Weather Station Ideas

[Gina]

I have a design for an Arduino based weather station but the problem is communicating the data indoors.  Previously I have used a cable connection but have the cables eaten by rats.  The ideal solution would be WiFi and from my experience with astro imaging, the Raspberry Pi would seem to be a much better solution than Arduino.

There are a couple of things that rely on Arduino libraries which will need either libraries for the RPi of a rethink.  These include 1-wire which I think may be supported but also the Arduino design uses the Melexis MLX90316 rotary encoder chip for the wind vane with Arduino code and don't know if there's RPi code for it.  OTOH I'm not entirely happy with this chip and considering other ways of measuring the wind vane angle.

Edited June 28, 2020 by Gina

[Chriske]

Does it need to be that accurate to use an encoder..?

[wormix]

Watching with interest as this is something I’ve been considering for a while. 
 

Was just going to copy the Official Pi one With off the shelf parts but be interesting to see your approach. 

[pete_l]

I have a wh3080 weather station that is powered from a solar cell + battery, so it's a case of "look dad, no wires!". It transmits on 433MHz and has been operational for many years, now.

It seems to me that this is a good solution. You have to be frugal with the power requirements so an Arduino would have to sleep a lot and I doubt a Pi could be configured to work like that, Having said that, the amount of processing required is very small. So even an Arduino might be overkill.

Edited June 23, 2020 by pete_l

[Gina]

1 hour ago, Chriske said:

Does it need to be that accurate to use an encoder..?

No it doesn't.  8 or at most 16 angle slots would be fine.

[Gina]

Thinking "out of the box" maybe the way to go is to have very simple transmitter units and collect the data indoors.  Hence I have changed the title of the topic.

Many years ago I used the Maplin weather station with my own modifications to overcome some of the problems.  In fact I got through two sets as they didn't last very long.  That used a 433MHz RF transmitter as I recall.

I thought of using the RPi as I have plenty of experience of using these with my astro projects and KStars/Ekos/INDI software.  Modifying the C++ code to expand INDI drivers to cater for specialised features is no problem to me.  The Arduino code is similar but the Arduino doesn't have WiFi.

 

[Gina]

I wasn't originally thinking of using low power systems as power is available at various locations around the property in sheds and similar.  Power supply to the electronics could be protected in conduit.

[Gina]

I plan to collect the following data :-

• Wind direction
• Wind speed
• Temperature
• Humidity
• Atmospheric pressure
• Rainfall

I may combine outdoor measurements with inside the observatory. 

I can mount a Stevenson Screen on the north wall of the observatory to contain sensors for ambient temperature and humidity.  These sensors and transmitter can be powered from the observatory.  Atmospheric pressure can be measured indoors.  That leaves the wind and rainfall measurements. 

Edited June 23, 2020 by Gina

[Chriske]

You could use the encoder disk out of an old computer mouse or completely other approach, Hall sensors..?

[Gina]

Earlier designs have used optical encoder discs and photo detectors.  Hall sensors are less precise as are reed switches.  I'm thinking of going back to optical sensing with Gray coding.

[skybadger]

Hi I am rehashing the guts of my old maplins weather station with an esp8266 for the wireless aspect , only needs 4 pins, 2 are i2c, 2 are edge detect for the wind speed and  rain counter. The i2c provides temp, pressure, humidity, adc and even an Sqm if needed. The Adc is used to read the wind direction resistor encoding. Sadly it needs power but a solar panel might do for that. 

Total cost , about £30 in components.

Edited June 23, 2020 by skybadger
Sp.

[RadekK]

I have just started a new development project for my weather station, to replace old one which served me for last 4 years or so. The retired version  was using:

- Arduino Mini Pro (Atmega 328p) + BLE

- Weather Meters (wind speed, wind direction, rain fall)

- Rain detector (analog humidity sensor)

- BME280 (temperature, humidity, pressure)

- MLX90614 (cloud detector)

- Light detector (optoresistor)

 

Communication based on Bluetooth Low Energy (JSON formatted data sent by weather station every 300s)

Data collected by Raspberry Pi inside, running:

- Mosquitto server for MQTT publishing environmental data to all other devices at home

- InfluxDB (persistent data series)

- Grafana (graphs and gauges)

I'm gonna keep the sensors and replace the core for the newest Arduino Nano 33 BLE or Arduino Nano 33 IoT. Just waiting for delivery 🙃

[Gina]

II thought you might be using all RPi and not Arduino @RadekK being well versed in INDI.  Those Weather Meters are the same as I used many years ago.  They didn't last very well in the storms we get at times.

