How do I use the Metriful MS430 sensor board?
The MS430 is controlled with a host system, which supplies power and reads the measured data.
There are thousands of embedded computers, microcontrollers and development boards that you can use as a host, including Raspberry Pi and Arduino. As Metriful is self-managing, the host is free to do other tasks while the environment is being monitored.
Does it work with Raspberry Pi?
Yes! Get a Metriful sensor board with soldered header and connect to Raspberry Pi using connecting "jumper" wires, no soldering needed. Optional separate PPD42 and SDS011 particle sensors can also be connected this way.
Our Python code examples run on Raspberry Pi, helping you get started immediately.
What are the minimum requirements for the host system?
The host must have an I2C-compatible port, run at either 3.3 V or 5 V, and have at least one digital input (three digital inputs for full functionality).
Raspberry Pi, Arduinos, and many other embedded computers, microcontrollers and development boards meet these requirements.
What are the code examples?
The host system must run software code that:
1. Gets data from the MS430, then:
2. Does something with the data.
Data could be displayed on a screen, sent to the IoT cloud, saved to a file, or used to control a home appliance. You can use one of our code examples (hosted on Github), modify it, or write your own.
Note: wired or wireless internet connection is required for some code examples. Examples are currently available for Raspberry Pi, Arduino Uno, Arduino Nano 33 IoT, Arduino MKR WiFi 1010, Arduino Nano, NodeMCU. Many other host systems can be used but require adaptation of the examples.
What does it measure?
The MS430 measures eighteen variables describing the indoor environment, including:
Air quality, temperature, humidity, pressure, illuminance, white light level, sound noise, sound frequency bands, sound peak amplitude, air particle concentration*.
A full list and further details are given in the User Guide, available on our Github page.
*Using an external particle sensor (purchased separately)
What is a jumper wire?
Sometimes called "Dupont" wires, these let you electrically connect circuit boards and/or breadboards with an easy push-fit. The wire ends have pins/sockets allowing connection to sockets/pins. To be compatible, circuit boards must first be fitted with header pins/sockets (attached by soldering).
Some systems (Raspberry Pi and Arduino Uno) can use jumper wires without any breadboard. Other systems (e.g. Arduino Nano 33 IoT) need a breadboard as well as jumper wires.
What is a soldered header?
Headers are a strip of metal pins that allow a circuit board to be connected to jumper wires or breadboards with an easy push-fit. They are present on Raspberry Pi and most Arduinos.
Headers must be soldered to the circuit board before use. We supply sensor boards with unsoldered or (for a small extra charge) soldered headers.
There are two styles to choose from: straight pins (best for breadboards) or right angle pins (best for jumper wires).
If you choose a board with soldered headers, you can use jumper wires to connect to Raspberry Pi, or other systems, without doing any soldering.
How do I use it in the Internet of Things (IoT)?
Data measured by the MS430 can be sent to other devices over the internet. You can use this to store data, review and assess your environment, or even respond automatically (home automation).
Our Github page contains code examples and instructions for setting up IoT data logging and visualization with Arduino and Raspberry Pi. This automatically stores data in an IoT cloud and lets you visualize it online, live, anywhere in the world.
How frequently are measurements made?
In the standard mode, you can choose automatic measurements every 3 seconds, 100 seconds, or 5 minutes.
Alternatively, measurements (excluding air quality) can be made on-demand at any rate up to 4 Hz.
What does the air quality measurement mean?
The MS430 has a highly responsive metal-oxide sensor for volatile organic compounds (VOCs), a class of potentially harmful air impurities. Measurements from this sensor, together with humidity and temperature data, are input to an intelligent monitoring algorithm. This calculates an Air Quality Index value to describe the condition of the surrounding air. The value ranges from 0 to 500; lower values indicate better air quality.
How are air particulate measurements made?
The MS430 has an input connection and internal algorithms for analyzing the signal from a particulate matter sensor. This sensor is optional and must be purchased separately. There is a choice of two sensors: the Nova SDS011 and the Shinyei PPD42; both are available from many suppliers worldwide. Further instructions are given in the User Guide, available on our Github page.
How do the sound and light interrupts work?
The sensor board has two digital output signals which are rapidly activated by changes in sound and light levels. The threshold level and behavior of these can be programmed by the host system. They can be used to trigger interrupts on the host, wake the host, or drive external circuits directly (e.g. LEDs).
Is the onboard microcontroller reprogrammable by the user?
The onboard Arm microcontroller is fully utilized for data processing, sensor management and communications. It is non-programmable to protect these functions.
How do I learn more?
Our Github page at https://github.com/metriful/sensor
contains detailed code examples, User Guide, Datasheet and setup guide.
Which sensor components are used?
Air quality, temperature, pressure, humidity: Bosch Sensortec BME680
Light: Vishay VEML6030
Sound: Knowles SPH0645LM4H-B
Particulate matter (optional separate purchase): Nova SDS011 or Shinyei PPD42 (NJ/NS)