ESP32 Temperature and (optional) mmWave Radar presence sensor case

Introduction:

This is an ESP32 D1 mini case for temperature and an optional mmWave Radar presence sensor. Optimised for space efficiency and the placement of the temperature sensor has been optimised to minimise self heating from the ESP32.

I've used this case to house my D1 Mini ESP32 together with the DF Robot mmWave radar presence sensor and a BME680 temperature, humidity and air quality sensor. This makes it a very powerful all-in-one sensor for your living and sleeping areas.

I've also used this case to house a temperature only sensor using a D1 Mini ESP32 and an Fermion SHT35 sensor from PiHut for areas where presence detection is not required.

Both projects run ESPHome and send data over to your HomeAssistant instance but similar outcomes can be achieved using Arduino.

To Print:

1. Select the appropriate lid: if you are using an mmWave radar use the one with the two icons (motion and temperature). If not, use the one with the temperature icon only 
2. Multi-colour: If printing the lids in multicolour, select the lid and the corresponding icons and import them in the slicer as one part. Then use the slicer to paint the icons to the desired colour.
3. Orientation: The divider and lid need to be printed face down. Click “auto orient” in the slicer to set them to the print orientation.
4. Layer height: I recommend a fine layer height - 0.12 or 0.16 due to the fine details on the inside of the case. 
5. Sensor placement: There are two positions available to install the temperature sensor PCB - on the left side facing to the outside of the case and on the bottom side facing down. I recommend the BME680 sensor is placed on the slot facing to the left of the case and the SHT sensor to the one facing down to minimise the effect of self heating on the sensor. If using a mmWave radar, the ESP32 needs to be on continuously, therefore the case will heat up more so the sensor needs to be as far away as possible from the ESP32 and as close as possible to the bottom vent holes.
6. Securing the ESP32: Use some double sided tape to secure the ESP32 in the case. Place the double sided tape on the cut out region in the shape of the ESP32 chip on the right hand side of the case.
7. I have included two versions of the bottom case. One has the vertical temperature sensor mount positioned a bit closer to the centre of the area and one on the left hand side of the sensor housing. I have found that the second version offers slightly better reduction in heat transmission from the ESP32 to the sensor, hence slightly more accurate temperature readings. However it may not work for you, hence including both versions.

Bill of Materials:

For this project you'll need:

1. D1 Mini NodeMCU ESP32 (for example this: https://www.amazon.co.uk/AZDelivery-ESP-WROOM-32-Bluetooth-Development-Compatible/dp/B08BTLYSTM/)
2. SHT35 sensor (temperature and humidity) or BME680 sensor (temperature, humidity, air pressure and air quality). For example: https://www.amazon.co.uk/CJMCU-680-Temperature-Humidity-Ultra-small-Development/dp/B07K1CGQTJ/ and https://thepihut.com/products/fermion-sht35-digital-temperature-humidity-sensor
3. Optionally a DFRobot mmWave radar to detect presense: https://www.dfrobot.com/product-2282.html 
4. Cables: https://www.amazon.co.uk/Elegoo-120pcs-Multicolored-Breadboard-arduino-colorful/dp/B01EV70C78/
5. micro USB cable and a USB phone charger

ESPHome Code:

Visit the below github page for sample code for this project: https://github.com/igiannakas/Presense-Temperature-Humidity-Air-Quality-multi-sensor-DFRobot-SHT35-or-BME680-