[werk_ag]

I put myself the question length of the cables.
For SHTxx, I believe that one can have +/- 1m wire without problem.
For the PMS7003/MH-Z19, I did not find information. With is your opinion 1 m of wire good?

The cables for the PMS7003 and MH-Z19 should be very short, no more than 15cm.
In the case of the PMS7003, don't extend the cable that comes with the adapter, just cut it at one end and put a suitable set of male female connectors. Pin headers like the ones in your picture are perfect.

Regarding the SHT31, yes, the cable can be longer (with a twisted par cable), but its preferable to have it near the other sensors.

[werk_ag]

Hello Werk_AG,

I need some infomations about parts not mentioned in your part list :

1. C1 and R1 also the fan control D1, R2 and T1 are only needed if you use a Sharp sensor.
2. R12 (value 0R on the shematics 5K?), C4, C5 and IC3 for AREF.

Pierrelux

Hi Pierrelux,

Yes, that's right. All those parts are only needed for the SHARP version. The AQM board is supplied with all the parts needed to work with the PMS7003, already installed.

Regards

[tobyportugal]

Good evening,

Thank you Werk-_AG.

If that perhaps useful, I received the PCB this afternoon, it is sometimes difficult to have an idea.
Here a photograph with Iphone SE - the PCB - a sensor t° Davis.
I think that the establishment in a Davis 7714 does not pose a problem.
By making an assembly off-sets for the antenna, more problem to lengthen the sons.

Good evening with all.

[werk_ag]

By making an assembly off-sets for the antenna...

Don't worry to much with the antenna. Start by just using a 17cm isolated wire, welded on the central pin of the Ant connector, most of the times this works great.

Also, do an analysis of the places outside your house for a possible installation. If you have a shaded well ventilated place, it will be a good location, and can turn assembling a lot easier. Just install everything, (electronics and sensors) inside a plastic case, and do some large venting holes per example at the bottom of the case or on the sides, depending on the position how the case will be fixed.

[Barrow4491]

Werk,
As I understand your post it is ideal to have the sensors and pcb in a common radiation shield (because of cable length restrictions) and somehow supply 9 v to the unit.
I can achieve this and am considering a "clear-coat" to protect the pcb from corrosion etc; do you have any recommendations?
Regards
Jim

[AllyCat]

Hi,

... the Zdeneck assembling can be one of the best possible solutions. Everything installed inside a structure similar to a radiation shield. This approach also have the advantage of providing good conditions for the Temperature / Humidity sensor.

- ... the readings from the sensor are also transmitted to the RX unit, acting like a Davis extra sensor. By default its mapped to extra sensor 6...

You didn't mention the height above ground to mount the assembly, but (for obvious reasons) I believe it normally would be at about  "head height" (~1.5 metres), similar to the primary weather T/H sensors.  Of course sometimes a different height may be needed to keep away from "human influences",  or perhaps that's what some might want to measure (vehicle exhaust, etc.).

Going a little Off Topic:  For my (urban) location, one of the advantages of the Weatherduino concept is that the Solar sensors can be mounted "up with the wind sensors" on a mast and / or "on the roof", sharing a Transmitter board.  So the only "missing" low-level meteorological measurement from the AQM is Rainfall (if there are no no leaf / soil wetness requirements).  Therefore, in the longer term, might it be possible to add a "Rain" input capability to the AQM, so that the present (low level) "Transmitter" board could be omitted (or moved up to "Wind/Solar" duties)?

Of course there are complications, for example in defining which are the "primary" and "extra" sensors.  Also, the Nano might be "sleeping" to save power, but the Rain signal is only a simple and infrequent pulse and there do appear to be spare Nano interrupt inputs.  The AQM sensor(s) might add some local heating to the enclosure, but then there is a "free" fan to give some Aspiration.

Personally, I would like to support an "extra" Rain sensor, although I don't know how (or if) this might be "managed" with the Davis protocols.  A few years ago I purchased a Hydreon RG11 rain sensor, when it was being discussed on the Sandaysoft forum here and here.  Generally, its optical method is not as accurate as a tipping bucket in good conditions, but it is more sensitive, particularly faster in detecting the onset of rain.  It's also ideal for "difficult" and remote sites, being immune to falling leaves (blocking the funnel) and the notorious spiders of tipping bucket sensors.  Unlike most tipping buckets, it does need a small power supply (preferably 9 volts, but 5 volts can be used) which fits well with a the Weatherduino concept.

Thanks,  Alan.

[Palmyweather]

Continuing the questions about the Air Quality Monitor:

• What is the current draw (amperage) of the final released board while it is running?
  
