Pi Zero Portable Air Quality Sensor — Construction in 10 “simple” steps.

Instructions on how to wire the RPi Sensor. This process takes ~2h for a first attempt. These are generic instructions related to the Born In Bradford project on measuring the air quality …

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1. Gather all the components and tools

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The component layout of the sensor

Component list:

Additional Equipment:


Pi Zero GPIO-pin Schematic

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RPI pin layout — NOTE: this is the other way round if you are looking at the pi upside down or backwards…

2. Prepare the equipment


3. Setting up the power switch for GPS and the OPC

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2N2222 Transistor

Transistor Schematics

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Resistance & some basic mathematics

( 3.3V (GPIO Pin) - 1.6V (Base) ) / 0.05 = 34 Ω
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It is always worth prototyping with a breadboard before soldering anything on.

Putting it all together


4. Adding the GPS unit

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Testing the unit

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A quick test using the 3.3v output on the PI

5. Connecting the OPC

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Flat taping the wires helps to preserve order

Alphasense OPC-R1

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https://py-opc.readthedocs.io/en/latest/

6. Connect the transistor to a driving pin

GPIO pin numbers: 4 7 8 9 10 11 14 15 17 18 22 23 24 25 27 30 31

7. Temperature & RH module

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8. Flash the Micro SD card


9. (Optional) Boot the device and check all is working with the Bluetooth app


10. Enjoy, Plot and Visualise!