
Show HN: Enviro+ for Raspberry Pi – Environmental sensors - whiskers
https://shop.pimoroni.com/products/enviro-plus
======
josecastillo
Weirdly coincidental timing on this! I've been working on a PCB design
(FeatherWing form factor) to track weather data on my hikes, making use of a
BME280 and a GPS module. First revision of the board[1], I discovered that the
sensors started out accurate, then drifted up to a steady 3° above ambient.
Probably because the GPS module was heating up. So last night I found myself
reading up on design considerations for temperature sensors [2], including
specific things like the cutout you have on the left side of this board.

I'm guessing you designed this — any advice as I embark on designing a second
revision of my hiking log?

[1]
[https://twitter.com/josecastillo/status/1134128199972130816](https://twitter.com/josecastillo/status/1134128199972130816)
[2]
[http://www.ti.com/lit/an/snoa967a/snoa967a.pdf](http://www.ti.com/lit/an/snoa967a/snoa967a.pdf)

~~~
whiskers
Hi Joey - yes, this is one of our boards. :-)

Are you sure it's the GPS module - 3 degrees sounds a lot for that? I'd try to
take some measurements to confirm it before changing anything.

Which Feather board are you using?

~~~
josecastillo
I'd been planning to use it with the Feather M0 Bluefruit, but for now I'm
testing with an M0 Express with one of these LED displays next to it [1] on a
board doubler. Good to know that this is more temperature rise than you'd
expect to see; I'll have to confirm that (and measure the thing's current
draw, which I have not had a chance to do yet). Thanks!

[1]
[https://www.adafruit.com/product/3132](https://www.adafruit.com/product/3132)

------
m4x
This looks great. I've been waiting for a nice, hackable, cheap set of
environmental sensors!

There's only one "improvement" I would like to see - an option to buy a
cheaper version without a display attached. For my application I will not need
any display, and it seems a shame to spend resources on one when it's only
going to get destroyed by the elements :)

~~~
cf498
A raspberry is quite an overkill for an environmental sensor. You could
achieve the same with an Cortex M4 (minus the microphone).

~~~
m4x
Can you easily log to influxdb from a Cortex M4 though? That's the big benefit
of a RPi from my point of view

~~~
cf498
Havent heard of it before, but according to wikipedia they accept data input
over UDP in a minimalistic format, so I dont see how this would be a problem.

------
JoeDaDude
By an incredible coincidence, I am putting together something to do exactly
what this does. One exception: I am including a CO2 sensor to monitor and
collect atmospheric CO2 levels.

I'm guessing a there is enough I/O left on a Pi 0w such that a CO2 sensor can
be added to the Enviro+?

~~~
whiskers
Which sensor are you looking at? I'm sure it could run alongside the rest of
Enviro+!

~~~
JoeDaDude
The most likely candidate is the TelAire T6613 [1]. Like most sensors in this
price range, it reports data on I2C.

[1]
[https://www.co2meter.com/collections/0-1-co2/products/t6613-...](https://www.co2meter.com/collections/0-1-co2/products/t6613-co2-sensor-
module)

~~~
buildzr
Have you considered the much cheaper MH-Z19 or even the CCS811?

Doubt they're as capable or accurate but I'd be interested in hearing the
reasons behind going with the pricier sensor if you've got time to share.

~~~
JoeDaDude
Good question. My casual research into CO2 sensors is that they are generally
made for indoor air quality rather than outside atmospheric concentration.
Indoor CO2 concentration can soar as high as 1000 ppm where outdoors hovers
around the 400 ppm level, so it is important to get a sensor made for the
lowest range. The T6613 is specified for operation at 400 ppm so that is a big
driver for my decision.

The MH-Z19 has a model specified for 0 to 2000 ppm so it might work fine. I
don't know about the CCS811, the data sheet says it measures "equivalent" CO2,
which is not a direct measurement, but a quantity inferred after measuring
other compounds.

In the long run, there are calibration problems, as the photodetector ages.
The best sensors have two light sources and automatically compensate for this
effect. Indeed the other candidate I am considering is the Telaire 6615 which
has dual sensors. My plan is to use the one of the two Telaires, preferably
the dual sensor version, and correct measurements for temperature, pressure,
and humidity. Hopefully, it will be accurate for a long time without the need
for calibration with a known gas.

FWIW, I am just an amateur and welcome informed opinions. Scientific
instruments that measure accurately in the atmospheric range are too pricey
for me. The scientific community is just now starting to evaluate low cost
sensors like the ones mentioned here, see [1] for a summary of some recent
evaluations.

[1]
[https://www.wmo.int/pages/prog/arep/gaw/documents/Draft_low_...](https://www.wmo.int/pages/prog/arep/gaw/documents/Draft_low_cost_sensors.pdf)

------
zantana
I'm working on a similar nodemcu based system that was originally proposed by
Bruh Automation
[https://www.youtube.com/watch?v=jpjfVc-9IrQ](https://www.youtube.com/watch?v=jpjfVc-9IrQ)
later updated by digiblurDIY
[https://www.youtube.com/watch?v=9Yu57vjz7AY](https://www.youtube.com/watch?v=9Yu57vjz7AY)
to use ESPhome [https://esphome.io/](https://esphome.io/) with no progamming.

This looks interesting, but somehow it always seems wasteful to use full blown
Linux servers for this stuff, so I'm dabbling in something smaller. :)

~~~
whiskers
Sometimes a full Linux stack is a blessing but I totally understand where
you're coming from. :-)

~~~
zantana
It's just that I keep finding cool hats/phats like this that feel that way. :)
I'm wondering about the possibility of building a high latency Kubernetes
cluster to make use of the excess compute of some of the Raspberry Pis.

The HomelabOS project
[https://gitlab.com/NickBusey/HomelabOS](https://gitlab.com/NickBusey/HomelabOS)
is something I have been looking at. It would be neat if I could use a handful
of Pis across the house wasting cycles for something like that in a kubernetes
style fashion.

One other since you're the poster and presumably work at Pimoroni, is there a
preferred distributor in the US?

~~~
whiskers
I'm one of the co-founders of Pimoroni. :-)

Adafruit carry most of our range - hopefully they'll pick this up too soon!

------
prashnts
I love Pimoroni Modules, having used the MicroDot pHAT, Unicorn boards, Touch
pHAT, (and several more). The only problem I have is that the libraries aren’t
particularly well written. Of course they’re open source and I would like to
improve them, but as far as I know there are no schematics available.

Example being, the Touch pHAT (very good board btw) doesn’t use interrupts and
library is sorta messy. I still use it though, because it’s not a big deal —
however it’d be nice to be able to take full advantage of the components used
in the boards. I guess my rant is mostly about not having access to some
schematics of the products.

~~~
whiskers
We're working on opening up the schematics to our range, watch this space!

~~~
prashnts
Thank you! That’s all I needed, and of course I’ll contribute back the changes
I made to libraries (particularly the Microdot pHAT — which I love by the way
— just that the changes are not pretty at the moment...).

------
sam0x17
By coincidence I actually need this -- going to be doing some data analysis on
indoor hydroponics grow rooms and this would give me all the environmental
data I need if you include the particulate matter sensor.

~~~
woile
I was thinking the same, would be really nice for hydroponics!

------
jonathankoren
This is pretty cool. I’ve been looking to expand / replace PurpleAir with
something that monitored gasses in addition to particulate matter.

I don’t think this is exactly what I want, since it has an LCD, but the
sensors and board are really cool.

The only thing I wish this tracked was SO2.

I’m thinking i might have to make my own with Arduino. But this is very cool.

------
thisnews
I wonder how easy it would be to convert, or design something similar to the
Enviro+ that is in a waterproof enclosure with battery. Could be useful for
collecting data on some basic water quality(turbidity,conductivity,pH,temp)
alongside water level.

We currently use In-situ Aqua Trolls[1] to gather these parameters, but a
solution like this could almost be considered disposable; hand them out to
people in remote areas and you could potentially realise data for
rivers/creeks that rarely flow, and would otherwise go unmonitored due to the
time and finial investment required.

Very interesting project, thanks for sharing!

[1][https://in-situ.com/products/water-level-monitoring/aqua-
tro...](https://in-situ.com/products/water-level-monitoring/aqua-
troll-200-data-logger/)

~~~
joshvm
The trick with waterproofing is that it's easy to do rainproof enclosures, but
much harder to make fully submersible things.

