This is very cool! I assume this is meant for outdoor placement; though in that case I'd wonder if the CCS811 actually has any point to being on there. (Detecting natural gas leaks, perhaps?)

And I do see data connections, so I presume that the information could be transmitted to an indoor unit (using other components) to check on current conditions. Am I right in that?

This was designed for outdoor placement, yes. Unless of course you want to measure the weather inside your house!

The point you bring up about the CCS811 is valid. It doesn't serve a large purpose when placed outside. As Xasin mentioned below, it may be relatively redundant when paired with the BME680.

With a little modification/connections, you should be able to connect this device to another to offload information. All the sensors and SD card on the board are wired to use the Feather I2C and SPI pins. You could use those pins and other available ones to talk to another device! 3 of the sensors (not the light sensor) currently use I2C, while the SD card uses 4-wire SPI. The board could be modified/redesigned to incorporate more SPI connections. Both the AS3935 lightning sensor and the BME680 sensor support SPI, I just did not design the board to use those communications. The CCS811 only supports I2C.

Thanks for the feedback and questions!

Yeah, I've been thinking of pulling together something similar, and having it communicate with my indoor systems (desktop PC and smartphone) via Wifi. There can be quite a difference at times between the airport weather station and my home (as much as 4 degrees in temperature, I've learned). But as long as the main processor can access all the data as it comes in, it should be able to send it out regardless of what protocol is used. (And hopefully not having the SD card in the holder won't keep it from working!)

Can I ask why you used a separate sensor for the VOC air measuring?

The system used in the BME680 is pretty similar, in that it has a MOX hotplate that gets cycled between hot and cold states to measure VOC content in the air.

Then again, I am wondering in what way the other sensor diverges, and if so, if different gasses can be recorded - that would be pretty neat.

Also, may I ask what the sensor cutouts are for? I'd guess thermal separation, but since there would be the FeatherWing base board below, radiating some warmth upwards, I'm still a bit unsure.

I see what you're getting at for the CCS811, it is kind of a redundant sensor. I honestly have not looked too extensively into the difference between it and the BME680 sensor. This board started as just another Featherwing board to make, but I'm starting to see that I might not have thought it through enough from the beginning. The CCS811 may have some functionality that the BME680 does not, but I'll have to do more research into it.

The sensor cutouts were initially designed as thermal reliefs, but I see what you mean about heat from the attached Feather flowing upwards and potentially affecting the readings. It would not work to have the Feather above the weather station, as that would affect the light reading.

Thanks for the feedback!

Maybe the ALS-PT9 could be placed at the end of the board, just past the antenna?

Potentially, but if the Feather is placed above the Featherwing, it will still overshadow the sensor. But that is a possibility if it needs to move.

Also, that antenna on the board, which currently does not have a 3D model, is just a 100uH inductor from Coilcraft that is designed for this lightning detector IC (https://datasheet.octopart.com/MA5532-AEB-Coilcraft-datasheet-17369798.pdf). It's been used in a Sparkfun board (https://www.sparkfun.com/products/15441) in the past, so it has been shown to work.

I should be uploading a BOM soon, which will list all the current components.

is the cutout between sensors realistically achievable? IIRC boardhouses go through that with the mill bit of 0.1 inch, so it might get tricky.

Honestly, I don't know. I was not thinking about that when I was building this the other day. That is a valid concern that I'll look into, thank you. I'll probably send the files through Advanced Circuits' FreeFDM (https://www.4pcb.com/free-pcb-file-check/index.html) and see what it has to say. That might give enough info.

If you have any resources or advice on how to check if this is achievable, feel free to let me know. I'm always open to suggestions/feedback!

I only became aware of this because @oshpark posted some articles on their blog about how to achieve certain things.  https://docs.oshpark.com/submitting-orders/slots/

I usually stick to 1mm or larger slots and it works out okay, for any of the main boardhouses.

One thing I'd recommend: Make the internal corners rounded. Endmills can't take out perfectly square corners, so the boardhouse will change your outline file. They might make the corners rounded, or they might expand them and that would be Bad. Better to specify yourself :)

I was thinking about that as well. What you said seems consistent with what I've found/heard elsewhere. Like you said, better to specify it myself!

Thanks for the input!