v4.6 history graph and README update

Go to Menu -> History to see up to 18h of CO2 or Temperature/Humidity measurements in a graph. Min/max/avg values will also be displayed. QR code order is inverted now for easier export.

Author: davidkreidler

OpenCO2_Sensor.ino

@@ -10,7 +10,7 @@
    - WiFiManager: https://github.com/tzapu/WiFiManager
    - ArduinoMqttClient (if MQTT is defined)
 */
-#define VERSION "v4.5"
+#define VERSION "v4.6"
 
 #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
@@ -84,7 +84,7 @@ SensirionI2CScd4x scd4x;
 
 RTC_DATA_ATTR bool USB_ACTIVE = false, initDone = false, BatteryMode = false, comingFromDeepSleep = false;
 RTC_DATA_ATTR bool LEDonBattery, LEDonUSB, useSmoothLEDcolor, invertDisplay, useFahrenheit, useWiFi, english;
-RTC_DATA_ATTR int ledbrightness, HWSubRev, font;
+RTC_DATA_ATTR uint8_t ledbrightness, HWSubRev, font;
 RTC_DATA_ATTR float maxBatteryVoltage;
 
 /* TEST_MODE */
@@ -484,51 +484,24 @@ void rainbowMode() {
 
 RTC_DATA_ATTR uint8_t hour = 0;
 RTC_DATA_ATTR uint8_t halfminute = 0;
-RTC_DATA_ATTR uint16_t measurements[24][120];
-void saveMeasurement(uint16_t co2) {
+#define NUM_HOURS 16 // ESP32-S2 slow RTC memory limitation
+RTC_DATA_ATTR SensorData measurements[NUM_HOURS][120];
+void saveMeasurement(uint16_t co2, float temperature, float humidity) {
   if (halfminute == 120) {
     halfminute=0;
     hour++;
   }
-  if (hour == 24) {
-    for (int i=0; i<23; ++i) memcpy(measurements[i], measurements[i + 1], sizeof(uint16_t) * 120);
-    hour = 23;
+  if (hour == NUM_HOURS) {
+    for (int i=0; i<NUM_HOURS-1; ++i) memcpy(measurements[i], measurements[i + 1], sizeof(SensorData) * 120);  // destination, source
+    hour = NUM_HOURS-1;
   }
 
-  measurements[hour][halfminute] = co2;
+  measurements[hour][halfminute].co2 = co2;
+  measurements[hour][halfminute].temperature = (uint16_t)temperature*10;
+  measurements[hour][halfminute].humidity = (uint8_t)humidity;
   halfminute++;
 }
 
-uint8_t qrcodeNumber = 0;
-void history() {
-  // DEMO DATA:
-  /*hour = 2;
-  for (int i=0; i<120; i++) {
-    measurements[0][i] = 400+i;
-    measurements[1][i] = 520+i;
-    measurements[2][i] = 1000+i;
-  }
-  halfminute = 120;*/
-
-  if (halfminute == 0 && hour == 0) { // no history data
-    displayNoHistory();
-    unsigned long StartTime = millis();
-    for (;;) if ((millis() - StartTime) > 20000 || digitalRead(BUTTON) == 0) return; // wait for button press OR up to 20 sec
-  }
-
-  qrcodeNumber = hour; // start at current hour
-  for (int i=0; i<200; i++) {
-    if (digitalRead(BUTTON) == 0) {  // goto next qr code
-      displayHistory(measurements);
-      delay(500);
-      if (qrcodeNumber == hour) qrcodeNumber = 0;
-      else qrcodeNumber++;
-      i = 0; // display qrcode again for 20 sec
-    }
-    delay(100);
-  }
-}
-
 void handleWiFiChange() {
   scd4x.stopPeriodicMeasurement();
   scd4x.setTemperatureOffset(getTempOffset());
@@ -612,7 +585,7 @@ void startWiFi() {
 float currentTemp = temperatureRead();
 RTC_DATA_ATTR float ESP32temps[10] = {currentTemp,currentTemp,currentTemp,currentTemp,currentTemp,currentTemp,currentTemp,currentTemp,currentTemp,currentTemp};
 RTC_DATA_ATTR float sumTemp = currentTemp * 10;
-RTC_DATA_ATTR int indexTemp = 0;
+RTC_DATA_ATTR uint8_t indexTemp = 0;
 void measureESP32temperature() {
   currentTemp = temperatureRead();
   sumTemp -= ESP32temps[indexTemp];
@@ -694,7 +667,8 @@ void loop() {
     errorToString(error, errorMessage, 256);
     displayWriteError(errorMessage);
   } else {
-    if (BatteryMode) saveMeasurement(new_co2);
+    extern int refreshes;
+    if (BatteryMode || (refreshes%6 == 1)) saveMeasurement(new_co2, new_temperature, humidity);
     /* don't update in Battery mode, unless CO2 has changed by 3% or temperature by 0.5°C */
     if (!TEST_MODE && BatteryMode && comingFromDeepSleep) {
       if ((abs(new_co2 - co2) < (0.03*co2)) && (fabs(new_temperature - temperature) < 0.5)) {

README.md

@@ -4,7 +4,7 @@
 
 ![alt text](https://github.com/davidkreidler/OpenCO2_Sensor/raw/main/pictures/Header.png)
 
-OpenCO2 Sensor is an Arduino IDE compatible Repository for an E-Ink Indoor air quality Sensor using the ESP32, SCD4X and an RBG LED.
+OpenCO2 Sensor is an Arduino IDE compatible Repository for an E-Ink Indoor air quality Sensor using the ESP32, SCD4X and an RGB LED.
 
