AirGradient Forum

New AirGradient DIY Kit Version 3 Feedback and Discussion

#16

As someone that just built one of the current DIY kits I have a few comments.

I like the idea of a better case. I was unable to get a good print for the temperature sensor extension.
I like that the components will not need to be stacked.

I did like the breakout holes on the older board, but they didn’t have proper spacing, so the headers included in the kit could not be used.
I tried the SPG30, but had problems getting readings from it (as others have mentioned in the forum). I swapped it for a Bosch BME688 (adafruit module) which seems to work fine.

From the pictures, there don’t seem to be vents on the sides where the CO2 sensor goes. Cross air flow might be nice and not really impact the case look (maybe your engineering has shown it not necessary).
I would like the LED lights/bar to either be optional or software controlled so it can be turned off. Personally I think the OLED communicates enough without being distracting.

Looks good.

#17

Good points with the breakout pins and proper spacing.

Our enclosure was designed to create a chimney air flow in order to get the most accurate readings at the bottom of the enclosure where the temperature sensor is located. We experienced with side vents but that did not bring any additional benefits.

We also looked at the BME680 but found it to substantially overstate the temperature. Did you compare your readings to a reference thermometer?

#18

One other small bit of feedback, is it perhaps possible to design the board with onboard temp, humidity, and VOC? As in actually part of the main board instead of using modular sensors?

I know that means assembly then becomes just the Wemos, LCD, and PMS.

I’m also aware that removes the ability to change the sensors easily, and may conflict with the idea of “DIY”, so perhaps a bit controversial, but if the sensors were positioned for accuracy perhaps people wouldn’t be interested in using different kinds of sensors if the readings from the onboard sensors “just work “

#19

@brianFromNyc I used the PMS5003T on my build which also measures temperature and humudity. The PMS5003ST can measure temperature, humidity and VOC. The only “issue” is the price. The cheapest I could find, was maore than double the price of the PMS5003. The PMS5003T is slightly more expensive but cheaper than the PMS5003+SHT31.

1 Like
#20

I am running with both the SHT30 and the BME688. Here are some comparisons:
2 days

2day
2day1625×380 57.4 KB

1 hour

1hour
1hour1623×380 36 KB

I have not compared these values to a reference thermometer yet.
The BME688 values are using the “compensated” temp and humidity values. I haven’t looked at the “raw” output yet.

1 Like
#21

Another question regarding the new enclosure just popped up in my head:
Do the (two horizontal) mounting holes of the new case by any chance have the same spacing as the current case? This would prevent me and others from having to drill new holes for a wall mount. I realize that this might not be a big deal for some people but since I currently live in a rented apartment with no clue about what’s inside the walls, I try to keep my drilling activities minimal.

#22

It looks like the BME is consistently higher than the SHT which is similar to our observation. It would be great to see the comparison to a reference thermometer if available.

#23

it will have different spacing but the new enclosure should fit above European and US junction boxes and the spacing of the screws should just fit to these junction boxes.

#24

Mounting the SHT and TVOC sensors directly would probably not make much difference from soldering a module on the same spot. However it is something we look into in case we will offer a pre assembled kit.

#25

I can’t speak for all users, but personally I use AirGradient so I can get data into Prometheus. The DIY portion for me is because it’s the cheapest way, and I have the skills for both programming the Arduino and soldering the kit.

If there was an affordable way to get accurate air quality data into Prometheus, for instance a preassembed Wemos or Lolin D1 with accurate sensors, I would use that instead. Bonus points if it functions as a Prometheus metrics endpoint without me having to flash it.

#26

I like the look and the optional headers for other sensors. I’m on board!

#27

Thank you for the valuable feedback.

I want to share with you an update on the DIY v2 design.

I incorporated the following:

  • added the breakout pins (now compatible with 2.56mm pin headers)
  • added a Bosch BME sensor slot
  • added a slot for the bigger OLED display either on the front or backside
  • added a 2nd PMS connector that fits the standard cable
  • improved the naming conventions
  • flipped the S8 sensor to have the air intake on the top (in line with the recommended mounting direction)

I experienced with the ESP32 mini but it is difficult to get it placed inside the enclosure also due to the cable coming out of it that needs space. So at the moment, I believe it’s better to stick with the ESP8266.

Here is the current layout.

image
image976×1031 77.4 KB

I am also running temperature measurements against the old DIY enclosure / PCB (without the external temperature probe) and you can see that we are now only 0.3C above ambient air temperature whereas the old enclosure is 2.0C above.

image
image1809×1074 83.3 KB

I will keep you posted. If you have any further feedback, questions or ideas please let me know.

6 Likes
#28

I love all of this!

Having the breakout pins be compatible with regular headers will be a very welcomed improvement
I like the option for the PMS that fits the standard cable. Will your kits have the option to have a socket that could be soldered to the board, or will that be up to the DIYers?

#29

Not sure what you mean with cable as the ESP8266 also has the charging cable. Have you looked at the Wemos S2 mini? It has the same size as the Wemos D1 mini currently used but is an ESP32 S2. According to the documentation it is also compatible to the Wemos D1 mini shields. So it might be a simple drop-in replacement.

The new housing seems to be big enough to potentially also add a battery and a TP4056 Lithium Battery Charger and remove the need for a constant power supply. Assuming that no OLED or LEDs are installed at the same time.

1 Like
#30

I have another question/remark regarding the screw holes of the PM sensor:
While assembling my current kit, I noticed that the PCB has 1.7mm screw holes but the PMS5003 uses M2 screws according to its datasheet. Is there a particular reason to make the screw holes smaller than the screws? I first had trouble to get M2 screws through them and ended up extending the holes to 2mm.

Depending on your answer, maybe this could be addressed in version 2.

#31

Yes, it is already addressed. Screw holes will fit M2 screws on the new PCB.

2 Likes
#32

The ESP32 S2 is considerably wider because it has two additional pin rows. The cable management is not simple because the sensor needs to be placed in a way that avoids any modules and has enough length to bend.
Yes, I foresee a battery option. The new PCB has a mirrored D1 slot that can fit D1 shields. There is a battery charger shield that can be used on that slot and then connected to a battery. I have experienced with this and it should work well.

1 Like
#33

Hi,
May I ask you what’s the size of the European wall junction box you’re talking about?
It would be awesome to just add the whole kit upon an existing box!

But I do agree with @lbhm and his point… isn’t it possible to have more mounting holes on the back? The ones compatible with the current gen’mounting holes, and the ones compatible with European/US wall boxes?

I wholeheartedly love the LED strip idea, but agree with the possibility to switch it off completely (together with the OLED display) either via software during night times or manually with a side switch/button!

Would that be possible?

Thanks,
With love,
L.

EDIT1
The battery idea is lovely… would that create heat problems?

1 Like
#34

Is it possible to include detachable legs to support the enclosure in the verticle position? I move the unit around within our house and it would be handy.
Thanks, Doug

#35

This looks great :slight_smile:

What’s the timeline around this? Will there be a beta phase?

Really excited and keen to have a go at building a v2 kit :slight_smile:, and add one vote for vertical stand configuration.

Thanks