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|Single address select bit to allow alternate  address to be selected
 
|Single address select bit to allow alternate  address to be selected
 
|}
 
|}
 +
To use the sensor:
 +
 +
# Connect Vcc and Ground
 +
# For a ESP8266, connect SCL and SDA (I2C) to D1 and D2 respectively.
 +
# Connect WAK to ground
 +
 +
Using I2C, the device is on address 0x57.
  
 
===MQ135 Air Quality Sensor===
 
===MQ135 Air Quality Sensor===
 +
This module will return a high signal when the air quality meets a certain criteria.
  
 
===DHT 11, DHT22===
 
===DHT 11, DHT22===
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===MAX30102===
 
===MAX30102===
 
The MAX30102 is a heart rate monitor and pulse oximeter biosensor. These modules cost about $2 USD on AliExpress.
 
The MAX30102 is a heart rate monitor and pulse oximeter biosensor. These modules cost about $2 USD on AliExpress.
 +
 +
Using I2C, this has address 0x5A.
  
 
===HC-SR501 Infrared Motion Sensor===
 
===HC-SR501 Infrared Motion Sensor===

Revision as of 20:08, 26 July 2020

This is a list of sensors and their related information.

MH-Z19 CO2 Sensor

These CO2 modules cost about $17 USD. They come in 3 models: 0-2000PPM, 0-5000PPM, and 0-10000PPM.

Interface: PWM or UART

See: MH-Z19 Carbon Dioxide Sensor

CCS811 Air Quality Sensor

The CCS811 air quality sensor can measure Volatile Organic Compounds (VOCs). These cost about $8 USD.

Pin Number Pin Name Description
1 VCC Power supply for the module can typically 3.3V is used
2 GND Ground of the module, connected to ground of the circuit
3 SCL Serial Clock Line, used to provide clock pulse for I2C communication
4 SDA Serial Data Address, used to transfer the data through I2C communication
5 WAK Wake (active low)
6 INT Interrupt (active low)
7 RST Reset (active low)
8 ADD Single address select bit to allow alternate address to be selected

To use the sensor:

  1. Connect Vcc and Ground
  2. For a ESP8266, connect SCL and SDA (I2C) to D1 and D2 respectively.
  3. Connect WAK to ground

Using I2C, the device is on address 0x57.

MQ135 Air Quality Sensor

This module will return a high signal when the air quality meets a certain criteria.

DHT 11, DHT22

The DHT11 is a digital temperature and humidity sensor. They are notable by their blue perforated plastic package. The DHT11 is created by Aosong Guangzhou Electronics Co. Ltd. Each unit costs around $1.5 USD.

The DHT22, also called AM2302, RHT03, is similar to the DHT11 but offers a slightly wider operating temperature range and higher temperature and humidity resolution. The DHT22 is slightly more expensive at around $3 USD per unit.

The difference between the two modules are outlined in the table below.

DHT11 DHT22
Relative Humidity Operating Range 20 ~ 90% 0 ~ 100%
Relative Humidity Accuracy ±5%RH ±2%RH (Max ±5%RH)
Humidity Resolution 1%RH 0.1%RH
Humidity Repeatability ±1%RH ±1%RH
Humidity Hysteresis ±1%RH ±0.3%RH
Long-term Stability ±1%RH/year ±0.5%RH/year
Temperature Operating Range 0 ~ 50°C -40 ~ 80°C
Temperature Accuracy ±2°C ±0.5°C
Temperature Resolution 1°C 0.1°C

BMP085, BMP180, BMP280

These BMPs are atmospheric pressure sensors. They use I2C or SPI. The BMP280 appears to have superseded and are readily available on Ebay for around $0.50 and $1 USD each.

MAX30102

The MAX30102 is a heart rate monitor and pulse oximeter biosensor. These modules cost about $2 USD on AliExpress.

Using I2C, this has address 0x5A.

HC-SR501 Infrared Motion Sensor

The SR501 is an infrared motion sensor. They cost around $1.5 USD each. It has 2 potentiometers that are used to adjust the detection sensitivity and duration of the signal. The middle output pin gives a 3.3V signal when motion is detected and resets back to ground after a period of time.