Air quality sensors are devices used to detect particles, pollutants, and harmful gases in the air that may be harmful to human health. They are used in air quality monitoring, gas detection in industry, combustion controllers, oxygen generators in plane, etc…
Volatile organic compounds or VOCs are created when harmful chemicals evaporate at ambient temperature. Large manufacturing factories that use toxic solvents or chemicals during production can release dangerous levels of VOCs into the air. These gases create photochemical smog, which can cause severe problems for human health and harm the environment.
VOC sensors are made to detect any changes in certain gases and send the data to a central monitoring system. The factory personnel use these sensors to prevent any unexpected increase in the emission of these types of gases. Depending on the type of sensor used, technicians can calibrate each device to detect a specific VOC or a group of them.
An overview of the SGP41-D-R4 sensor
The SGP41 is a digital gas sensor designed for easy integration into air purifiers or demand-controlled ventilation systems. This sensor features a digital I2C interface and temperature- controlled micro hotplates, providing one VOC and one NOx based indoor air quality signal.
Specification
Application
- Output Type: Digital-I2C
- Detection Range: 0 to 1000000ppb (Ethanol in clean air), 0 to 10000 ppb (NO2 in clean air)
For more specifications, please refer to datasheet
In limited spaces applications and high-volume applications
SGP41-D-R4 module Key Features
- User-selectable module power supply voltage between 3V3 and 5V
- On Board, ON/OFF LED indicator
- GebraBit Pin Compatible with GEBRABUS
- It can be used as a daughter board of GebraBit MCU Modules
- Featuring Castellated pad (Assembled as SMD Part)
- Separatable screw parts to reduce the size of the board
- Package: GebraBit small (36.29mm x 32.72mm)
GebraBit SGP41-D-R4 module
GebraBit SGP41-D-R4 Air Quality module for VOC and NOx Measurements. GebraBit SGP41-D-R4 operates with 1V8 and 3V3 Supply Voltages that users can easily select with jumper selector of the module. User can interface with GebraBit SGP41-D-R4 by I2C protocol with the module.
Due to the sensor DFN package and since it’s difficult to access to sensor pins, user needs a starter circuit and driver for the hardware development and of course the software development of the SGP41-D-R4 sensor. For the convenience of users, this work has been done by implementing the SGP41-D-R4 sensor circuit and providing access to the sensor important pins.
It is enough to put the GebraBit SGP41-D-R4 module in the BreadBoard, then by applying the proper voltage set up the GebraBit SGP41-D-R4 module with any of Arduino, Raspberry Pi, Discovery board, and especially we recommend using GebraBit microcontroller development modules (GebraBit STM32F303 or GebraBit ATMEGA32 module) then receiving the data.
The reason for our recommendation when setting up the GebraBit SGP41-D-R4 module with GebraBit microcontroller development modules (such as GebraBit STM32F303 or GebraBit ATMEGA32), is the presence of an internal 3V3 regulator on these modules and the compatibility of the pin order of all GebraBit modules together (GEBRABUS standard), it’s enough to Put the SGP41-D-R4 in the corresponding socket as shown in the above picture and develop the desired sensor module without the need for wiring.
Introduction of module sections
SGP41-D-R4 sensor
SGP41-D-R4 is the main IC of this module, which is responsible for air quality control, VOC and NOx measurement, and it is placed on top of the module and its circuit is designed.
VDD SEL jumper
According to the state of 0R resistance of this jumper, the main voltage of sensor power supply is selected between 1V8 and 3V3.
Power LED
According to the state of the VDD SEL jumper and applying voltage to the module by the corresponding pin, the LED of the module will be lit.
GebraBit SGP41-D-R4 Module pins
Supply pins
- 3V3 and 1V8: These pins can supply the sensor main power supply and the logic level of the sensor digital connection (I2C) according to the state of the VDDSEL selector jumper.
- GND: This is the common ground pin for power and logic level of the sensor.
I2C pins
- SDA: This pin is the I2C communication data pin, which is connected to the corresponding data pin in the microcontroller (processor). According to the state of the VDD SEL jumper, you can use the logic level with a voltage of 1V8 or 3V3.This pin is pulled up with a resistor.
- SCL: This pin is the I2C communication clock pin, which is connected to the corresponding clock pin in the microcontroller (processor). Depending on the state of the VDD SEL jumper, you can use the logic level with a voltage of 1V8 or 3V3. This pin is pulled up with a resistor.
Connect to the processor
I2C connection with GebraBit STM32F303
For I2C connection of GebraBit SGP41-D-R4 and GebraBit STM32F303 microcontroller module, after defining SDA and SCL on pins PB9 and PB8 (for convenience in STMCUBEMX), follow the below steps:
- Connect the 3V3 pin of the SGP41-D-R4 module to the 3V3 output pin of the microcontroller module. (Red wire)
- Connect the GND pin of the SGP41-D-R4 module to the GND pin of the microcontroller module (Black wire).
- Connect the SCL pin of the SGP41-D-R4 module to the PB8 pin of the microcontroller (SCL) module (Blue wire).
- Connect the SDA pin of the SGP41-D-R4 module to the PB9 pin of the microcontroller (SDA) module. (Yellow wire)
You can see how to connect the above mentioned steps in this picture:
Note: Considering that the PA14 pin of the GebraBit STM32F303 microcontroller module is used to program the microcontroller, I2C setting on the PA14 and PA15 pins is impossible in this version, so in this version for I2C connection with the GebraBit STM32F303 microcontroller module, GebraBit SGP41-D-R4 module cannot be placed on it as Pin to Pin. To make a more convenient connection between the two modules, you can select the SPI protocol by using the on-board jumpers and then place the GebraBit SGP41-D-R4 module as Pin to Pin on the GebraBit STM32F303 module.
I2C connection with GebraBit ATMEGA32A
Considering that the I2C pins of the ATMEGA32A microcontroller are based on the GEBRABUS standard and correspond to the I2C pins of other GEBRABIT modules, the GebraBit SGP41-D-R4 module can be placed pin to pin on the GebraBit ATMEGA32A module and communicate with the GebraBit SGP41-D-R4 module via I2C. Here, for better understanding, the separate connection of these two modules is shown:
Note: If you are using GebraBit microcontroller modules, note that the jumper selectors of the GebraBit SGP41-D-R4 are set to 3V3 so that you can easily power-on the GebraBit SGP41-D-R4 module by getting the 3V3 voltage from the microcontroller module.
I2C Connection with ARDUINO UNO
Follow the below steps to connect the GebraBit SGP41-D-R4 module to the ARDUINO UNO via I2C:
- Connect the 3V3 pin of the SGP41-D-R4 module to the 3V3 output pin of the ARDUINO UNO board. (Red wire)
- Connect the GND pin of the SGP41-D-R4 module to the GND pin of the ARDUINO UNO board (Black wire).
- Connect the SCL pin of the SGP41-D-R4 module to the A5 pin of the ARDUINO UNO board (SCL). (Blue wire)
- Connect the SDA pin of the SGP41-D-R4 module to the A4 pin of the ARDUINO UNO board (SDA). (Orange wire)
You can see how to connect the above mentioned steps in this picture: