
 [![downloads](https://img.shields.io/github/downloads/xoseperez/espurna/total.svg)](https://github.com/xoseperez/espurna/releases)
 <br />

code/espurna/config/general.h

@@ -1005,6 +1005,11 @@
 #define THINGSPEAK_APIKEY           ""              // Default API KEY
 #endif
 
+#ifndef THINGSPEAK_CLEAR_CACHE
+#define THINGSPEAK_CLEAR_CACHE      1               // Clear cache after sending values
+                                                    // Not clearing it will result in latest values for each field being sent every time
+#endif
+
 #define THINGSPEAK_USE_ASYNC        1               // Use AsyncClient instead of WiFiClientSecure
 
 // THINGSPEAK OVER SSL

code/espurna/thinkspeak.ino

@@ -25,6 +25,8 @@ const char THINGSPEAK_REQUEST_TEMPLATE[] PROGMEM =
     "%s\r\n";
 
 bool _tspk_enabled = false;
+bool _tspk_clear = false;
+
 char * _tspk_queue[THINGSPEAK_FIELDS] = {NULL};
 
 bool _tspk_flush = false;
@@ -45,6 +47,7 @@ void _tspkWebSocketOnSend(JsonObject& root) {
 
     root["tspkEnabled"] = getSetting("tspkEnabled", THINGSPEAK_ENABLED).toInt() == 1;
     root["tspkKey"] = getSetting("tspkKey");
+    root["tspkClear"] = getSetting("tspkClear", THINGSPEAK_CLEAR_CACHE).toInt() == 1;
 
     JsonArray& relays = root.createNestedArray("tspkRelays");
     for (byte i=0; i<relayCount(); i++) {
@@ -71,6 +74,7 @@ void _tspkWebSocketOnSend(JsonObject& root) {
 #endif
 
 void _tspkConfigure() {
+    _tspk_clear = getSetting("tspkClear", THINGSPEAK_CLEAR_CACHE).toInt() == 1;
     _tspk_enabled = getSetting("tspkEnabled", THINGSPEAK_ENABLED).toInt() == 1;
     if (_tspk_enabled && (getSetting("tspkKey").length() == 0)) {
         _tspk_enabled = false;
@@ -221,10 +225,12 @@ void _tspkEnqueue(unsigned char index, char * payload) {
 }
 
 void _tspkClearQueue() {
-    for (unsigned char id=0; id<THINGSPEAK_FIELDS; id++) {
-        if (_tspk_queue[id] != NULL) {
-            free(_tspk_queue[id]);
-            _tspk_queue[id] = NULL;
+    if (_tspk_clear) {
+        for (unsigned char id=0; id<THINGSPEAK_FIELDS; id++) {
+            if (_tspk_queue[id] != NULL) {
+                free(_tspk_queue[id]);
+                _tspk_queue[id] = NULL;
+            }
         }
     }
 }
@@ -250,6 +256,7 @@ void _tspkFlush() {
     }
 
 }
+
 // -----------------------------------------------------------------------------
 
 bool tspkEnqueueRelay(unsigned char index, unsigned char status) {

code/html/index.html

@@ -1086,9 +1086,21 @@
                                     <div class="pure-u-1 pure-u-lg-1-4"><input type="checkbox" name="tspkEnabled" tabindex="30" /></div>
                                 </div>
 
+                                <div class="pure-g">
+                                    <label class="pure-u-1 pure-u-lg-1-4">Clear cache</label>
+                                    <div class="pure-u-1 pure-u-lg-1-4"><input type="checkbox" name="tspkClear" tabindex="31" /></div>
+                                    <div class="pure-u-0 pure-u-lg-1-2"></div>
+                                    <div class="pure-u-0 pure-u-lg-1-4"></div>
+                                    <div class="pure-u-1 pure-u-lg-3-4 hint">
+                                        With every POST to thinkspeak.com only enqueued fields are sent. 
+                                        If you select to clear the cache after every sending this will result in only those fields that have changed will be posted.
+                                        If you want all fields to be sent with every POST do not clear the cache.
+                                    </div>
+                                </div>
+
                                 <div class="pure-g">
                                     <label class="pure-u-1 pure-u-lg-1-4">Thingspeak API Key</label>
-                                    <input class="pure-u-1 pure-u-lg-3-4" name="tspkKey" type="text" tabindex="31" />
+                                    <input class="pure-u-1 pure-u-lg-3-4" name="tspkKey" type="text" tabindex="32" />
                                 </div>
 
                                 <legend>Sensors &amp; actuators</legend>