[Gina]

When it gets cooler and my brain starts working again I shall be sorting out the sensors, in particular the wind direction, though the main problem is where to put the wind sensors without interfering with my astro imaging.

[Gina]

I think I may have a plan for finding where I can put the wind sensors where they won't interfere with astro imaging.  If I take the imaging rig off the mount and replace it with the DSLR set to wide angle I can take a panorama.  There are trees that already block the FoV from the mount such as to the north where there's a shed I could mount a high pole on but not as high as the trees as seen from the mount.

[Gina]

Bit cooler today and my brain has started ticking over!...  The wind vane can have an optical Gray code encoder with 3 bits which I can easily design and 3D print.  The anemometer can be as it already is with 3 tiny magnets on the rotating bit and a Hall switch.  Low wind speeds can be measured by timing the interval between pulses and higher speeds by counting pulses.  This means 4 bits of data can carry the wind data.  This could be transmitted to the base station indoors where all the data would be processed.  Something like an RPi would seem to be overkill - I just need some form of transmission that can handle 4 bits of data at a relatively low speed.  OTOH it could be that the RPi is the simplest solution.

I know relatively little about modern short range comms but I'm sure there must be something that can handle this.  My old Maplins WS use a radio transmitter at (I think) 433MHz and ran the transmitter station from a pair of AA batteries.  I don't need to use such low power as there will be mains available.  Bluetooth comes to mind but I have not had much joy with Bluetooth in the past and I'm not sure it would have enough range and the ability to work through reinforced concrete walls.  I know a bit more about WiFi and I do know that it has the range.

Edited June 26, 2020 by Gina

[Gina]

This looks interesting - How To Wirelessly Transmit Data on Arduino

[Gina]

IZOKEE 2pcs ESP8266 ESP-01S Serial WIFI Wireless Transceiver Module with 1MB Flash Support LWIP AP+STA for Arduino UNO R3 Mega2560 Nano

Edited June 26, 2020 by Gina

[Gina]

On 23/06/2020 at 17:23, skybadger said:

Hi I am rehashing the guts of my old maplins weather station with an esp8266 for the wireless aspect , only needs 4 pins, 2 are i2c, 2 are edge detect for the wind speed and  rain counter. The i2c provides temp, pressure, humidity, adc and even an Sqm if needed. The Adc is used to read the wind direction resistor encoding. Sadly it needs power but a solar panel might do for that. 

Total cost , about £30 in components.

These? :- IZOKEE 2pcs ESP8266 ESP-01S Serial WIFI Wireless Transceiver Module with 1MB Flash Support LWIP AP+STA for Arduino UNO R3 Mega2560 Nano

I would be very interested in how you made your weather station.

[Gina]

Order placed with Amazon - due to arrive tomorrow.

Edited June 26, 2020 by Gina

[Gina]

I have a 5m long aluminium tube 1½" OD that I can use for the wind sensors.

The casing that I already have has warped badly and won't do so I shall have to produce a new one.

[Gina]

The present casing was made with ABS in several parts glued together with acetone (solvent welded) and is bigger than my current 3D printer can accommodate.  A new casing would need to be in parts and bolted together since I no longer use ABS.  For one thing, it warps!  But that's not the only reason.  New casing will be white PLA.  The present shape is not necessarily the best and I'm looking into other options.

[Gina]

Reckoned to be about the best weather station is the Davis Advantage Pro 2 and I can see advantages in the wind sensors in this station.  This format is much more compact than my last version.  There is very little interference from the support bracket.

[Dr_Ju_ju]

Nice & pricey....

I was contemplating getting an Argent Data Systems Wind Rain sensor (https://www.argentdata.com/catalog/product_info.php?products_id=145) as recommended by the raspberry Pi mob https://projects.raspberrypi.org/en/projects/build-your-own-weather-station 

It would take the hassle out of the more difficult sensors and be able to run everything on a Pi

[Gina]

That Argent Data Systems Wind Rain sensor looks exactly like the weather  station I bought from Maplins years ago.  The anemometers broke up in storms.  I had two of them but gave up after the second failed.

The Davis WS (No relation AFAIK) was just as an idea for mounting the wind sensors.