The final version of the boards contains few notable improvements

1. Removed the PCB under the ESP8266 antenna. The previous design had PCB + Ground Plane, which resulted in VERY low reception. It worked just few meters away from the router.
2. Removed the Temperature Probe - On the one hand - it does not really measure real temperature, on the other hand it populates the Single Analog port, and makes it unavailable for other usages
3. Added place for an optional LDR (in case the Analog port is not used - one could add an LDR for added value)
4. The connection between GPIO 16 and RST (Deep Sleep) is not bridged via a 0603 0ohm resistor (jumper). Depending on application it may be enabled or not
5. Added a Power 5V line. That is - controlled via a SOT232 mosfet and one GPIO. This way you can connect power hungry modules and then turn them on or off. There are small mosfets rated ~ 2-3 amps for couple of cents.
6. The big 12mhz crystal for the CH340G was replaced by a small patch ceramic oscillator to save space
7. Added an additional mounting hole
8. Added additional test pads for the unused GPIOs
9. Added one Diode in series with the power to the WS2812B LED. It turned out, when powered directly via a USB Battery bank, the voltage can be 5.30-5.40v. And apparently WS2812B, does not light if VIN is > 5.15V. So putting a generic small Diode would drop 0.3-0.4V

Here is how the latest design looks like

The final version of the boards contains few notable improvements

1. Removed the PCB under the ESP8266 antenna. The previous design had PCB + Ground Plane, which resulted in VERY low reception. It worked just few meters away from the router.
2. Removed the Temperature Probe - On the one hand - it does not really measure real temperature, on the other hand it populates the Single Analog port, and makes it unavailable for other usages
3. Added place for an optional LDR (in case the Analog port is not used - one could add an LDR for added value)
4. The connection between GPIO 16 and RST (Deep Sleep) is not bridged via a 0603 0ohm resistor (jumper). Depending on application it may be enabled or not
5. Added a Power 5V line. That is - controlled via a SOT232 mosfet and one GPIO. This way you can connect power hungry modules and then turn them on or off. There are small mosfets rated ~ 2-3 amps for couple of cents.
6. The big 12mhz crystal for the CH340G was replaced by a small patch ceramic oscillator to save space
7. Added an additional mounting hole
8. Added additional test pads for the unused GPIOs
9. Added one Diode in series with the power to the WS2812B LED. It turned out, when powered directly via a USB Battery bank, the voltage can be 5.30-5.40v. And apparently WS2812B, does not light if VIN is > 5.15V. So putting a generic small Diode would drop 0.3-0.4V

Here is how the latest design looks like

@epierre said:

I had the contact with this seller, but an international money transfer was needed and is expensive...

yeah, they also have a minimum order quantity and ship with DHL only, so you have to pay import taxes to EU
so it only makes sense if you order a big quantitiy and then try to resell it somehow
all in all a hobby that at least has some return on investment, compared to other ones i had :))

You're courageous th have gone on kickstarter, from memory seeedstudio nearly went down because of an error on a crowdfunding project and had to produce and ship (the more expensive par of it) a remlacement for the first batches...

ahh .. i didnt know this about them... and in their scale - i can undertand
it happened to me as well but in my scale it was rather a paid lesson :))))

@alexsh1 said:

Which sensor are you using for dust?

I plan to use this one: http://www.gassensor.com.cn/product_detail_en/Particle_Sensor/PM2005
It is around 35-40 eur from the manufactuer, but somehow i tried some cheaper ones that were not laser based and i got random results

Regards, Vladimir

Hi Alex,

yes, we did
I am doing few things in parallel and eventually at some point of time (hopefully soon) i will have a complete offering
What exactly do you mean with "other options that you can complete yourself" ?
The simplest option is to get some ESP8266 evaluation board and connect some sensors to it - using jumper wires or soldering them somehow.

This is rather for prototyping, so i plan to extend my vESPrino project, with some dedicated adapter board, where one could fit some common sensors, (pir, lux, uv, what else ?) and the firmware would recognize them. It is not as good as an integrated solution, but could quickly solve some sensor defficiencies and not look too prototype-ish.

For CO, what is your use case? Of course i can create some device that integrates one of those sensors, but since CO is a dangerous gas, what would happen if for some random reason the device had failed, or wifi was down, and you relied on it telling that CO has risen? I do not want to take responsibility for this of course So if you do not rely on it for the main CO protection - then it is fine..

For Air Quality and VOC gases, i have both few months ago 100 units of TGS8100, which looks like an AQI sensor similar to the ones from SGH. I hope in the next couple of months to be able to create some breakout board so this one can be easily integrated into devices, and then create a device and driver for it.

Eventually at this point of time i could offer a monitor that has both - CO2 and AQI

And last but not least, measuring the Dust levels seems also to be important, especially in the winter, when the outdoor air is too poluted (though usually you can smell it ). But also for indoor dust monitoring this is important. In fact - this i can add even today.

Regards, Vladimir