Gina

20 minutes ago, tekkydave said:

Why do you need nano as well as the ESP8266? Is it just a lack of I/O pins on the ESP?

Yes.  I thought the ESP8266 was just a WiFi adapter hadn't thought of it as a microprocessor as well.  I will want one digital and 4 analogue inputs or maybe 9 digital inputs depending on how I implement the wind vane sensor.  OTOH that encoder chip only needs 3 data lines (SPI or I2C forget which).

Been looking at using the ESP8266 with Arduino Nano.  I see it needs programming with things like SSID and WPA password first, which can be done from an Arduino.  Then I presume the Nano is connected to the ESP8266 to send data.  Haven't quite worked that part out yet.  I don't know if the ESP8266 has EEPROM to hold the SSID etc. or whether this needs sending on powering up in the field.

I've ordered some more optical reflective sensors and Hall switches to replace the ones I've lost.  Arriving tomorrow.

ARCELI 10 Pcs TCRT5000L Tcrt5000 Reflective Optical Sensor Switch

10pcs A3144E 3144 OH3144E Hall SIP Three-Pin Effect Sensor

Looks interesting but...  Does it need a faster processor than an Arduino or RPi?  What are the ultrasonic sensors - cost and availability?  I could manage the hardware.  If there was a design with readily available sensors and using either Arduino or RPi with sketch I would be interested but I suspect it't not that simple or there would be lots of them about and rotary wind sensors would die the death.

Rummaging through my box of chips and other components I've found the transmissive opto sensors but not the reflective or the Hall switches which I know I have somewhere.

Thanks Dave.  Interesting but a) I don't want to spend that much money and b) prefer to make my own.

I'm now thinking about the angle sensing for the wind vane.

Possibilities :-

1. Magnet and read switches - some magnetic force
2. Magnet and Hall switches
3. Reflective optical sensing with Gray code disc
4. Transmissive optical sensing with Gray coded discs
5. Magnetic encoder chip

Hall switches instead of reeds avoid the magnetic attraction of reed switches providing freer vane movement but experimentation would be needed to see how well this worked and what overlap occurs.  Optical sensing provides analogue output with code needed to clean up and provide Schmitt triggering.  This is no problem with the Arduino.  The Melexis magnetic encoder chip system has proved less accurate than expected and is difficult to set up.  I don't like it!

Option 3. is probably the easiest to implement mechanically but relies on getting a good differential reflectivity from the Gray code disc.  Some experimentation to get the switching levels right would be needed.  Option 4. give better light to dark ratio but is more complicated mechanically.

Whichever system I use seems to need experimentation.

Here are some images from the ASC showing cloud and raindrops on the dome.

Heavy cloud coming in before the rain.

Light rain just started.

Moderate to heavy rain.

Rain stopped and sunshine but still raindrops on dome.

Raindrops gradually drying off.

Raindrops now almost gone.

After several hours of rain I think I can say that the ASC is watertight.  The pressure equalisation and drain pipe goes into a small jar in the observatory containing a couple of 10g colour changing desiccant (silica gel) grains.  These have darkened a bit but still orange and there's no water in the jar.  With the desiccant open to the atmosphere through a small hole in the jar top I expect to see a gradual absorption of moisture from the air.  Air will be going in and out as the air in the ASC dome cools and warms.

My current wind vane design uses magnetic damping with strong magnets and an aluminium disc but with Consensus Averaging this seems unnecessary and indeed may actually be a disadvantage.  I was planning to us Consensus Averaging anyway and have used it before.

Do you have a link, please?

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.

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.

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.

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.

Order placed with Amazon - due to arrive tomorrow.

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.

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

This looks interesting - How To Wirelessly Transmit Data on Arduino

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.

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.

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.

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.

Interesting clouds.

Camera temperature has dropped to 3.3°C now as the clouds roll in.