v6.0 increase batterylife

New default to low energy mode with a smart algorithm to only measure CO2, if the temperature changed by more than 0.5°C or the humidity by 2% or 5 minutes passed. Increase battery runtime to up to 11 weeks.

Bugfix: LED color fixed on HWSubRev < 3

Also USB updates are only enabeled if the OpenCO2 Sensor is plugged in already on the first boot.

Author: davidkreidler

OpenCO2_Sensor.ino

@@ -10,13 +10,12 @@
    - WiFiManager: https://github.com/tzapu/WiFiManager
    - ArduinoMqttClient (if MQTT is defined)
 */
-#define VERSION "v5.9"
+#define VERSION "v6.0"
 
 #define HEIGHT_ABOVE_SEA_LEVEL 50             // Berlin
 #define TZ_DATA "CET-1CEST,M3.5.0,M10.5.0/3"  // Europe/Berlin time zone from https://github.com/nayarsystems/posix_tz_db/blob/master/zones.csv
 #define LIGHT_SLEEP_TIME 500
 #define DEEP_SLEEP_TIME 29124             // 30 sec
-#define LOW_ENERGY_DEEP_SLEEP_TIME 287924 // 5 min
 #define DEEP_SLEEP_TIME_NO_DISPLAY_UPDATE DEEP_SLEEP_TIME + 965 // offset for no display update
 static unsigned long lastMeasurementTimeMs = 0;
 
@@ -77,19 +76,13 @@ CRGB leds[1];
 #include <Wire.h>
 SensirionI2cScd4x scd4x;
 
-
-#ifndef ARDUINO_USB_MODE
-#error This ESP32 SoC has no Native USB interface
-#elif ARDUINO_USB_MODE == 1
-#error This sketch should be used when USB is in OTG mode and MSC On Boot enabled
-#endif
 #include "USB.h"
-#include <USBMSC.h>
-USBMSC usbmsc;
+#include "FirmwareMSC.h"
+FirmwareMSC MSC_Update;
 
 RTC_DATA_ATTR bool USB_ACTIVE = false, initDone = false, BatteryMode = false, comingFromDeepSleep = false;
-RTC_DATA_ATTR bool LEDonBattery, LEDonUSB, useSmoothLEDcolor, invertDisplay, useFahrenheit, useWiFi, lowEnergyMode, english, limitMaxBattery;
-RTC_DATA_ATTR uint8_t ledbrightness, HWSubRev, font;
+RTC_DATA_ATTR bool LEDonBattery, LEDonUSB, useSmoothLEDcolor, invertDisplay, useFahrenheit, useWiFi, english, limitMaxBattery;
+RTC_DATA_ATTR uint8_t ledbrightness, HWSubRev, font, skipMeasurement = 10;
 RTC_DATA_ATTR float maxBatteryVoltage;
 
 /* TEST_MODE */
@@ -327,8 +320,7 @@ float getTempOffset() {
     if (useWiFi) return 12.2;
     return 4.4;
   } else {
-    if (lowEnergyMode) return 0.0;
-    return 0.8;
+    return 0.0; // was with periodic measurment 0.8
   }
 }
 
@@ -348,7 +340,7 @@ void initOnce() {
     if (HWSubRev < 3) {
       Wire.begin(33, 34);  // green, yellow
       digitalWrite(LED_POWER, LOW);   // LED on
-      FastLED.addLeds<APA102, 40, 39, RGB>(leds, 1);
+      FastLED.addLeds<APA102, 40, 39, BGR>(leds, 1);
     } else {
       Wire.begin(3, 2);
       digitalWrite(LED_POWER, HIGH);  // LED on
@@ -370,7 +362,6 @@ void initOnce() {
   preferences.begin("co2-sensor", true);
   maxBatteryVoltage = preferences.getFloat("MBV", 3.95);
   useWiFi = preferences.getBool("WiFi", false);
-  lowEnergyMode = preferences.getBool("lowEnergy", false);
   LEDonBattery = preferences.getBool("LEDonBattery", false);
   LEDonUSB = preferences.getBool("LEDonUSB", true);
   ledbrightness = preferences.getInt("ledbrightness", 5);
@@ -389,7 +380,7 @@ void initOnce() {
   scd4x.setSensorAltitude(HEIGHT_ABOVE_SEA_LEVEL);
   scd4x.setAutomaticSelfCalibrationEnabled(1); // Or use setAutomaticSelfCalibrationTarget if needed
   scd4x.setTemperatureOffset(getTempOffset());
-  if (!(BatteryMode && lowEnergyMode)) scd4x.startPeriodicMeasurement();
+  if (!BatteryMode) scd4x.startPeriodicMeasurement();
 
