Environmental monitor

This is a small curcuit board with a range of environmental sensors and very flexible installation options.

• True CO₂
• Humidity
• Temperature (see below, including WAGO for DS18B20, and BLE)
• Atmospheric pressure
• Noise
• Light (including colour)

It can be powered from USB-C, a DC supply (5V-28V), or PoE (with Ag9912-LP fitted). It can communicated over Ethernet or 2.4GHz WiFi. This makes it ideally suited for many applications.

• Home use would typically be USB-C and WiFi
• Office use (and well set up home) would typically be PoE / Ethernet
• Data centre use would typically be USB-C and Ethernet, as data centres rarely have WiFI or PoE
• It can also have a Waveshare 2" colour LC Display - either directly on the board, or using cable.

This can be loaded with various software like ESPHome. The provided software works with Home assistant.

Includes

• ESP32-S3-MINI-1-N4-R2, Dual CPU, 4M flash, 2M SPI RAM, WiFi
• USB-C for power and programming
• 10/100 Ethernet
• SCD41 for CO₂
• SHT40 temp/humidity
• GZP6816D for pressure
• VEML040 for light
• T3902 for sound
• DC power (WAGO) up to 28V
• DS18B20 connection (WAGO)
• 4 WS2812 style LEDs
• Header for board mounted Waveshare 2" colour LC Display
• Alternate header for leaded connection to Waveshare 2" colour LC Display
• Pads for additional I2C devices

Temperature

Temperature sensors are a lot more complicated than they may seem - this is partly because temperature can vary in short distances in a room, but also because a sensor can be thermally coupled to devices generating heat on the same PCB or in the same case. Whilst some types of sensor need no calibration, it is sensible to consider calibration for on-board sensors. Do this by running the device for some minutes in the installed location, with any case to allow temperature to stabalise, and then use a calibrated temperature probe to establish a temperature offset to apply.

The range of temperature sensors includes :-

• SHT40 on board sensor. This is very accurate, and has been placed at the edge of the board on a long thin strip of PCB with no ground plane so as to minimise thermal coupling. The 3D case design also has an opening for the sensor to minimise thermal coupling via air in the case. This is ideal for simple ambient temperature.
• SCD41 CO₂ sensor has temperature, but this is not thermally isolated, so calibration is recommended.
• GZP6816D pressure sensor has temperature, but this seems less reliable and not recommended.
• DS18B20 via a WAGO on board. This does not need calibration as is very accurate. One or more leaded probes can be connected (some practical limit on how many wires can be twisted together in to a WAGO) - this allows temperature sensing in specific location, e.g. at home it could be inside and outside, and in a data centre front and back of rack, etc.
• BLE battery sensors can be used as well - these also allow temperature at specific locations in a room, and do not need calibration or adjustment.

Options

• PoE module (needs soldering to board)
• Waveshare 2" colour LC Display (needs 8 pin header soldering on, unless using supplied cable)
• Resin 3D printed case
• Soldering option - I'll solder display connector and PoE for you

All parcels shipped with tracked shipping, usually shipped within one working day.