Shinyei PPD42NS particle sensor

[RobTuDelft]

Anyone tried to attach the Shinyei PPD42NS sensor to a Pycom device?
It would be interesting to compare the results of this sensor with say a PMS5003 particle sensor on a Pycom device.

It is a very cheap sensor that can be used to measure air quality in a crude way.

More info here and here.

[PiAir]

Arrived in time for the hackaton this Saturday. :)

[Shaun]

@RobTuDelft Hi Rob, if you want the added info of particle size, you really do need to monitor both PWM outputs, but if you only plan on monitoring a single pin, then monitor the small particles pin.

I do take the duration of low pulse width on each pin into account too, at a resolution of 1ms.
The Amphenol sensor that I am using, I have noticed does not produce pulses narrower than 1ms

[RobTuDelft]

@Shaun The pulse width is also an indicator for particle size. So you could add counters based on the pulse length even with just one PWM output. Something I will test later.

[Shaun]

I have been running a unit for a couple of weeks now.
I hacked it onto an existing application PCB I developed around a WiPy.

The unit I use has 2x PWM outputs, one for larger particles and one for smaller particles

I am displaying real time readings, an exponential running average and a resettable peak hold.

[PiAir]

@RobTuDelft not just different nane, but also different price. I ordered 2 for €8,88 incl. shipping via AliExpress.
The grove connector is nice for the Marvin though.

[RobTuDelft]

Fyi, I'm using a LD1117A voltage regulator on the digital PWM input signal. It drops it from 4.5V to about 2.5V, which is enough for it to be a high signal on the Lopy.

My readings are around 400 pcs/0.01cf in the office.

I have resolved a few bugs in the code, so be sure to use the latest version from my Github.

@PiAir did you know you can also order them in the Netherlands under a different name?

[RobTuDelft]

@PiAir Sure, will bring it :)

[PiAir]

Cool, nice to collect other data than just temperature and humidity. I ordered one (two) from AliExpress, probably won't be here in time for Eindhoven, but maybe you can bring your setup and demonstrate it then? :)

[RobTuDelft]

I have created a library for this particulate matter sensor based on the Arduino code if anyone is interested.
You can find the code here.

Sensor needs to be connected to 4.75 - 5.25 V and you need to drop the voltage for the input port.

If you have any comments or questions let me know.