Best air quality sensor to connect to TTN?

End Devices (Nodes) Hardware
1

Hi!

I’m a complete newbie and would like to know the best (affordable) types of air quality sensor to communicate with the Things Gateway?

Thanks

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2

It depends on what you want to measure, gasses, particulates, etc. There are different sensors for each, all with their own specification and use. You’d also need to consider the calibration and accuracy of the sensors and how you’d verify that the readings they produce are correct.

thanks

Andrew

3

Air quality is a complex matter. There are many sensors out on the market, but I have stumbled upon only two coming products specifically designed for LoRa. One is called LP8 from SenseAir in Sweden. The other one is from SensorsConnect, you can read about it in this blog post. And the previous blog post briefly covers air quality.

Volatile Organic Compounds are interesting especially regarding indoor air quality. For cheap sensors to make DIY modules you might want to take a look at what Seeed has to offer, and especially their list of how to choose a gas sensor.

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Thanks @thinginnovations . Let’s say I’d like to measure NO2 and CO2 concentrations. Any particular sensors you can suggest that are LoRaWAN compatible? I’m just looking for something fairly basic to get started on a very simple project - measuring air quality outside my home using the Things Gateway.

Also, could you elaborate on the issue of verifying accuracy of readings?

Thanks!

5

Thanks @flonnfor for the pointers. The initial two sensors you mentioned are not yet available though, are they?

6

Unrelated to LoRaWAN, for the Dutch, from the National Institute for Public Health and the Environment (Rijksinstituut voor Volksgezondheid en Milieu, RIVM):

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You are right, they can’t be purchased yet. Although SenseAirs product might be ready, maybe we should mail and ask :smile:

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Just my two cents.

A lot of those airquality sensors use a lot of power. Some of them need to be preheated for quite some time. One of the USPs for LoRa is it’s incredible small powerusage. So airquality and LoRa may not be the best combination, I would use some WiFi stuff, for example an ESP.

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Power usage is one USP. Range is another advantage. ESP modules need an access point nearby. 3G requires a SIM, so LoRa is an excellent fit for powered sensors requiring low bandwidth connectivity.

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10

Here is GasSensingSolutions’ product family of NDIR CO2 sensors. Some have a continuous power consumption of 3.5 mW, peak current 33 mA and average current < 1.5 mA, with two readings per second. Warm-up time < 10 seconds, time to first reading 1.2 seconds. If someone sees better specs, please share.

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I found this old thread about air quality sensors on TTN. Could @Wojtek tell us if something has happened since then ?

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I think Wojtek is the author of the blog post by iotman that you refered to in your earlier post.

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In that case I went full circle without knowing it. Thank you for noticing!

14

Hello
The hardware is still being tested While we still adding finał touches to the firmware. At this point we are still tweaking calibration mode and energy saving modes. Provisioning done over LoRaWAN, pretty cool actually.

Thanks
Wojtek

15

Thank you for giving a status report. Provisioning over LoRaWan sounds great! Are there any specs you can share with us already ? Primarily regarding the sensors. And what is your planned schedule for getting the product ready ?

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cheap diy dust sensor

some other links

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Because of the domain name, a little bit misleading URL, but interesting content about measuring pollution in different particle sizes. Though not calibrated, they seem to come very close to calibrated devices. Would certainly provide usefull indicative figures for citizens who suffer from traffic and wood stove pollution.

18

Hi,
We are measuring the following data:
CO
NO2
O3
PM2.5
Temperature
Humidity
GPS coordininates
Optionally, PM10 and SO2

Sensors, with exception of SO2 need to be calibrated and we provide such mechanism. It will require “clean room” or something close to it and can be invoked using our LoRaWan provisioning mechanism. Also, calibration values can be pushed to node over LoRaWan. In addition, we support number of different operating modes, especially for GPS, where you can do a lookup once or do it in a continuous mode or cold standby mode (shut down gps power between measurements). In addition, user can obviously specify time measurements. Each node uses Lithium Polymer battery which can be charged using a solar panel or just plain USB PS. We are extremely busy, but you should see more details on our web site soon. We haven’t decided yet if we will provide persistent data storage, but today we use InfluxDB and Grafana to visualize the results
Thanks
Wojtek

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Hi Wojtek are these LoRa devices available yet? I Am really interessed in some testing results

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We are just waiting for a final pre-production batch. We expect to have first units available in mid September. We end-up removing SO2 sensor and adding barometric pressure sensor due to requirements driven by our first volume customer.
We will also provide application server which will interpret the data and store it in InfluxDB for persistency. In addition, there is a RESTful API for provisioning (CLI and web based) parameters of the node. Nodes will operate on TTN and/or private network based on brocaar Lora Server. Stay tuned…
Wojtek