4 ms·

I picked up a pair (indoor+outdoor) of https://www.airgradient.com https://www.airgradient.com monitors a few months ago. Happy with them so far though I have n

I picked up a pair (indoor+outdoor) of https://www.airgradient.com https://www.airgradient.com monitors a few months ago. Happy with them so far though I have not decided on their final positions.

tomek_ycomb 2y ago
Excellent information from the person(s?) running air gradient with regards to pm sensor tech and design. Blog posts, etc. Ranges of kits from pre assembled to solder-yourself, that HN might like. (I am happy with my unit I gave to a friend with a wood fire stove heated house, and built one from kit to save some $ another time.)
- ds_opseeker 2y ago
  I'll second air gradient. Founder is really cool and supportive. Tech works. I bought some boards from him a while back, ordered the parts of off alibaba, and had a working ESP32 setup in short order.
mtlynch 2y ago
I also own an indoor AirGradient, and I like supporting open-source, open hardware, but I've been pretty disappointed with the product. There were no instructions in the box, and I had to dig around a while until I found this PDF from three years ago.[0] I normally can figure out a gadget without reading instructions, but this wasn't self-explanatory, as there are no inputs on the device itself, and I had to figure out how to connect it to my WiFi. It's open-source, but there are no official instructions for re-flashing the device. I had to piece the process together from third-party blog posts. The code itself is pretty low quality. They use tons of globals that could trivially be local variables, and they throw away precision of floats by casting them to ints. I fixed a bunch of bugs in my fork[1] and started contributing them upstream, and the maintainer told me that they just did a giant rewrite, so I'd have to re-do all my changes.[2] I get that it happens, but I would have preferred they announce in the README that the code is deprecated and not to work on it until this rewrite is complete. I still think it's fine overall and I'd probably buy it again for other rooms in my house, but I hope they get their act together a bit more. [0] https://www.airgradient.com/documents/AirGradient%20Manual%2012APR2021.pdf https://www.airgradient.com/documents/AirGradient%20Manual%2... [1] https://github.com/mtlynch/airgradient-arduino https://github.com/mtlynch/airgradient-arduino [2] https://github.com/airgradienthq/arduino/pull/45 https://github.com/airgradienthq/arduino/pull/45
- ahaucnx 2y ago
  Achim from AirGradient here. I fully understand your frustration. Maybe a bit of background information to put this into perspective. Until around a year ago, the open-source DIY kits where a seperate 'side project' as we focused on our (now retired) closed source air quality monitors. However last year we decided to go fully open-source hardware and started to merge the closed source features into the open-source firmware. Because we needed a much better code base, a complete re-write was required (also supporting two different MCUs). So the last 6 months was really a transition period and things were a bit messy but I believe we have a much better onboarding and instructions [1] now available on the website and are continuing to work on it. [1] https://www.airgradient.com/documentation/ https://www.airgradient.com/documentation/
  - mtlynch 2y ago
    Hi Achim, thanks for the response! Would it be possible for you to document somewhere how to flash from source? The website currently kind of explains it under "Flashing Of The AirGradient Firmware," but step two is to flash the "ONE_V9.ino" file, but there's no explanation of where to get that file. I know it used to exist on AirGradient's Github[0], but now I don't see it anywhere after the v3 rewrite. [0] https://github.com/airgradienthq/arduino/blob/2.4.15/examples/ONE_V9/ONE_V9.ino https://github.com/airgradienthq/arduino/blob/2.4.15/example...
    - ahaucnx 2y ago
      It's now called "OneOpenAir.ino". We are still in the process to update the help files.
troydavis 2y ago
I bought an AirGradient indoor meter and ran into 3 significant undocumented problems, 2 of which affect CO2: 1. The VOC readings use a relative scale and it's relative to a floating value: the last 24 hours. If a VOC source is present for more than 24 hours, it will quietly become part of the baseline value (100). You can read more here: https://forum.airgradient.com/t/measurement-values-for-the-airgradient-one-tvoc-readings/1027 https://forum.airgradient.com/t/measurement-values-for-the-a... , https://forum.airgradient.com/t/measurement-values-for-the-airgradient-one-tvoc-readings/1027/13 https://forum.airgradient.com/t/measurement-values-for-the-a... 2. The CO2 measurements re-calibrate to the lowest value detected every week (as ~400 ppm clean air). If it's not exposed to clean air every week, the readings will drift. When users asked how this worked, calibration hadn't been thought about much, if at all: https://forum.airgradient.com/t/model-number-for-co2-calibration/1478 https://forum.airgradient.com/t/model-number-for-co2-calibra... , https://forum.airgradient.com/t/model-number-for-co2-calibration/1478/17 https://forum.airgradient.com/t/model-number-for-co2-calibra... 3. The graphs don't show reboots, even though reboots (always?) reset the baselines. Reboots happen relatively frequently due to software updates. So, even the relative scale can change without any entry on the graph. I was pretty annoyed because it didn't seem like the company had thought through the user experience enough to even encounter these questions, let alone consider the best implementation (or at least document the flaws in whatever they're able to implement). This is the whole purpose of the product. The company means well and tries hard, but at some point good intentions matter less than the product.
- ahaucnx 2y ago
  Achim, founder of AirGradient here. These are all valid points that came up at the beginning of the year and we took this feedback very seriously. I'm happy to let you know that we have implemented already point 1) and 2) in the latest firmware version. You can now set the "learning gain offset" for TVOC and NOx from the default 24h to basically 1 year. As a result the monitor will behave much more like an absolute TVOC monitor as the baseline reset is much longer. We have also implemented the automatic baseline calibration period, which you can now set to a much longer period than one week. We are also looking into feeding the last vale back into the sensor to avoid the reboot issue but this is more tricky to implement. By the way, if you compare the granularity that we offer now to fine tune the sensor modules, I'm not aware of any competitor offering the same feature set. But we won't stop here. We currently working on fine tuning compensation algorithms for PM.

