don't crash, pressure compensation, remove battery

src/main.cpp

@@ -41,7 +41,7 @@ constexpr unsigned int dhcp_interval = 60*60*1000;
 
 uint32_t loop_count = 0;
 
-#define EXTERNAL_POWER 1
+//#define EXTERNAL_POWER 1
 
 //senseBox ID
 #define SENSEBOX_ID "5a9e9e38f55bff001a494877"
@@ -80,6 +80,8 @@ static constexpr uint8_t GEIGER_PIN = D6;
 static constexpr float CONV_FACTOR = 0.008120;
 static constexpr float OWN_BACKGROUND_CPS = 0.2;  // documentation says 0.2 (make sure value doesn't get negative if subtracting!)
 
+static constexpr float HEIGHT = 142;
+
 #ifndef EXTERNAL_POWER
 ADC_MODE(ADC_VCC);
 #endif
@@ -148,6 +150,11 @@ void inline lightsleep() {
 void ICACHE_FLASH_ATTR getValuesJSON(char* buffer, const size_t buf_len, int format) {
   StaticJsonDocument<MQTT_MAX_PACKET_SIZE> jsonDoc;  // ToDo: buf_len
 
+  // https://de.wikipedia.org/wiki/Barometrische_H%C3%B6henformel#Reduktion_auf_Meeresh%C3%B6he
+  // https://carnotcycle.wordpress.com/2012/08/04/how-to-convert-relative-humidity-to-absolute-humidity/
+  float absolute_humidity = (6.112*exp((17.67*sd.temperature)/(sd.temperature+243.5))*(sd.humidity/100)*18.02)/((273.15+sd.temperature)*1000*0.08314);
+  float pressure_compensation_factor = exp((9.80665/(287.05*(sd.temperature+273.15+0.12*(((absolute_humidity*461.5*(sd.temperature+273.15))/100)/100)+0.0065*(HEIGHT/2))))*HEIGHT);
+
   if (format == 1) {
     JsonArray array = jsonDoc.to<JsonArray>();
 
@@ -162,7 +169,7 @@ void ICACHE_FLASH_ATTR getValuesJSON(char* buffer, const size_t buf_len, int for
     pressureObject["value"] = sd.pressure;
     JsonObject pressureObject2 = array.createNestedObject();
     pressureObject2["sensor"] = SENSOR3_ID;
-    pressureObject2["value"] = sd.pressure+16;
+    pressureObject2["value"] = sd.pressure*pressure_compensation_factor;
     if (sd.sds_updated) {
       JsonObject pm10Object = array.createNestedObject();
       pm10Object["sensor"] = SENSOR4_ID;
@@ -192,7 +199,7 @@ void ICACHE_FLASH_ATTR getValuesJSON(char* buffer, const size_t buf_len, int for
 
     jsonDoc["temperature"] = sd.temperature;
     jsonDoc["humidity"] = sd.humidity;
-    jsonDoc["pressure"] = sd.pressure;
+    jsonDoc["pressure"] = sd.pressure*pressure_compensation_factor;
     if (sd.sds_updated) {
       jsonDoc["pm10"] = sd.p10;
       jsonDoc["pm2.5"] = sd.p25;
@@ -290,7 +297,7 @@ void ICACHE_FLASH_ATTR sendValues() {
     }
     DEBUG_MSG(" [CONNECTED, static]\n");
     DEBUG_MSG("IP address: ");
-    DEBUG_MSG("%s\n", String(WiFi.localIP()).c_str());
+    DEBUG_MSG("%s\n", WiFi.localIP().toString().c_str());
 
   } else {
     DEBUG_MSG("dhcp\n");
@@ -309,7 +316,7 @@ void ICACHE_FLASH_ATTR sendValues() {
     }
     DEBUG_MSG(" [CONNECTED, dhcp]\n");
     DEBUG_MSG("IP address: ");
-    DEBUG_MSG("%s\n", String(WiFi.localIP()).c_str());
+    DEBUG_MSG("%s\n", WiFi.localIP().toString().c_str());
 
     ip = WiFi.localIP();
     dns = WiFi.dnsIP();
@@ -355,6 +362,7 @@ void ICACHE_FLASH_ATTR sendValues() {
   net.setInsecure();
   mqttclient.begin(mqttserver, 8883, net);
   int tries = 0;
+  bool mqtt_error = false;
   constexpr unsigned int retry_delay = 500;
   constexpr unsigned int max_retry_delay = 5000;
   while (!mqttclient.connect(mqttusername, mqttusername, mqttpassword)) {
@@ -364,19 +372,24 @@ void ICACHE_FLASH_ATTR sendValues() {
       DEBUG_MSG(" [ERROR]\n");
       //DEBUG_MSG("Rebooting..\n");
       //ESP.restart();
+      mqtt_error = true;
     }
     delay(retry_delay);
   }
 
-  mqttclient.loop();
-  getValuesJSON(buffer, MQTT_MAX_PACKET_SIZE, 2);
-  if (mqttclient.publish("sensor/esp-weatherstation/01/json", buffer, strlen(buffer))) {
-    DEBUG_MSG("mqtt done\n");
-  } else {
-    DEBUG_MSG("mqtt failed\n");
+  if (!mqtt_error) {
+
+    mqttclient.loop();
+    getValuesJSON(buffer, MQTT_MAX_PACKET_SIZE, 2);
+    if (mqttclient.publish("sensor/esp-weatherstation/01/json", buffer, strlen(buffer))) {
+      DEBUG_MSG("mqtt done\n");
+    } else {
+      DEBUG_MSG("mqtt failed\n");
+    }
+    mqttclient.loop();
+    mqttclient.disconnect();
+
   }
-  mqttclient.loop();
-  mqttclient.disconnect();
 
   if (sd.rssi == 0) {  // re-read rssi if zero
     sd.rssi = WiFi.RSSI();

src/main.h

@@ -7,6 +7,6 @@
   #define DEBUG_MSG(...)
 #endif
 
-#define FW_VERSION 30
+#define FW_VERSION 34
 
 #endif /* _MAIN_H */