I backed at the custom shield level and my request was to have a Figaro TGS2602 hydrogen sulfide sensor on a custom shield. Figaro Sensor PDF There have been discussions with Spark about expanding the shield. Other possibilities discussed : Adding a combined Temperature and Humidity sensor Addi…

omg, that looks awesome! please keep us posted on your results!

Hi @zach and @mohit - these are my findings from working with the shield the last couple of months. Recommendations : Replace no longer available MICS-5525 (CO) with MICS-4514 (CO and NO2) Programmatic switching of power to heaters for all sensors. Maintain power to temperature/humidity sens…

@zach and @mohit - this is the progress I have made so far on the software for the shield : [image] Custom Shield - Indoor Air Quality Monitor (Open Source Software) I have been working on the software for the Indoor Air Quality Shield. This is the open source code for it : https://gi…

@Rockvole , just a note, @mtnscott has published an updated version of the non-blocking DHT library which seems much more stable, at least under “simple” test conditions. What I mean by simple is testing without any other libraries like the ones you are using. I have been running the code through 1…

I notice in your long-running test you dont use a pullup resistor. I think my shield has a pull-up resistor on the DHT22 - do you think that needs to be removed to make it more reliable ?

@rockvole , I recommend using a 1K pullup resistor on the data line for the DHT22. [image] [Submission] Updated Non-blocking Interrupt Driven DHT Sensor Library I have published an updated version of the DHT interrupt driven sensor library. It now supports DHT22 and DHT11 sensors. It h…

@Rockvole , I agree with @mtnscott that a pull-up is needed. I just wanted to point out the fact that I was running without one to qualify all test conditions. :smile:

Thanks @peekay123 and @mtnscott , If you guys think it is reliable now then I’m happy to stick with the DHT22. Its cheap so it will help keep costs down.

It looks like there is another dust sensor coming soon. Specifically for PM2.5 - which is the standard used by governments. It makes the grove dust sensor look compact : http://www.dfrobot.com/community/new-air-quality-monitor-is-on-the-way.html

It looks like the new DHT library is reliable so I dont believe upgrading to the SHT15 will be needed.

Custom Shield - Indoor Air Quality Monitor

Hardware

mtnscott October 17, 2014, 11:43pm 113

@rockvole, I recommend using a 1K pullup resistor on the data line for the DHT22.

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Custom Shield - Indoor Air Quality Monitor

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