Tauno Erik

Special letters

Animals, birds and other interesting things

Artist Hans Haggenberg. About 1488.

Depiction of women in heraldry

St. Gall Abbot Ulrich Rösch’s (1462-1491) book of heraldry, containing 1,626 coats of arms of prominent people from the laity and the clergy, mostly from the southern region of Germany. This heraldic book was probably prepared in the Heidelberg workshop of Hans Ingeram for an unknown customer from the area between the Neckar River and the Upper Rhine. In the 1480s St. Gall Abbot Ulrich Rösch purchased the volume and had numerous coats of arms from Swiss and German border areas added in the back pages; these were drawn by Winterthur artist Hans Haggenberg. One of the most important heraldic record books of the 15th century.

Link: https://www.e-codices.unifr.ch/en/csg/1084/bindingA/0/Sequence-729

Cave

White ship

My home environment and air quality monitoring system

We often hide the electronics in a box. And cases can be done well and nicely. But when our main interest is electronics then it is sad to hide it. That is way like to do it the opposite way.

Sensors will measure particulate matter (Ultrafine dust PM2.5 and fine dust PM10), co2, TVOC, ambient light, humidity, temperature and barometric pressure.

Most sensors use I2C to communicate. That makes it super easy to build.

Why and what

We spend much of our lives indoors. And that is why it is important that our main living environment is healthy.

CO2 level should be less than <1000 ppm
TVOC is the concentration of Volatile organic compounds (VOCs) present in the air. Should be less than <100 ppm.
PM2.5 refers to atmospheric particulate matter (PM) that have a diameter of less than 2.5 micrometres. The 24-hour concentration of PM2.5 is considered unhealthy when it rises above 35.4 (60) μg/m3.
PM10 refers to atmospheric particulate matter (PM) that have a diameter of less than 10 micrometres. < 100 μg/m3.
Humidity 40-60 %
Temperature 21-25 °C

Code

Code can be found on the GitHub repository.

Schematics

This is the basic schematics.

Because I still had free pins, I added four LEDs.

My power supply is 9V. This is a circuit to make 3.3C and 5V what my MCU and sensors need.

Data

There are four places to view real-time data:

On display
Via serial monitor
Local webpage
ThingSpeak channel. Publick view: https://thingspeak.com/channels/1099844

In the long term, all data is stored on the ThingSpeak channel.

Display view:

Serial Monitor view:

Simple local website:

ThingSpeak view:

Notes

First, test all sensors separately to make sure they all work properly.
There are different libraries. Test them to be sure they will work with your MCU and sensor.
Keep code modular. So you can easily add and remove sections.
Wear gloves. The wires may become hot during soldering.

Main board: WeMos D1 mini (ESP8266)

3.3V
Link to the store: https://www.digitspace.com/d1-mini-node-mcu-lua-wifi-esp-12f-esp8266?2e40f3ca70399010
Pinout reference

Default I2C SDA/SCL pins:

D2 – GPIO4 – SDA
D1 – GPIO5 – SCL

BMP280 Humidity, temperature, barometric pressure and altitude sensor

I2C Address: 0x76 or 0x77
Link to the store: https://www.digitspace.com/gy-bmp280-3-3-high-precision-atmospheric-sensor-module?2e40f3ca70399010
Library: https://github.com/adafruit/Adafruit_BMP280_Library

Pins

BMP280	ESP8266
VCC	3V3
GND	GND
SCL	D1
SDA	D2
CSE	–
SDD	–

APDS-9960 Proximity, RGB and gesture sensor

I2C Address: 0x39
ambient light
colour measuring
proximity detection
touchless gesture. Operating range 10-20cm.

Pins

APDS9960	ESP8266
VIN	3V3
GND	GND
SCL	D1
SDA	D2
INT	–

Library

It works when you comment out //_wire.end();
https://github.com/arduino-libraries/Arduino_APDS9960

CCS-811 (CJMCU-811) Digital gas sensor monitoring indoor air quality

I2C Address: 0x5A or 0x5B
Needs pull-up resistors
eCO2
eTVOCs

Pins

CCS811	ESP8266
VCC	3V3
GND	GND
SDA	D2
SCL	D1
nWAKE	D3 or GND
INT	–
RST	–
ADD	–

Library

Update sensor firmware: https://github.com/maarten-pennings/CCS811/tree/master/examples/ccs811flash

1.3″ Oled display module 128×64

Unknown manufacturer. After trial and error, I discovered my display driver is SH1106. Not SSD1306 like Adafruit uses. But when I use SH1106 constructor:

U8X8_SH1106_128X64_NONAME_HW_I2C display (/* reset=*/ U8X8_PIN_NONE);

Display will look good. But the AM2320 sensor will not work for unknown reason. I2C communication problem?
That’s why I still use SSD1306 constructor. The fonts do not look nice and on the screen right side has white scratched strip.

