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We have open source, open hardware build instructions for a very reliable Air quality sensor that can be used to measure PM2.5 and also CO2. https://www.airgra

We have open source, open hardware build instructions for a very reliable Air quality sensor that can be used to measure PM2.5 and also CO2. https://www.airgradient.com/diy/ https://www.airgradient.com/diy/ We have tested it extensively and it is very accurate for the fraction of the costs of commercial sensors. You can build it for less than USD 20 and send the data to our cloud server or any other backend. We also measure CO2 because if you have purifiers running you often do not have enough fresh air ventilation and your CO2 often gets very high (often >1500ppm) causing headaches and reduce cognitive performance. We measured this in classrooms some time ago and the results were not very good. Details. https://www.airgradient.com/blog/2020/02/07/we-measured-the-co2-level-in-a-classrooms-this-is-what-we-found-out/ https://www.airgradient.com/blog/2020/02/07/we-measured-the-...

azmodeus 6y ago
It would be nice if preassembled kits could be purchased from you. I would be happy to pay USD 40 for a good preassembled kit.
- headmelted 6y ago
  This. I no longer have access to a soldering iron and want a bunch of these, not enough that it's worth the cost of buying equipment and the time spent making them. Help us give you money! :-)
  - joshmlewis 6y ago
    You can get good soldering irons for less than $100.
    - headmelted 6y ago
      Yeah but I have to buy the soldering iron then spend my time figuring the kit out and doing the job. I’d be happy to pay OP for their work and everyone wins.
- cinntaile 6y ago
  The BOM already costs more than USD 40 so USD 80 is probably a more realistic number for a preassembled kit.
  - azmodeus 6y ago
    Would be happy to pay USD 80 for it as well
- dmitriid 6y ago
  Once you start assembling and selling these, you'll quickly realise why many things are priced the way they are. Especially low-volume tings like "pre-assembled DIY kits"
- EricE 6y ago
  Way too low for that - good rule of thumb is 1.5x to 2.5x the cost of materials for labor if someone else is going to do it for you.
shared_frog 6y ago
I appreciate your DIY instructions, but I really dislike how your website goes through the effort of hiding what you actually sell and also how much it costs. I don't want to "contact you" to get that information. We've been long enough in the 21st century that it has become an adult, and still I keep running into this archaic nonsense. For example, you mention your "sensor package" in the FAQ and that's it. Your DIY instructions mention the "AirGradient PCB", _but there is no place where I can buy it_. For the love of god, put a 'buy' button on your website.
- Semaphor 6y ago
  The PCB is not sold by them, they have the Gerber files for download, and you can upload them here [0] to have it made and shipped to you. It seems what they are selling are consulting services with possible parts depending on the results, if you don’t want to do everything yourself. [0]: https://jlcpcb.com https://jlcpcb.com
- xwdv 6y ago
  They want to change what they charge from time to time so putting a price up front will force them to leave money on the table. Not gonna happen. Contact them instead.
  - bigiain 6y ago
    Instead of contacting them, I will spend a little time investigating whether there's someone else I can buy from, who doesn't consider being "forced to leave money on the table" makes this a reasonable way t treat potential customers, and will choose to spend money at a less customer hostile business - or possibly do without the product. Contacting some random "enterprise sales" team? Not gonna happen.
    - xwdv 6y ago
      What if they put an upfront price of $100 dollars but cheaper prices available if you contact them?
jsingleton 6y ago
It looks like you're using a Plantower PMS5003. I have one of those hooked up to a Raspberry Pi and it works well but I also built a few of these with ESPs: https://sensor.community/en/sensors/airrohr/ https://sensor.community/en/sensors/airrohr/ They support the PMS but I used the default SDS011. They both seem reasonable for relative values but I'm not sure about the accuracy without proper calibration. They don't appear to give similar readings to my Plume Flow 2: https://plumelabs.com/en/flow/ https://plumelabs.com/en/flow/
throwaway9d0291 6y ago
I've seen references to this sensor before and find it a bit concerning that there's no information about how to properly use the CO2 sensor. This sensor uses a SenseAir S8, which like most CO2 sensors, has an automatic baseline calibration algorithm enabled [0], which expects to see pure, undiluted fresh air at least once every 8 days. The only way to disable it is explicitly, through the MODBUS interface [1]. Leaving it enabled makes perfect sense in a business or businesslike environment because these environments will be completely unoccupied overnight and have air conditioning, which usually does a daily fresh-air purge, ensuring that the sensor will have regular exposure to fresh air. However in a residential environment, the auto baseline calibration often doesn't make sense, especially in winter. When the windows are closed and/or people or pets are around, it's very rare for the sensor to see uncontaminated fresh air, so it will see say 500ppm of CO2 and assume it's fresh air when it really isn't. I have measured this and it's a real problem. In a residential environment, unless you're sure you have good, frequent exposure to pure fresh air, you're better off doing a fixed calibration once a year or so. AirGradient also seems to be a hardware-only design. The ESPHome project [2] has great software support for a variety of sensors (including the SenseAir S8, so it should be compatible with the AirGradient hardware) as well as a very well-documented hardware project [3]. After trying my own Arduino-based software and then ESP-IDF, I find esphome much more pleasant to work with. [0]: https://rmtplusstoragesenseair.blob.core.windows.net/docs/publicerat/PSP107.pdf https://rmtplusstoragesenseair.blob.core.windows.net/docs/pu... [1]: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE2067.pdf https://rmtplusstoragesenseair.blob.core.windows.net/docs/De... [2]: https://esphome.io/ https://esphome.io/ [3]: https://github.com/nkitanov/iaq_board https://github.com/nkitanov/iaq_board
- cleorama 6y ago
  Is there a CO2 sensor (part) and/or a CO2 monitor (device) one can buy that is well-suited for residential spaces?
  - throwaway9d0291 6y ago
    Any CO2 sensor (part) that gives you the ability to turn off ASC should work just fine and most of them do, you just need to trigger it. Personally, after trying out a bunch of sensors, I use the Sensirion SCD30. As for devices, I'm not aware of a consumer device that I'd recommend. If you're willing to do at least a little bit of DIY, Watterott [0] sells an SCD30 hooked up to an Arduino-compatible MCU with WiFi, a red/green/blue indication of CO2 levels and ASC disabled by default [1]. It's an open-source hardware design and software [2] and has a few reference firmwares [3], including one [4] for MQTT. If you want to go a little bit further, I'd recommend an ESP32 with an SCD30 and ESPHome [5]. That's what I use myself, mostly because I already had the sensors prior to Watterott's product existing. [0]: https://shop.watterott.com/ https://shop.watterott.com/ [1]: https://shop.watterott.com/CO2-traffic-light-Plus-version-Wifi https://shop.watterott.com/CO2-traffic-light-Plus-version-Wi... [2]: https://github.com/watterott/CO2-Ampel https://github.com/watterott/CO2-Ampel [3]: https://learn.watterott.com/breakouts/co2-ampel/ https://learn.watterott.com/breakouts/co2-ampel/ [4]: https://github.com/mariolukas/Watterott-CO2-Ampel-Plus-Firmware https://github.com/mariolukas/Watterott-CO2-Ampel-Plus-Firmw... [5]: https://esphome.io/ https://esphome.io/
IgorPartola 6y ago
FYI the particle sensor link to AliExpress from that page is broken.
JJMalina 6y ago
The Plantower PMS5003 PM Sensor is unavailable to ship to the US on aliexpress https://www.aliexpress.com/item/32944660534.html https://www.aliexpress.com/item/32944660534.html Do you know of another supplier that ships to/within the US?
- jeremywho 6y ago
  I'm looking for this as well. The only think I found was https://www.adafruit.com/product/3686 https://www.adafruit.com/product/3686, but thats 4x the price of aliexpress.
  - denimnerd42 6y ago
    https://www.aliexpress.com/item/4001039451614.html https://www.aliexpress.com/item/4001039451614.html
- phaedrus441 6y ago
  Did you search for "PMS5003" on aliexpress? I found a few suppliers, and ordered one for $15.81 with shipping (4.9/5 rating; 156 orders)
  - JJMalina 6y ago
    Good call, thank you!

azmodeus 6y ago

It would be nice if preassembled kits could be purchased from you. I would be happy to pay USD 40 for a good preassembled kit.

headmelted 6y ago
This. I no longer have access to a soldering iron and want a bunch of these, not enough that it's worth the cost of buying equipment and the time spent making them. Help us give you money! :-)
- joshmlewis 6y ago
  You can get good soldering irons for less than $100.
  - headmelted 6y ago
    Yeah but I have to buy the soldering iron then spend my time figuring the kit out and doing the job. I’d be happy to pay OP for their work and everyone wins.
cinntaile 6y ago
The BOM already costs more than USD 40 so USD 80 is probably a more realistic number for a preassembled kit.
- azmodeus 6y ago
  Would be happy to pay USD 80 for it as well
dmitriid 6y ago
Once you start assembling and selling these, you'll quickly realise why many things are priced the way they are. Especially low-volume tings like "pre-assembled DIY kits"
EricE 6y ago
Way too low for that - good rule of thumb is 1.5x to 2.5x the cost of materials for labor if someone else is going to do it for you.

shared_frog 6y ago

I appreciate your DIY instructions, but I really dislike how your website goes through the effort of hiding what you actually sell and also how much it costs. I don't want to "contact you" to get that information. We've been long enough in the 21st century that it has become an adult, and still I keep running into this archaic nonsense. For example, you mention your "sensor package" in the FAQ and that's it. Your DIY instructions mention the "AirGradient PCB", _but there is no place where I can buy it_. For the love of god, put a 'buy' button on your website.

Semaphor 6y ago
The PCB is not sold by them, they have the Gerber files for download, and you can upload them here [0] to have it made and shipped to you. It seems what they are selling are consulting services with possible parts depending on the results, if you don’t want to do everything yourself. [0]: https://jlcpcb.com https://jlcpcb.com
xwdv 6y ago
They want to change what they charge from time to time so putting a price up front will force them to leave money on the table. Not gonna happen. Contact them instead.
- bigiain 6y ago
  Instead of contacting them, I will spend a little time investigating whether there's someone else I can buy from, who doesn't consider being "forced to leave money on the table" makes this a reasonable way t treat potential customers, and will choose to spend money at a less customer hostile business - or possibly do without the product. Contacting some random "enterprise sales" team? Not gonna happen.
  - xwdv 6y ago
    What if they put an upfront price of $100 dollars but cheaper prices available if you contact them?

jsingleton 6y ago

It looks like you're using a Plantower PMS5003. I have one of those hooked up to a Raspberry Pi and it works well but I also built a few of these with ESPs: https://sensor.community/en/sensors/airrohr/ https://sensor.community/en/sensors/airrohr/ They support the PMS but I used the default SDS011. They both seem reasonable for relative values but I'm not sure about the accuracy without proper calibration. They don't appear to give similar readings to my Plume Flow 2: https://plumelabs.com/en/flow/ https://plumelabs.com/en/flow/

throwaway9d0291 6y ago

I've seen references to this sensor before and find it a bit concerning that there's no information about how to properly use the CO2 sensor. This sensor uses a SenseAir S8, which like most CO2 sensors, has an automatic baseline calibration algorithm enabled [0], which expects to see pure, undiluted fresh air at least once every 8 days. The only way to disable it is explicitly, through the MODBUS interface [1]. Leaving it enabled makes perfect sense in a business or businesslike environment because these environments will be completely unoccupied overnight and have air conditioning, which usually does a daily fresh-air purge, ensuring that the sensor will have regular exposure to fresh air. However in a residential environment, the auto baseline calibration often doesn't make sense, especially in winter. When the windows are closed and/or people or pets are around, it's very rare for the sensor to see uncontaminated fresh air, so it will see say 500ppm of CO2 and assume it's fresh air when it really isn't. I have measured this and it's a real problem. In a residential environment, unless you're sure you have good, frequent exposure to pure fresh air, you're better off doing a fixed calibration once a year or so. AirGradient also seems to be a hardware-only design. The ESPHome project [2] has great software support for a variety of sensors (including the SenseAir S8, so it should be compatible with the AirGradient hardware) as well as a very well-documented hardware project [3]. After trying my own Arduino-based software and then ESP-IDF, I find esphome much more pleasant to work with. [0]: https://rmtplusstoragesenseair.blob.core.windows.net/docs/publicerat/PSP107.pdf https://rmtplusstoragesenseair.blob.core.windows.net/docs/pu... [1]: https://rmtplusstoragesenseair.blob.core.windows.net/docs/Dev/publicerat/TDE2067.pdf https://rmtplusstoragesenseair.blob.core.windows.net/docs/De... [2]: https://esphome.io/ https://esphome.io/ [3]: https://github.com/nkitanov/iaq_board https://github.com/nkitanov/iaq_board

cleorama 6y ago
Is there a CO2 sensor (part) and/or a CO2 monitor (device) one can buy that is well-suited for residential spaces?
- throwaway9d0291 6y ago
  Any CO2 sensor (part) that gives you the ability to turn off ASC should work just fine and most of them do, you just need to trigger it. Personally, after trying out a bunch of sensors, I use the Sensirion SCD30. As for devices, I'm not aware of a consumer device that I'd recommend. If you're willing to do at least a little bit of DIY, Watterott [0] sells an SCD30 hooked up to an Arduino-compatible MCU with WiFi, a red/green/blue indication of CO2 levels and ASC disabled by default [1]. It's an open-source hardware design and software [2] and has a few reference firmwares [3], including one [4] for MQTT. If you want to go a little bit further, I'd recommend an ESP32 with an SCD30 and ESPHome [5]. That's what I use myself, mostly because I already had the sensors prior to Watterott's product existing. [0]: https://shop.watterott.com/ https://shop.watterott.com/ [1]: https://shop.watterott.com/CO2-traffic-light-Plus-version-Wifi https://shop.watterott.com/CO2-traffic-light-Plus-version-Wi... [2]: https://github.com/watterott/CO2-Ampel https://github.com/watterott/CO2-Ampel [3]: https://learn.watterott.com/breakouts/co2-ampel/ https://learn.watterott.com/breakouts/co2-ampel/ [4]: https://github.com/mariolukas/Watterott-CO2-Ampel-Plus-Firmware https://github.com/mariolukas/Watterott-CO2-Ampel-Plus-Firmw... [5]: https://esphome.io/ https://esphome.io/

IgorPartola 6y ago

FYI the particle sensor link to AliExpress from that page is broken.

JJMalina 6y ago

The Plantower PMS5003 PM Sensor is unavailable to ship to the US on aliexpress https://www.aliexpress.com/item/32944660534.html https://www.aliexpress.com/item/32944660534.html Do you know of another supplier that ships to/within the US?

jeremywho 6y ago
I'm looking for this as well. The only think I found was https://www.adafruit.com/product/3686 https://www.adafruit.com/product/3686, but thats 4x the price of aliexpress.
- denimnerd42 6y ago
  https://www.aliexpress.com/item/4001039451614.html https://www.aliexpress.com/item/4001039451614.html
phaedrus441 6y ago
Did you search for "PMS5003" on aliexpress? I found a few suppliers, and ordered one for $15.81 with shipping (4.9/5 rating; 156 orders)
- JJMalina 6y ago
  Good call, thank you!