I picked up a pair (indoor+outdoor) of https://www.airgradient.com https://www.airgradient.com monitors a few months ago. Happy with them so far though I have not decided on their final positions.

tomek_ycomb 2y ago

Excellent information from the person(s?) running air gradient with regards to pm sensor tech and design. Blog posts, etc. Ranges of kits from pre assembled to solder-yourself, that HN might like. (I am happy with my unit I gave to a friend with a wood fire stove heated house, and built one from kit to save some $ another time.)

ds_opseeker 2y ago
I'll second air gradient. Founder is really cool and supportive. Tech works. I bought some boards from him a while back, ordered the parts of off alibaba, and had a working ESP32 setup in short order.

mtlynch 2y ago

I also own an indoor AirGradient, and I like supporting open-source, open hardware, but I've been pretty disappointed with the product. There were no instructions in the box, and I had to dig around a while until I found this PDF from three years ago.[0] I normally can figure out a gadget without reading instructions, but this wasn't self-explanatory, as there are no inputs on the device itself, and I had to figure out how to connect it to my WiFi. It's open-source, but there are no official instructions for re-flashing the device. I had to piece the process together from third-party blog posts. The code itself is pretty low quality. They use tons of globals that could trivially be local variables, and they throw away precision of floats by casting them to ints. I fixed a bunch of bugs in my fork[1] and started contributing them upstream, and the maintainer told me that they just did a giant rewrite, so I'd have to re-do all my changes.[2] I get that it happens, but I would have preferred they announce in the README that the code is deprecated and not to work on it until this rewrite is complete. I still think it's fine overall and I'd probably buy it again for other rooms in my house, but I hope they get their act together a bit more. [0] https://www.airgradient.com/documents/AirGradient%20Manual%2012APR2021.pdf https://www.airgradient.com/documents/AirGradient%20Manual%2... [1] https://github.com/mtlynch/airgradient-arduino https://github.com/mtlynch/airgradient-arduino [2] https://github.com/airgradienthq/arduino/pull/45 https://github.com/airgradienthq/arduino/pull/45

