A carbon monoxide detector or CO detector is a device that detects the presence of the carbon monoxide (CO) gas to prevent carbon monoxide poisoning. CO detectors are designed to measure CO levels over time and sound an alarm before dangerous levels of CO accumulate in an environment, giving people adequate warning to safely ventilate the area or evacuate.
An overview of the ME2-CO sensor
ME2-CO is an electrochemical sensor detect gas concentration by measuring current based on the electrochemical principle, which utilizes the electrochemical oxidation process of target gas on the working electrode inside the electrolytic cell, the current produced in the electrochemical reaction of the target gas is in direct proportion with its concentration while following Faraday law. The concentration of the gas could be obtained by measuring the current value.
Specification
Application
- Output Type: Analog-Voltage/Digital-Logic
- Detection Range: 0 to 1000 ppm
- Resolution Ratio: 0.5 ppm
For more specifications, please refer to datasheet
Widely used in commercial especially residential occasions to detect CO gas concentration.
ME2-CO module Key Features
- User-selectable module power supply voltage between 3V3 and 5V
- On Board, ON/OFF LED indicator
- On Board LED indicator for Digital Comparator Output
- 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 ME2-CO module
GebraBit ME2-CO is an Electrochemical Carbon Monoxide measurement module which can operate with “3V3” or “5V” supply Voltages by Considered bottom selector jumper. GebraBit ME2-CO module amplifies ME2-CO sensor output by an integrated op-amp circuit for better analysis and interpretation and provides it on the module “AO” pin. For reading CO data, just connect the analog “AO” pin to MCU ADC and go on. The Gas intensity threshold is adjustable by an embedded potentiometer on the GebraBit ME2-CO module.
Users need a starter circuit and driver for hardware development and of course software development of the ME2-CO sensor. GebraBit has done this by implementing the ME2-CO sensor circuit and provided access to its output for users.
It is enough to put the GebraBit ME2-CO module in the BreadBoard, then by applying the proper voltage set up the GebraBit ME2-CO 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 receive the data.
The reason for our recommendation when setting up the GebraBit ME2-CO module with GebraBit microcontroller development modules (such as GebraBit STM32F303 or GebraBit ATMEGA32), is the presence of the 3V3 regulator and the compatibility of the pin order of all GebraBit modules together (GEBRABUS standard), it’s enough to Put the ME2-CO 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
ME2-CO sensor
The ME2-CO sensor is the main IC of this module, which is responsible for measuring carbon monoxide gas and is placed on top of the module and its circuit is designed.
Supply voltage selector jumper
According to the state of 0R resistance of this jumper, the sensor supply voltage is selected between 5V and 3V3.
Amplifire
An integrated op-amp circuit is used on the GebraBit ME2-CO module to amplify the output of the ME2-CO sensor for better data analysis.
Sensitivity potentiometer
In designing the ME2-CO sensor circuit, a potentiometer is used to determine the module sensitivity.
Comparator
In the ME2-CO sensor circuit design, a comparator is used to compare the sensor output with the set threshold.
Dout LED
When the Gas intensity goes above, or below the threshold, the “Dout” LED status will be changed.
Power LED
According to the status of the module power selector jumper and by applying voltage to the module through the corresponding pin, the LED of the module turns on.
GebraBit ME2-CO Module pins
Supply pins
- 3V3 and 5V: These pins can supply the power supply of the sensor circuit according to the state of the power voltage selector jumper.
- GND: This is the ground pin for powering the sensor.
Output pins
- AO: This pin is used to receive the analog output of the module. To read the sensor output data, it is enough to connect this pin to the ADC of the microcontroller.
- DO: This pin is used to receive the digital output of the module and when the gas intensity is higher or lower than the set threshold, the logic output (0 and 1) also changes.
Connect to the processor
Connection with GebraBit STM32F303
Due to the compatibility of the pin order of GebraBit modules with each other (GEBRABUS standard), to start the GebraBit ME2-CO module with GebraBit STM32F303 microcontroller module, it is enough to easily place the GebraBit ME2-CO module as pin to pin on the GebraBit STM32F303 module and start the module by applying voltage. Here, for better understanding, the separate connection of these two modules is shown:
Connection with GebraBit ATMEGA32A
Due to the compatibility of the pin order of GebraBit modules with each other (GEBRABUS standard), to start the GebraBit ME2-CO module with the GebraBit ATMEGA32A microcontroller module, it is enough to easily place the GebraBit ME2-CO module as pin to pin on the GebraBit ATMEGA32A module and start the module by applying voltage. Here, for better understanding, the separate connection of these two modules is shown:
Note: If you use GebraBit microcontroller modules, make sure that the GebraBit ME2-CO module power selector jumper is set to “3V3” so that you can easily get the “3V3” voltage from the microcontroller module.
Connection with ARDUINO UNO
Follow the steps below to connect the GebraBit ME2-CO module to ARDUINO UNO:
- Connect the “5V” pin of the ME2-CO module to the “5V” pin of the ARDUINO UNO board output (red wire).
- Connect the “GND” pin of the ME2-CO module to the “GND” pin of the ARDUINO UNO board. (Black wire)
- Connect the “DO” pin of the ME2-CO module to one of the ARDUINO UNO board digital pins (blue wire).
- Connect the “AO” pin of the ME2-CO module to one of the ARDUINO UNO board analog pins (orange wire).
How to connect the above mentioned steps can be seen in this picture: