AGP30, issues with CO2 VOC sensor

OK, nevermind, we figured it out, the sensor was OK. We've been flashing a bright LED every 5 seconds, as a heartbeat, visible in sunlight, and this was resetting the sensor.

Also, note that you need a baseline calibration in clean air, or it cannot detect ?dirty? air

Cheers

Klaus

Yes, we're saving and bringing back the cal values. May I ask, how important is the humidity correction? It's a painful to do the absolute humidity conversion formula in an ARM M0 processor, without floating point.

I did not dig into the humidity effects on this sensor. Not much is written about the compensations, so I guess the effect is minor

Cheers

Klaus

Just table-lookup it to death? You should have a lot of flash for detailed data, no?

Alan Stern, the Institute mathematician, who did all the programming for the beehive monitor, including the 14-sensor TH-stick, which includes the AGP30, tells me the floating-point libraries work just fine, but it's just slower. We do have the time, but maybe with all the huge masses of code he's written, he's running out of motivation to add more complication.

Winfield Hill wrote in news: snipped-for-privacy@drn.newsguy.com:

Add more cores.

We're only using an ARM M0, and could chose an M4, etc., if we had placed the controller on the mobo. But the PCB didn't have room; we needed the extra space obtained by using an Adafruit Feather.

Winfield Hill wrote in news: snipped-for-privacy@drn.newsguy.com:

Use one of these to drive it...

Nice Raspberry Pi replacement, but pretty big, 85mm x 56mm, or 102mm x 69mm. The feather is only 50 x 22mm. The width of my board is 24mm.

Winfield Hill wrote in news:qstres01r62 @drn.newsguy.com:

Well, that is hardly what that is. Compared to the pi, that is full bore professional level gear.

It depends on how many you are doing, who is paying, and how long you want them to last in the field. The price differential is not that much if it is funded in any way.

That is because it is not as you describe. It is an order of magnitude more than a Pi.

Is this not for bee hive management?

If so, one would think that a lot of module 'real estate' would be available.

Yeah, it is overkill. You could probably use one, and pipe data from all the hives to a single unit and run a weather station on top of that and plot the data out on a 4K display. Way more than needed here.

I guess transducer placement matters too. Or for absolute, maybe take readings from a few transducer installations and resolve each and then average those.

torsdag den 12. december 2019 kl. 16.52.38 UTC+1 skrev snipped-for-privacy@decadence.org:

you want to replace a $1 M0 mcu with a $100 A9 running linux?

in what way does that make any sense?

There's no operating system running on the Feather, so we combine data from multiple Feathers, to files in a Raspberry Pi, and thereby get internet access.

Lasse Langwadt Christensen wrote in news: snipped-for-privacy@googlegroups.com:

How is a Pi a "$1 MO mcu"?

Lasse Langwadt Christensen wrote in news: snipped-for-privacy@googlegroups.com:

Acoording to you? Price alone.

But hey, if you are unable to see the differences between those units and a Pi, then you are going senile or never had it and need new or remedial schooling or LSD or something, because you gotta be dumb or blind or both not to see that boy.

torsdag den 12. december 2019 kl. 19.26.34 UTC+1 skrev snipped-for-privacy@decadence.org:

I can see the differences, higher price, less performance, less memory. so ..

The Feather we are using has an Atmel ATSAMD21G18, ARM Cortex M0+, which is about $2.50 on Octopart. But I have seen Atmel's ARM Cortex M0 under $1.

Win,

Can the programming specifications of the sensor be found somewhere?

Yes, it's on the datasheet, plus more info at Sensirion,