   displayInit();
   delay(3000);  // Wait for co2 measurement
@@ -594,6 +585,9 @@ void calibrate() {
   /* Only run this, if calibration is needed!
    let the Sensor run outside for 3+ minutes before.
  */
+  scd4x.stopPeriodicMeasurement();
+  scd4x.wakeUp();
+  scd4x.startLowPowerPeriodicMeasurement();
   displayCalibrationWarning();
   delay(500);
   for (int i = 0; i < 180; i++) {
@@ -789,15 +783,13 @@ void setup() {
   /* scd4x */
   if (HWSubRev < 3) {
     Wire.begin(33, 34);  // green, yellow
-    FastLED.addLeds<APA102, 40, 39, RGB>(leds, 1);
+    FastLED.addLeds<APA102, 40, 39, BGR>(leds, 1);
   } else {
     Wire.begin(3, 2);
     FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, 1);
   }
   scd4x.begin(Wire, 0x62); // 0x62 is the default I2C address for SCD4x
 
-  USB.onEvent(usbEventCallback);
-  usbmsc.isWritable(true);
   if (!initDone) initOnce();
 
 #if ARDUINO_USB_CDC_ON_BOOT && !ARDUINO_USB_MODE
@@ -826,11 +818,17 @@ void setup() {
   }
 
   if (useWiFi && !BatteryMode) startWiFi();
+
+  if (!BatteryMode && !comingFromDeepSleep) {
+    USB.onEvent(usbEventCallback);
+    MSC_Update.begin();
+    USB.begin();
+  }
 }
 
 
 void loop() {
-  if ((!useWiFi || (lowEnergyMode && BatteryMode)) && esp_sleep_get_wakeup_cause() == ESP_SLEEP_WAKEUP_GPIO) handleButtonPress();
+  if ((!useWiFi || BatteryMode) && esp_sleep_get_wakeup_cause() == ESP_SLEEP_WAKEUP_GPIO) handleButtonPress();
   updateBatteryMode();  // check again in USB Power mode
   updateCharging();
   measureESP32temperature();
@@ -856,7 +854,7 @@ void loop() {
     goto_light_sleep(5000 - (millis() - lastMeasurementTimeMs));
   }
 
-  if (!(BatteryMode && lowEnergyMode) && !TEST_MODE) {
+  if (!BatteryMode && !TEST_MODE) {
     bool isDataReady = false;
     uint16_t ready_error = scd4x.getDataReadyStatus(isDataReady);
     if (ready_error || !isDataReady) {
@@ -870,11 +868,27 @@ void loop() {
   uint16_t new_co2 = 420;
   float new_temperature = 0.0f;
   uint16_t error;
-  if (BatteryMode && lowEnergyMode) {
-    scd4x.stopPeriodicMeasurement();
+  if (BatteryMode) {
+    if (!comingFromDeepSleep) scd4x.stopPeriodicMeasurement();
     scd4x.wakeUp();
     scd4x.setTemperatureOffset(getTempOffset());
-    //delay(10);
+
+    /* check if temp/humidity changed */
+    scd4x.measureSingleShotRhtOnly();
+    uint16_t dummyCo2; // CO2 output is returned as 0 ppm
+    float new_humidity = 0.0f;
+    error = scd4x.readMeasurement(dummyCo2, new_temperature, new_humidity);
+    if (!error
+    && (skipMeasurement > 1) 
+    && (fabs(new_temperature - temperature) < 0.5)
+    && (fabs(new_humidity - humidity) < 2.0)) {
+      scd4x.powerDown();
+      skipMeasurement--;
+      saveMeasurement(co2, new_temperature, new_humidity);
+      goto_deep_sleep(DEEP_SLEEP_TIME_NO_DISPLAY_UPDATE);
+    }
+    skipMeasurement = 10; // force update every 5 minutes
+
     if (HWSubRev < 3) scd4x.measureSingleShot(); // Ignore first measurement after wake up.
     error = scd4x.measureAndReadSingleShot(new_co2, new_temperature, humidity);
     scd4x.powerDown();
@@ -895,19 +909,12 @@ void loop() {
     extern uint16_t refreshes;
     if (BatteryMode || (refreshes % 6 == 1)) {
       saveMeasurement(new_co2, new_temperature, humidity);
-
-      if (BatteryMode && lowEnergyMode) { // fill measurements of past 5 min
-        for (int i=0; i<9; i++) {
-          saveMeasurement(new_co2, new_temperature, humidity);
-        }
-      }
     }
 
     /* don't update in Battery mode, unless CO2 has changed by 4% or temperature by 0.5°C */
     if (!TEST_MODE && BatteryMode && comingFromDeepSleep) {
       if ((abs(new_co2 - co2) < (0.04 * co2)) && (fabs(new_temperature - temperature) < 0.5)) {
-        if (lowEnergyMode) goto_deep_sleep(LOW_ENERGY_DEEP_SLEEP_TIME);
-        else               goto_deep_sleep(DEEP_SLEEP_TIME_NO_DISPLAY_UPDATE);
+        goto_deep_sleep(DEEP_SLEEP_TIME_NO_DISPLAY_UPDATE);
       }
     }
 
@@ -957,11 +964,11 @@ void loop() {
   if (BatteryMode) {
     if (!comingFromDeepSleep) {
       scd4x.stopPeriodicMeasurement();
-      scd4x.setTemperatureOffset(getTempOffset());
-      if (!lowEnergyMode) scd4x.startLowPowerPeriodicMeasurement();
+      MSC_Update.end();
+      USB_ACTIVE = false;
+      delay(100);
     }
-    if (lowEnergyMode) goto_deep_sleep(LOW_ENERGY_DEEP_SLEEP_TIME);
-    else               goto_deep_sleep(DEEP_SLEEP_TIME);
+    goto_deep_sleep(DEEP_SLEEP_TIME);
   }
 
   goto_light_sleep(LIGHT_SLEEP_TIME);

README.md

@@ -8,7 +8,7 @@ OpenCO2 Sensor is an Arduino IDE compatible Repository for an E-Ink Indoor air q
 
 ## Buy it [here on Tindie](https://www.tindie.com/products/davidkreidler/open-co2-sensor/)
 
-Especially in winter, when windows are closed, a reminder to ventilate regularly is useful for health, comfort and well-being. Poor indoor air quality can lead to decreased productivity and learning disabilities. Therefore, I developed an Open-source ESP32 project that uses an E-Ink display and a LED to show the indoor CO2 content. Take the small Sensor anywhere you go to monitor the Air Quality, with Battery life of 11+ days.
+Especially in winter, when windows are closed, a reminder to ventilate regularly is useful for health, comfort and well-being. Poor indoor air quality can lead to decreased productivity and learning disabilities. Therefore, I developed an Open-source ESP32 project that uses an E-Ink display and a LED to show the indoor CO2 content. Take the small Sensor anywhere you go to monitor the Air Quality, with Battery life of up to 11 weeks.
 
 # CO2 Sensor
 

epd_abstraction.h

@@ -22,7 +22,6 @@ enum LEDMenuOptions {
   NUM_LED_OPTIONS
 };
 enum DisplayMenuOptions {
-  UPDATE,
   MAX_BATTERY,
   INVERT,
   TEMP_UNIT,
@@ -57,7 +56,6 @@ const char* EnglishLEDmenuItems[NUM_LED_OPTIONS] = {
   "Exit"
 };
 const char* EnglishOptionsMenuItems[NUM_DISPLAY_OPTIONS] = {
-  "Update",
   "Battery",
   "Invert",
   "Unit",
@@ -90,7 +88,6 @@ const char* GermanLEDmenuItems[NUM_LED_OPTIONS] = {
   "Beenden"
 };
 const char* GermanOptionsMenuItems[NUM_DISPLAY_OPTIONS] = {
-  "Update",
   "Battery",
   "Invert",
   "Einheit",