U8X8_SSD1306_128X64_NONAME_SW_I2C display(/* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);

Link to the store: https://www.digitspace.com/1-3-oled-display-module-128-64-i2c?2e40f3ca70399010

Pins

OLED	ESP8266
GND	GND
VCC	5V
SCL	D1
SDA	D2

Library

AM2320 Temperature and humidity sensor

I2C Address: 0x5C
Link to the store: https://www.digitspace.com/am2320-digital-temperature-humidity-sensor-module-for-arduino?2e40f3ca70399010

Sensor will work normally a couple of hours. After that will not respond anymore. Needs power off restart.

Pins

AM2320	ESP8266
GND	GND
VCC	3V3
SDA	D2
SCL	D1

Library

https://github.com/EngDial/AM2320
https://github.com/adafruit/Adafruit_AM2320 (works 2h then returns nan)

Nova PM SDS011 Dust sensor

Can measure fine dust and smoke = particulate matter (MP) concentrations in two categories:

Ultrafine dust particles with a diameter of 0 – 2.5 micrometres (μm/m3). Output PM2.5
Fine dust particles with a diameter 2.5 – 10 micrometres (μm/m3). Output PM10
RX UART data (3.3V)
TX UART data (3.3V)
Link to the store: https://www.digitspace.com/sds011-air-quality-sensor-module?2e40f3ca70399010
Library: https://github.com/lewapek/sds-dust-sensors-arduino-library

Pins

SDS011	ESP8266
TXD	D7
RXD	D8
GND	GND
25um	–
5V	5V
1um	–
NC	–

Park bench

Dust sensor

Nova PM sensor SDS011 can measure fine dust and smoke = particulate matter (MP) concentrations in two categories:

Ultrafine dust particles with a diameter of 0 – 2.5 micrometres (μm/m3). Output PM2.5
Fine dust particles with a diameter 2.5 – 10 micrometres (μm/m3). Output PM10

The sensor is designed with a built-in fan to ensure sample air circulation to a chamber with a laser diode, where the size and amount of PMis determined. The scattered light is transformed into electrical signals and with further analysis, on the signal waveform, the digital output of the component is the particle concentration of PM2.5 andPM10 (from counts of particles with diameters from 0.3 to 10μm). The working principle is based on light scattering, where a light source illuminates the particles and the scattered light is transformed into a signal by a photodetector, the amplitude of which depends on the light wavelength, scattering angle, particle size and relative index of refraction between medium and particle. (3)

Hardware

SDS011 package includes sensor, cable and serial adapter module (USB to TTL). I got mine here: https://www.digitspace.com/sds011-air-quality-sensor-module?2e40f3ca70399010

And I use ESP8266 (Wemos D1 mini) to connect to sensor.

Sensor input voltage 5V. ESP8266 uses 3.3V. Sensor RX and TX pins are 3.3V tolerant.

Sensor have UART (Serial) output.

Its service life is up to 8000 hours. It is less than a year. So it’s better when sensor will not work all the time. And you make measurement from time to time. Like every ten minutes.

The sensor have more pins but we only need RX, TX, 5V and GND. Other can be left disconnected.

We have to disconnect sensor TX and RX pins to upload new firmware. So maybe is better to add toggle switches between these pins.

Software

I use Nova Fitness SDS dust sensors arduino library. It works well with ESP8266 and uses Software serial.

I chose D3 and D4 pins to connect to sensor.

#include <Arduino.h>
#include <SdsDustSensor.h>

/* SDS011 Dust Sensor */
const int SDS_RX_PIN = D3; // D3 -> SDS011 TX pin
const int SDS_TX_PIN = D4; // D4 -> SDS011 TX pin
SoftwareSerial softwareSerial(SDS_RX_PIN, SDS_TX_PIN);
SdsDustSensor sds(softwareSerial); //  additional parameters: retryDelayMs and maxRetriesNotAvailable

const int MINUTE = 60000;
const int WAKEUP_WORKING_TIME = 30000; // 30 seconds.
const int MEASUREMENT_INTERVAL = 5 * MINUTE;

void setup() {
  Serial.begin(115200);

  Serial.println("SDS011 dust sensor");
  delay(MINUTE);

  /* SDS011 Dust Sensor */
  sds.begin();
  // Prints SDS011 firmware version:
  Serial.print("SDS011 ");
  Serial.println(sds.queryFirmwareVersion().toString()); 
  // Ensures SDS011 is in 'query' reporting mode:
  Serial.println(sds.setQueryReportingMode().toString()); 
}

void loop() {

  // Wake up SDS011
  sds.wakeup();
  delay(WAKEUP_WORKING_TIME);

  // Get data from SDS011
  PmResult pm = sds.queryPm();
  if (pm.isOk()) {
    Serial.print("PM2.5 = ");
    Serial.print(pm.pm25); // float, μg/m3

    Serial.print(", PM10 = ");
    Serial.println(pm.pm10);

  } else {
    Serial.print("Could not read values from sensor, reason: ");
    Serial.println(pm.statusToString());
  }

  // Put SDS011 back to sleep
  WorkingStateResult state = sds.sleep();
  if (state.isWorking()) {
    Serial.println("Problem with sleeping the SDS011 sensor.");
  } else {
    Serial.println("SDS011 sensor is sleeping");
    delay(MEASUREMENT_INTERVAL);
  }
}

And my sensor output: