We supply some different temperature and humidity sensors for your environmental monitoring projects. We also supply some enclosures and housings for your sensors. Please check them out below.

AHT21 Sensor

This is a high-precision intergated temperature and humidity sensor module for use with your Arduino or micrcontroller project.

It has an I2C interface so is easy to communicate with & Arduino libraries are available. Note: There is only one I2C address so it's not a good option when you need multiple humidity sensors on one I2C bus.

It's great for your environemental monitoring projects, maybe measuring temperature and humidity in your greenhouse or for weather monitoring.

The specifications are:

• Voltage supply: 2.2 - 5.5V DC
• Temperature range: -40℃ to 120℃
• Temperature accuracy: ± 0.3 ℃
• Humidity range: 0-100%

• Communication: I2C
• Sensor IC: AHT21

You get a 4 way header pin which you may want to solder on to use jumper wires, or add four wires to connect to your project.

Sensor details from the manufacturer are here.

The datasheet can be downloaded here.

There is an Arduino library for communicating to these devices here. There are others! I needed to download that library. Then I opened up the folder and zipped up the "AHT-main" folder. This can then be added to your Arduino libraries by "Include Library" -> "add .ZIP library" and then select the zipped "AHT-main" folder.

Here is a brief sketch to get you up and running.

The connections are:

• Sensor: VIN to Arduino: +5V
• Sensor: GND to Arduino: GND
• Sensor: SCL to Arduino: A5 (I2C Clock)
• Sensor: SDA to Arduino: A4 (I2C Data)

Solar Radiation Shield for AHT21

Want to measure outdoor temperature and humidity?

If you set up your sensor without a suitable enclosure, then it may not read the correct temperature –direct sunlight or wind onto the sensor can cause in-correct readings.

A solar radiation shield like this one protects the sensor from direct sunlight and strong winds, while still allowing it to read the humidity and air temperature.

This is a laser-cut acrylic case for housing an AHT21 sensor outside. It allows the air to pass over the sensor, while protecting it from direct sunlight and wind which can affect the readings.

This unit is laser cut from acrylic. It is comprised of layers which build up to create the enclosure. Screws at the top and bottom hold it all together.

Full design details and files (including instructions) are available in the github repository here:

https://github.com/curiouselectric/Sensor_Solar_Shield

This kit contains all the parts you need, apart from a 4 core cable to go from your logging unit/microcontroller to the sensor.

This kit INCLUDES the AHT21 sensor, so the cost is for the enclosure and the sensor!