epd_abstraction.ino

@@ -210,18 +210,6 @@ void OptionsMenu() {
       }
       if (mspressed > 1000) { // long press
         switch (selectedOption) {
-          case UPDATE:
-            lowEnergyMode = !lowEnergyMode;
-            preferences.begin("co2-sensor", false);
-            preferences.putBool("lowEnergy", lowEnergyMode);
-            preferences.end();
-
-            if (BatteryMode) {
-              scd4x.stopPeriodicMeasurement();
-              scd4x.setTemperatureOffset(getTempOffset());
-              if (!lowEnergyMode) scd4x.startPeriodicMeasurement();
-            }
-            break;
           case MAX_BATTERY:
             toggleMaxBattery();
             break;
@@ -806,15 +794,13 @@ void displayOptionsMenu(uint8_t selectedOption) {
     else         OptionsMenuItem = GermanOptionsMenuItems[i];
     Paint_DrawString_EN(5, 25*(i+1), OptionsMenuItem, &Font24, WHITE, BLACK);
   }
-  if (lowEnergyMode) Paint_DrawString_EN(200-17*4, 25, "5min", &Font24, WHITE, BLACK);
-  else Paint_DrawString_EN(200-17*5, 25, "30sec", &Font24, WHITE, BLACK);
 
-  if (limitMaxBattery  && HWSubRev > 2) Paint_DrawString_EN(200-17*4, 25*2, "~80%", &Font24, WHITE, BLACK);
-  else Paint_DrawString_EN(200-17*4, 25*2, "100%", &Font24, WHITE, BLACK);
+  if (limitMaxBattery  && HWSubRev > 2) Paint_DrawString_EN(200-17*4, 25, "~80%", &Font24, WHITE, BLACK);
+  else Paint_DrawString_EN(200-17*4, 25, "100%", &Font24, WHITE, BLACK);
 
-  Paint_DrawString_EN(166, 25*4, (useFahrenheit? "*F":"*C"), &Font24, WHITE, BLACK);
-  Paint_DrawNum(149, 25*6, (int32_t)(font+1), &Font24, BLACK, WHITE);
-  Paint_DrawString_EN(166, 25*6, "/2", &Font24, WHITE, BLACK);
+  Paint_DrawString_EN(166, 25*3, (useFahrenheit? "*F":"*C"), &Font24, WHITE, BLACK);
+  Paint_DrawNum(149, 25*5, (int32_t)(font+1), &Font24, BLACK, WHITE);
+  Paint_DrawString_EN(166, 25*5, "/2", &Font24, WHITE, BLACK);
 
   invertSelected(selectedOption);
   updateDisplay();
@@ -1252,7 +1238,6 @@ void displayinfo() {
   delay(10);
   scd4x.getTemperatureOffset(tOffset);
   if (!BatteryMode) scd4x.startPeriodicMeasurement();
-  else if (!lowEnergyMode) scd4x.startLowPowerPeriodicMeasurement();
   Paint_DrawString_EN(1, 145, "T_offset:", &Font16, WHITE, BLACK);
   char offset[20];
   snprintf(offset, sizeof(offset), "%.2f", tOffset);
@@ -1336,15 +1321,6 @@ void displayBattery(uint8_t percentage) {
       BlackImage[y+x*25] = ~BlackImage[y+x*25];
     }
   }
-
-  /* low Energy Mode */
-  if (lowEnergyMode) {
-    Paint_DrawRectangle(97, 13, 115, 47, BLACK, DOT_PIXEL_2X2, DRAW_FILL_EMPTY); //case
-    Paint_DrawLine(103, 10, 109, 10, BLACK, DOT_PIXEL_3X3, LINE_STYLE_SOLID);//nippel
-    Paint_DrawLine(106, 25, 106, 35, BLACK, DOT_PIXEL_2X2, LINE_STYLE_SOLID);//+
-    Paint_DrawLine(102, 30, 110, 30, BLACK, DOT_PIXEL_2X2, LINE_STYLE_SOLID);//+
-    //Xstart, Ystart, Xend, Yend
-  }
 #endif /* EINK_1IN54V2 */
 
 #ifdef EINK_4IN2