mirror of
https://github.com/RobTillaart/Arduino.git
synced 2024-10-03 18:09:02 -04:00
111 lines
3.4 KiB
Markdown
111 lines
3.4 KiB
Markdown
|
|
[](https://github.com/marketplace/actions/arduino_ci)
|
|
[](https://github.com/RobTillaart/MHZCO2/actions/workflows/arduino-lint.yml)
|
|
[](https://github.com/RobTillaart/MHZCO2/actions/workflows/jsoncheck.yml)
|
|
[](https://github.com/RobTillaart/MHZCO2/blob/master/LICENSE)
|
|
[](https://github.com/RobTillaart/MHZCO2/releases)
|
|
|
|
|
|
# MHZCO2
|
|
|
|
Arduino Library for MHZ series CO2 sensors.
|
|
|
|
|
|
## Description
|
|
|
|
The MHZCO2 is an experimental library for the MHZ19B CO2 sensor with a Serial (RS232-TTL) interface and compatibles.
|
|
|
|
The library offers a base class and derived classes to prepare for specific functionality.
|
|
The base class is based upon the MHZ19B specification. This might change in the future as compatibles might differ on detail.
|
|
|
|
Reference: user manual MHZ129B 2019-04-25 version 1.4
|
|
|
|
|
|
#### Compatibles
|
|
|
|
This list is not verified although these devices should be compatible based upon datasheet.
|
|
|
|
| type | precision | notes |
|
|
|:-----------|:----------:|:--------|
|
|
| MHZ1311A | 50ppm + 5% | energy saving version
|
|
| MHZ19 | 50ppm + 5% |
|
|
| MHZ19B | 50ppm + 3% | test device
|
|
| MHZ19C | 50ppm + 5% |
|
|
| MHZ19D | 50ppm + 5% |
|
|
| MHZ19E | 50ppm + 5% |
|
|
| MTP40F | |
|
|
|
|
Note: The calibration of the MHZ1311A is different than MHZ19x series
|
|
|
|
If there are compatible devices missing in this list, please let me know.
|
|
|
|
#### Links
|
|
|
|
- https://emariete.com/en/sensor-co2-mh-z19b/
|
|
- https://emariete.com/en/sensor-co2-low-consumption-mh-z1311a-winsen/
|
|
- https://revspace.nl/MHZ19
|
|
|
|
|
|
## Connection
|
|
|
|
- check datasheet of your sensor.
|
|
|
|
|
|
## Interface
|
|
|
|
#### Constructor
|
|
|
|
- **MHZCO2()** base class constructor.
|
|
- **MHZ19()** constructor. Also 19B,C,D,E
|
|
- **MTP40F()** constructor.
|
|
- **void begin(Stream \* str)** set the Serial port to use, e.g Serial1.
|
|
- **uint32_t uptime()** returns milliseconds since 'instantiation'.
|
|
|
|
|
|
#### Range
|
|
|
|
- **void setPPM(uint16_t PPM)** PPM = 2000, 5000, 10000
|
|
- **uint16_t getPPM()** returns (cached) PPM value
|
|
|
|
|
|
#### Measure
|
|
|
|
- **int measure()** workhorse, send command to read the sensor.
|
|
- **uint32_t lastMeasurement()** timestamp in millis of last measurement
|
|
- **int getCO2()** returns CO2 PPM last measurement.
|
|
- **int getTemperature()** returns temperature last measurement.
|
|
- **int getAccuracy()** returns accuracy last measurement.
|
|
- **int getMinCO2()** returns minCO2 last measurement.
|
|
|
|
The latter two might not be supported by all MH sensors.
|
|
|
|
#### Calibration
|
|
|
|
**WARNING:** use with care, read the datasheet as these commands may disrupt your sensor.
|
|
|
|
- **void calibrateZero()** Only use when sensor is at least 30 minutes in **400** PPM environment.
|
|
- **void calibrateSpan(uint16_t span)** Only use when sensor is at least 30 minutes in **2000** PPM environment.
|
|
- **void calibrateAuto(bool mode = true)**
|
|
|
|
|
|
## Future
|
|
|
|
#### Must
|
|
- improve documentation
|
|
- buy hardware MHZ19B / MHZ19C
|
|
- test with hardware
|
|
- verify checksum
|
|
- verify timeout
|
|
|
|
#### Should
|
|
- plotter example
|
|
- check 3000 PPM
|
|
|
|
#### Could
|
|
- extend unit tests
|
|
- add type info for derived classes?
|
|
- save RAM? possible?
|
|
|
|
#### Won't
|
|
|