ahaucnx 2y ago
Achim from AirGradient here. I fully understand your frustration. Maybe a bit of background information to put this into perspective. Until around a year ago, the open-source DIY kits where a seperate 'side project' as we focused on our (now retired) closed source air quality monitors. However last year we decided to go fully open-source hardware and started to merge the closed source features into the open-source firmware. Because we needed a much better code base, a complete re-write was required (also supporting two different MCUs). So the last 6 months was really a transition period and things were a bit messy but I believe we have a much better onboarding and instructions [1] now available on the website and are continuing to work on it. [1] https://www.airgradient.com/documentation/ https://www.airgradient.com/documentation/
- mtlynch 2y ago
  Hi Achim, thanks for the response! Would it be possible for you to document somewhere how to flash from source? The website currently kind of explains it under "Flashing Of The AirGradient Firmware," but step two is to flash the "ONE_V9.ino" file, but there's no explanation of where to get that file. I know it used to exist on AirGradient's Github[0], but now I don't see it anywhere after the v3 rewrite. [0] https://github.com/airgradienthq/arduino/blob/2.4.15/examples/ONE_V9/ONE_V9.ino https://github.com/airgradienthq/arduino/blob/2.4.15/example...
  - ahaucnx 2y ago
    It's now called "OneOpenAir.ino". We are still in the process to update the help files.

troydavis 2y ago

I bought an AirGradient indoor meter and ran into 3 significant undocumented problems, 2 of which affect CO2: 1. The VOC readings use a relative scale and it's relative to a floating value: the last 24 hours. If a VOC source is present for more than 24 hours, it will quietly become part of the baseline value (100). You can read more here: https://forum.airgradient.com/t/measurement-values-for-the-airgradient-one-tvoc-readings/1027 https://forum.airgradient.com/t/measurement-values-for-the-a... , https://forum.airgradient.com/t/measurement-values-for-the-airgradient-one-tvoc-readings/1027/13 https://forum.airgradient.com/t/measurement-values-for-the-a... 2. The CO2 measurements re-calibrate to the lowest value detected every week (as ~400 ppm clean air). If it's not exposed to clean air every week, the readings will drift. When users asked how this worked, calibration hadn't been thought about much, if at all: https://forum.airgradient.com/t/model-number-for-co2-calibration/1478 https://forum.airgradient.com/t/model-number-for-co2-calibra... , https://forum.airgradient.com/t/model-number-for-co2-calibration/1478/17 https://forum.airgradient.com/t/model-number-for-co2-calibra... 3. The graphs don't show reboots, even though reboots (always?) reset the baselines. Reboots happen relatively frequently due to software updates. So, even the relative scale can change without any entry on the graph. I was pretty annoyed because it didn't seem like the company had thought through the user experience enough to even encounter these questions, let alone consider the best implementation (or at least document the flaws in whatever they're able to implement). This is the whole purpose of the product. The company means well and tries hard, but at some point good intentions matter less than the product.

ahaucnx 2y ago
Achim, founder of AirGradient here. These are all valid points that came up at the beginning of the year and we took this feedback very seriously. I'm happy to let you know that we have implemented already point 1) and 2) in the latest firmware version. You can now set the "learning gain offset" for TVOC and NOx from the default 24h to basically 1 year. As a result the monitor will behave much more like an absolute TVOC monitor as the baseline reset is much longer. We have also implemented the automatic baseline calibration period, which you can now set to a much longer period than one week. We are also looking into feeding the last vale back into the sensor to avoid the reboot issue but this is more tricky to implement. By the way, if you compare the granularity that we offer now to fine tune the sensor modules, I'm not aware of any competitor offering the same feature set. But we won't stop here. We currently working on fine tuning compensation algorithms for PM.