 ## Buy it [here on Tindie](https://www.tindie.com/products/davidkreidler/open-co2-sensor/)
 
@@ -41,30 +41,37 @@ Size: 4.7 x 4.1 x 2.4 cm
 # Menu
 
 Press the Menu button on the backside of the OpenCO2 Sensor. Select an option via long press (1+ sec) or move to next menu point via a short press. Choose between:
-* `LED toggle` enable or disable the LED in battery mode
-* `Rainbow` fun little easter egg (press ↪️ to exit)
+* `LED` control color, brightness and when the LED should be enabled
+* `Display` can be inverted. Also change the Temperature unit, language and font
 * `Calibrate` put the sensor outside for 3+ minutes (only run this, if calibration is needed)
-* `History` display up to 24 QR codes containing 1h of measurements each (only stored in battery mode)
+* `History` display up to 18h of CO2, temperature and humidity as a graph. Values can also be exported via QR codes containing 1h of CO2 measurements each.
 * `Wi-Fi` enable or disable wireless connections
-* `Exit` quit Menu (automatically after 20 sec)
+* `Info` shows MAC Address, serial numbers, uptime, version and battery details
+* `Rainbow` fun little easter egg
 
 # Wi-Fi
 
-Enable Wi-Fi via the Menu button. When power is connected, an access point `OpenCO2 Sensor` is enabled. Connect to it and navigate to http://192.168.4.1 (it will open automatically on modern Smartphones). Insert your home Wi-Fi credentials under `Configure WiFi`. Choose your network name from the list in the top and insert the password. Click `Save`. The sensor will now be automatically connected. Navigate to ip:9925 to see current co2/temperature/humidity measurements.
+Enable Wi-Fi via the Menu button. When power is connected, an access point `OpenCO2 Sensor` is enabled. Connect to it and navigate to http://192.168.4.1 (it will open automatically on modern Smartphones). Insert your home Wi-Fi credentials under `Configure WiFi`. Choose your network name from the list in the top and insert the password. Click `Save`. The sensor will now be automatically connected. Navigate to IP:9925 to see current co2/temperature/humidity measurements.
 ![alt text](https://github.com/davidkreidler/OpenCO2_Sensor/raw/main/pictures/setup.jpg)
 
 # AirGradient / Grafana
 
 Use [internet-pi](https://github.com/geerlingguy/internet-pi) to store the CO2 / Temperature / Humidity data on your Pi. First connect the OpenCO2 Sensor to your Wi-Fi network and follow the instructions https://www.youtube.com/watch?v=Cmr5VNALRAg Then download the https://raw.githubusercontent.com/davidkreidler/OpenCO2_Sensor/main/grafana_OpenCO2_Sensor.json and import it into Grafana.
 ![alt text](https://github.com/davidkreidler/OpenCO2_Sensor/raw/main/pictures/grafana.png)
 
+# Update via USB
+
+1. Download `FIRMWARE.BIN` from the latest [release](https://github.com/davidkreidler/OpenCO2_Sensor/releases)
+2. Plug a data USB-C cable into your PC and the Sensor
+3. copy `FIRMWARE.BIN` to the USB device
+
 # OTA Update
 
-Download `OpenCO2_Sensor.ino.bin` from the latest [release](https://github.com/davidkreidler/OpenCO2_Sensor/releases).
+Download `FIRMWARE.BIN` from the latest [release](https://github.com/davidkreidler/OpenCO2_Sensor/releases).
 Enable Wi-Fi via the Menu button, in an area where no previously known network is active. Connect power. Then connect to `OpenCO2 Sensor` and navigate to http://192.168.4.1 . Under `Update` select the `OpenCO2_Sensor.ino.bin` file and click `Update`. The Sensor will restart.
 ![alt text](https://github.com/davidkreidler/OpenCO2_Sensor/raw/main/pictures/OTA.jpg)
 
-# Update via USB
+# Update via USB (from an old release)
 
 1. Download all files from the latest [release](https://github.com/davidkreidler/OpenCO2_Sensor/releases)
 2. Make sure, that the power switch is in the `ON` position (down)

epd_abstraction.h

@@ -80,6 +80,12 @@ const char* GermanOptionsMenuItems[NUM_DISPLAY_OPTIONS] = {
   "Beenden"
 };
 
+typedef struct {
+    uint8_t humidity : 7;      // 7 bits (range 0 to 100)
+    uint16_t temperature : 9;  // 9 bits (/10= range 0 to 51.1°C )
+    uint16_t co2;
+} SensorData;
+
 void handleButtonPress();
 void changeFont(int font);
 void displayWelcome();
@@ -93,8 +99,6 @@ void displayWriteTestResults(float voltage, uint16_t sensorStatus);
 void displayBattery(uint8_t percentage);
 void updateDisplay();
 void displayImage(const unsigned char* image_buffer);
-void displayHistory(uint16_t measurements[24][120]);
-void displayNoHistory();
 void displayCalibrationWarning();
 void displayWiFi(bool useWiFi);
 void displayWiFiStrengh();