From fce306f7fe4b449fd10652da3f0f275f7d6d1741 Mon Sep 17 00:00:00 2001
From: Hendrik Langer <hendrik+dev@xd0.de>
Date: Mon, 26 Mar 2018 15:25:18 +0200
Subject: [PATCH] prevent delays > powerbankInterval

---
 src/main.cpp | 77 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 43 insertions(+), 34 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index c6a0088..f942395 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -74,6 +74,7 @@ DHT dht(DHT22_PIN, DHTTYPE);
 SDS011 sds;
 volatile unsigned long geiger_counts = 0;
 unsigned long geiger_previousMillis;
+unsigned long last_wifi_activity = 0;
 
 struct __attribute__((packed)) SENSOR_DATA {
   float temperature;
@@ -88,6 +89,42 @@ struct __attribute__((packed)) SENSOR_DATA {
   float rssi;
 } sd;
 
+
+void sendESPNOW() {
+  unsigned long espnowmillis = millis();
+  uint8_t remoteMac[] = {0x5C, 0xCF, 0x7F, 0x5, 0xFD, 0xF0};
+  #define WIFI_CHANNEL 1
+
+  WiFi.forceSleepWake();
+  delay(1);  // yield();
+  digitalWrite(LED_BUILTIN, LOW);
+  WiFi.persistent(false); // don't load and save credentials to flash
+  WiFi.mode(WIFI_STA);
+  if (esp_now_init()==0) {
+    if(esp_now_set_self_role(ESP_NOW_ROLE_CONTROLLER)==0){
+
+      esp_now_add_peer(remoteMac, ESP_NOW_ROLE_SLAVE, WIFI_CHANNEL, NULL, 0);
+      u8 bs[sizeof(sd)];
+      memcpy(bs, &sd, sizeof(sd));
+      for (int i=0; i<20; i++)
+        esp_now_send(NULL, bs, sizeof(sd)); // max ESP_NOW_MAX_DATA_LEN
+
+    } else {
+      Serial.println("error configuring ESP NOW");
+    }
+  } else {
+    Serial.println("error initializing ESP NOW");
+  }
+  last_wifi_activity = millis();
+  esp_now_deinit();
+  WiFi.mode(WIFI_OFF);
+  WiFi.forceSleepBegin();
+  delay(1); // yield();
+  digitalWrite(LED_BUILTIN, HIGH);
+//  Serial.printf("sendESPNOW() took %d ms\n", millis()-espnowmillis);
+}
+
+
 void ICACHE_FLASH_ATTR sendValues() {
   sd.temperature = dht.readTemperature();
   sd.humidity = dht.readHumidity();
@@ -178,16 +215,18 @@ void ICACHE_FLASH_ATTR sendValues() {
   wifiMulti.addAP("LNet", "password2");
   wifiMulti.addAP("Freifunk", "");
   int tries = 0;
+  constexpr unsigned int retry_delay = 500;
   while (wifiMulti.run() != WL_CONNECTED) {
     tries++;
     Serial.print(".");
-    if (tries > 20) {
+    if (tries*retry_delay >= powerbankInterval) {
       Serial.println(" [ERROR]");
       Serial.println("Retrying in 10 seconds..");
+      sendESPNOW();
       delay(powerbankInterval);
       ESP.restart();
     }
-    delay(500);
+    delay(retry_delay);
   }
   Serial.println(" [CONNECTED]");
   Serial.print("IP address: ");
@@ -218,6 +257,7 @@ void ICACHE_FLASH_ATTR sendValues() {
 
   }
 
+  last_wifi_activity = millis();
   WiFi.disconnect();
   WiFi.mode(WIFI_OFF);
   WiFi.forceSleepBegin();
@@ -225,38 +265,6 @@ void ICACHE_FLASH_ATTR sendValues() {
 
 }
 
-void sendESPNOW() {
-  unsigned long espnowmillis = millis();
-  uint8_t remoteMac[] = {0x5C, 0xCF, 0x7F, 0x5, 0xFD, 0xF0};
-  #define WIFI_CHANNEL 1
-
-  WiFi.forceSleepWake();
-  delay(1);  // yield();
-  digitalWrite(LED_BUILTIN, LOW);
-  WiFi.persistent(false); // don't load and save credentials to flash
-  WiFi.mode(WIFI_STA);
-  if (esp_now_init()==0) {
-    if(esp_now_set_self_role(ESP_NOW_ROLE_CONTROLLER)==0){
-
-      esp_now_add_peer(remoteMac, ESP_NOW_ROLE_SLAVE, WIFI_CHANNEL, NULL, 0);
-      u8 bs[sizeof(sd)];
-      memcpy(bs, &sd, sizeof(sd));
-      for (int i=0; i<20; i++)
-        esp_now_send(NULL, bs, sizeof(sd)); // max ESP_NOW_MAX_DATA_LEN
-
-    } else {
-      Serial.println("error configuring ESP NOW");
-    }
-  } else {
-    Serial.println("error initializing ESP NOW");
-  }
-  esp_now_deinit();
-  WiFi.mode(WIFI_OFF);
-  WiFi.forceSleepBegin();
-  delay(1); // yield();
-  digitalWrite(LED_BUILTIN, HIGH);
-//  Serial.printf("sendESPNOW() took %d ms\n", millis()-espnowmillis);
-}
 
 void ICACHE_RAM_ATTR ISR_geiger_impulse() {
   geiger_counts++;
@@ -287,6 +295,7 @@ void setup() {
 
 void loop() {
   sendValues();
+
   /* keep powerbank happy */
   for(int i=0; i<(postingInterval/powerbankInterval)-1; i++) {
     delay(powerbankInterval);