  
• From the parts list, the Air Quality Monitor requires a 9 Volt, 1 Amp power supply to drive the board. Will this current draw make it impractical to run on a 12V solar set up with appropriate voltage regulators?
  

I do not think this has been discussed in a public forum since the board has been released and thought it might be useful to discuss this aspect as well.

Kind regards,
Palmy Weather

[werk_ag]

You didn't mention the height above ground to mount the assembly, but () I believe it normally would be at about  "head height" (~1.5 metres), similar to the primary weather T/H sensors.  Of course sometimes a different height may be needed to keep away from "human influences",  or perhaps that's what some might want to measure (vehicle exhaust, etc.).

Hi Alan,

I also agree that (for obvious reasons) an Air Quality Sensor should be placed around the "head height". Mine is placed 2.0 meters above ground level.
I talked about put it away from "human influences",  exactly because some locations may suffer from an excessive of these influences, ex: a place where the people go to smoke, near a garage, etc, etc

Going a little Off Topic:  For my (urban) location, one of the advantages of the Weatherduino concept is that the Solar sensors can be mounted "up with the wind sensors" on a mast and / or "on the roof", sharing a Transmitter board.  So the only "missing" low-level meteorological measurement from the AQM is Rainfall (if there are no no leaf / soil wetness requirements).  Therefore, in the longer term, might it be possible to add a "Rain" input capability to the AQM, so that the present (low level) "Transmitter" board could be omitted (or moved up to "Wind/Solar" duties)?

Of course there are complications, for example in defining which are the "primary" and "extra" sensors.  Also, the Nano might be "sleeping" to save power, but the Rain signal is only a simple and infrequent pulse and there do appear to be spare Nano interrupt inputs.  The AQM sensor(s) might add some local heating to the enclosure, but then there is a "free" fan to give some Aspiration.

I think I understand what you mean, but wouldn't be preferable keep the AQM as a independent device? I think so. One possible problem I see, is combining the code of the AQM and the code of TX (even if only for the rain gauge) in the same Nano.
Only the array to allow having a 24h rolling average of the PM25 readings, with just a sample at each 15 minutes, takes around 20% of the 2K Nano memory (96 entries x 4 bytes, - each entry need to be long type).

Personally, I would like to support an "extra" Rain sensor, although I don't know how (or if) this might be "managed" with the Davis protocols.  A few years ago I purchased a Hydreon RG11 rain sensor, when it was being discussed on the Sandaysoft forum here and here.  Generally, its optical method is not as accurate as a tipping bucket in good conditions, but it is more sensitive, particularly faster in detecting the onset of rain.  It's also ideal for "difficult" and remote sites, being immune to falling leaves (blocking the funnel) and the notorious spiders of tipping bucket sensors.  Unlike most tipping buckets, it does need a small power supply (preferably 9 volts, but 5 volts can be used) which fits well with a the Weatherduino concept.

If the output of the Hydreon RG11 produces a pulse per each tip, I think you could use it with the WeatherDuino. The Rain Gauge connector on the TX board doesn't have the 5V or 9V available, but you can easily get any of these voltages from some points on the TX board, and wire it to one of the two unused pins of the Rain Gauge connector. Then its just a matter of defining in the software the rain value corresponding to each pulse. Hope I'm not saying anything wrong.

[werk_ag]

Continuing the questions about the Air Quality Monitor:

• What is the current draw (amperage) of the final released board while it is running?
  
  
• From the parts list, the Air Quality Monitor requires a 9 Volt, 1 Amp power supply to drive the board. Will this current draw make it impractical to run on a 12V solar set up with appropriate voltage regulators?
  

There is something about this some topics above, but let's add some details:

Its hard to say exactly what is the average consumption of the AQM board, but it can perfectly be powered trough a solar system.
I will try to give and idea for a system with the PMS7003 + MH-Z19, RF transmitter, without LCD display.

- There will be a fixed consumption of around 120mA. 60 mA for the Arduino Nano plus 60mA for the MH-Z19 (it don't have any sleep mode, its always working)
(In the future, its possible that I implement some Arduino power save features)
- Each 37 seconds, during transmission of the RF signal (less than a second), consumption will increase 30mA.
- At each 15 minutes, during the time (40 seconds) needed to read the PMS7003, the fixed consumption increases 100mA. After each reading the PMS7003 is putted in sleep mode (consumption <= 200uA) until the next reading.
- During the time (few seconds only) needed to read the MH-Z19, the fixed consumption will increase 80mA.
The two sensors never are read at the same time.

So, the maximum peak consumption for the configuration described above will not exceed 400mA.

[Palmyweather]

That is good to know, thank you Werk. Gives me some ideas on what I might try to do  

Kind regards,
Palmy Weather