For measuring water parameters I would be tempted to use a rugged box for the
Pi and then cable (via a removable connector) to something you put in the
water. Basically design a probe like the device you linked. The fewer parts
that need to be fully waterproof the eaiser life gets.

~~~
thisnews
Absolutely! There have been too many attempts by management to push our
technical team towards devices with replaceable batteries as a means of
reducing operational expenditure. Such loggers fail, often.

------
deanclatworthy
I was looking into some hobby sensors for home recently and came across this
the Ruuvi [1]. I prefer this model to having on-board sensors. This doesn't do
everything the Enviro+ does, but for a lot of use-cases it's pretty nice and
affordable.

[1] [https://ruuvi.com/personal/](https://ruuvi.com/personal/)

~~~
glogla
Do I understand it correctly that this doesn't store the data, and uses
bluetooth so you only see data for times when your phone was nearby, and on
iOS when the app was open?

That sounds kind of limiting. I guess every hacker has old smartphone
somewhere that can be used for that.

------
kmfrk
Was looking into something like this recently, but apparently a lot of the
sensors out there aren't super precise:

\-
[https://www.researchgate.net/publication/325416608_Suitabili...](https://www.researchgate.net/publication/325416608_Suitability_of_the_Low-
Cost_SDS011_Particle_Sensor_for_Urban_PM-Monitoring)

\-
[https://www.scientevents.com/proscience/download/potential-a...](https://www.scientevents.com/proscience/download/potential-
and-limitations-of-the-low-cost-sds011-particle-sensor-for-monitoring-urban-
air-quality/)

They are often easy to set up, but make sure to double-check just how much you
can use your particular model for.

------
polskibus
Are the sensors pre-calibrated? I found that you can easily get cheap air
quality sensors from China, the problem is that they could do better with
calibration, which may require expensive (in relation to the sensor itself)
equipment.

~~~
F_r_k
You can easily calibrate co2 , 02 and n2 sensors by going outside in a
"wild/nature" place

~~~
polskibus
Depends on the sensor, also full auto mode usually means (for example MH-Z19)
that it recalibrates every X hours, which means you'd have to go to the woods
fairly often ;)

~~~
gsich
can be disabled. But then I'd recalibrate them after a few months. (I do it
after 6 months usually)

~~~
polskibus
Which sensors do you use? Are you happy with them overall?

~~~
gsich
MH-Z14 and MH-Z19.

Yes, for the price absolutely.

~~~
polskibus
Are you using hass.io? Its plugin for MH-Z does not support switching auto
calibration off, and in not sure how to do it.

~~~
gsich
No.

------
Avamander
There have been just as comprehensive if not even more comprehensive sensor
sets available for a really similar price. It's nothing unique.

As building such boards is quite common, I too have assembled many similar
boards for my own use, to monitor both indoors and outdoors air quality
although I don't have any external stations to compare my values to but
they're "calibrated" according to the same baseline across my setup and it
allows me to keep an eye on different types of pollution - different gases,
particulates, UV, noise and so on. Would be nice if all these platforms could
be tied together.

------
FerretFred
Really looking forward to using this. Our local Council has a few air quality
monitors in strategic places and publish the results as open data. However,
they are 6 months behind in publishing data and have recently declared a "air
quality emergency". They also state "Currently the level of interest in air
quality appears to be rising, but this does not seem to translate into
interaction between the Council and the local communities".

With an Enviro+ on a portable Pi I'll now be able to get my figures in near
real time and ignore the Council.

------
darkhorn
Very similar to Pioneer600, an expansion board for Raspberry Pi.
[https://www.waveshare.com/pioneer600.htm](https://www.waveshare.com/pioneer600.htm)

~~~
mey
A quick look over the Pioneer600, the pressure sensor seems to be the only
overlap in the environmental monitoring that the Enviro+ is going for. The
Pioneer seems to be a utility board, great for messing around. To me they
would serve different purposes.

------
alfozan
I have been using [https://getawair.com/](https://getawair.com/) (2nd edition)
for over 6 months and I can't recommend it enough.

------
addicted
Any reason why the particulate matter sensor cannot be used indoors?

~~~
joshvm
No, it's just an aspirated dust sensor. No reason you couldn't run it inside.
The main reason they suggest outside is so you can contribute to a global air
quality database of some kind.

------
fiftyacorn
Ive been thinking about environment plugins for the raspberry pi for school
projects to measure polution - so might have a look at this

------
atonse
This is amazing. I'm going to add this to a fun weekend project to monitor air
quality in my neighborhood.

~~~
whiskers
Let us know how you get on!

~~~
atonse
I also passed it along to some contacts in the DC government. I told them this
is exactly the kind of stuff they should deploy all over the city to get air
quality, and just try it out since it's cheap enough to experiment with!

~~~
whiskers
Thanks!

------
spearo77
Is the alignment of the connector pads along the edge of the card deliberately
not straight?

~~~
frabert
It aids in soldering, as the header you put in stays put straight instead of
falling over or bending

~~~
spearo77
Nice. I definitely hit that problem, but never thought of that solution!

------
Ductapemaster
Does anyone know where I can buy one of those displays? Looks amazing for the
size and it has a standard connector instead of the weird hot-bar solderable
ones on the other small displays I have seen.

~~~
whiskers
We sell a breakout here: [https://shop.pimoroni.com/products/0-96-spi-colour-
lcd-160x8...](https://shop.pimoroni.com/products/0-96-spi-colour-
lcd-160x80-breakout) :-)

------
matmann2001
Anyone have experience making an enclosure for something like this to use
outdoors? Thinking of like a Stephenson screen with a built in solar panel for
powering the Pi + Hat.

------
laacz
I'd suggest breaking out this board to decouple it from rpi, since rpi heats
up enough to make temperature readings from attached board inaccurate.

------
ones_and_zeros
I don't know anything about Pis, though I've seen one. How does this attach?
Does it require soldering?

~~~
soneil
yes/no. it's sized to match the Pi Zero, which by default comes with no
headers - so to add this board you'd need to add headers. But many vendors
(including OP) offer them pre-soldered, which makes the hardware side "plug
the top bit into the bottom bit".

(The zero is positioned as the "barest of bare-bones" to reach its price-
point. Many vendors look for value-adds they can offer because there's not
much margin on "barest of bare-bones". So "no headers" is one of the ways the
manufacturing price was lowered, and "with headers" is one of the value-adds
some vendors offer.)

So not to contradict anyone, just to be clear that you're looking for "pre-
soldered" or "pre-soldered headers" if that convenience is worth the extra
couple of bob to you - to avoid the disappointment of expecting one and
receiving the other.

~~~
whiskers
This product works with any model of Raspberry Pi - it doesn't have to be a Pi
Zero!

The Pi Zero comes in three flavours - the Pi Zero WH includes a pre-soldered
header. :-)

~~~
soneil
ah, I didn't realise it was actually coming out of the fab like that now? I
could have sworn that at least initially, it was being offered as a value-add
service.

Anyway, I should stress it wasn't a criticism - just that if that's their
biggest question, they'd probably benefit from being able to tell the bare &
WH boards apart.

~~~
whiskers
Initially it was, but now there is an official SKU for pre-soldered header.
:-)

------
orion138
Are the schematics available?

Looks great!

~~~
whiskers
They will be!

~~~
orion138
I just put one on order :)!

Any idea when the PM sensors will be back in stock? I was thinking about
grabbing one from elsewhere, but I imagine I need a cable pinout :)

~~~
whiskers
Hopefully about a week!

------
xmichael999
Is there a case option?

~~~
whiskers
Obviously for the sensors to work they need to be exposed to air. We have a
tutorial coming next week on how to make a low-cost enclosure for use outdoors
- is that what you mean?

~~~
vinayan3
Yeah it'd be great if there was some kind of enclosure and holes / open spaces
for the sensors.

Even better if there was a combined case which let you have the Raspberry Zero
and this unit in one small thing.

