Sandaysoft

Hi Ole
I was just looking back at your pre sunrise anomaly and I wondered if it could be aircraft landing lights - the rising level suggests something getting closer and the peaks and troughs might be small movements of the aircraft sometimes shining directly at you. Are you near an airport ? I don't think it could be road traffic - you'd expect it to occur earlier as well. The real sunrise showed up very well - that's the area my primitve design failed on and it does need manual level tweaking every couple of weeks.
Where I am I'm always going to lose some early and late time as I have hills rising a few metres above my altitude in the NE to SE and SW to NW quadrants - I can see the sea horizon to the south but that is not exactly useful.
The latest design drawing looks really good - having the PCB inside might provide just a little heat to counteract condensation. Maybe if you had a higher supply voltage and used the heat from a voltage regulator (it wouldn't be much but in an enclosed vessel it might help) and it might provide a more stable circuit voltage as well.
Once again I have to thank you for your enthusiasm and skill - I believed in the idea but my knowledge wasn't enough to take it where it should go.
Regards
Alan

Hi Alan.
It is probably right that I have the best experience in electronics and programming, but your imagination and ability to 'turn every stone' is remarkable - the way you think and try to find solutions is in my opinion outstanding.
To illustrate I am impressed of the fact that you stubled over the MCloed concept from 1800 something and replaced the original light sentive paper with a photoresistor to see if that could be a method to count sunshine hours.
And I am 100 % sure we are on the right track - why nobody else have got the same idea is strange.
It's a little bit like the Lego system - so simple that anybody could do it - but only one did.
No - we don't have an airport close and also road traffic is somewhat distant - my house is in the real country side.
So what caused the initial light pop up is more likely to have been some remote clouds being hit by the sun light even before i was above the horizon.
I think my idea to set up my camera will provide the documentation required to compare the actual optical conditions with the measured results.
The AD converter I purchased have a spare digital output so I can operate the camera by my software as I choose. Fortunately my place is in fairly high altitude (danish standard at least) of 79 meters above sealevel and I do have about 3-4 km free view in the present sunrise direction from my first floor.

I just briefly checked the USB specs and it seems that a load of 500mA should be possible.
The 1-wire circuit has a very low power consumption so i might consider to include a 15 ohm resistor in - it will give a nice continious heat of 1.6 watt.
Best regards
Ole

Hi Alan.
I got my camera in operation now.
When sun is at elevation -6 to 6 (only AM) it takes a picture every 1 min.
Attached is an example - camera looking at SE.
It looks through some oak trees - the leaves will drop off with the next week or two providing a better look through the branches.
So now - waiting for some sunshine (the recorder works perfectly at present - sunshine hours = 0 )
I will order some 1-wire evaluation stuff today and then see how difficult it will be to get it operating.
Best regards

Ole

Hi Ole
I was assuming you were using an external power supply when I suggested the voltage regulator - I think usb cables are limited to 15M but I don't know if that is a data or power limitation.
I saw the sun for an hour or so today after the low cloud lifted so maybe it's heading your way.
Regards
Alan

Hi Alan.
It's correct that USB cable lenght is limited due to data speed, but as I will use 1-wire system, the cable length is not a problem except for voltage drop if I am loading it to much for the heating.
I intend to use my laptop as permanent computer for the recorder and maybe the 5V output capability is less that the 500 mA.
So the internal heating is an open issue so far but I think that some small ventilation holes plus maybe 200-300 mW will be able able to handle a mist problem.
I will anyway design the PCB so a resistor can be mounted for that purpose.
Yes please - ask the clearing to move toward my place - my camera will be ready tomorrow morning.
Best regards
Ole

Hi Ole
Have you noticed the number of views of this thread - it's certainly got a lot of interest now - from little acorns great oaks grow !!!
Regards
Alan

Hi Alan,
2746 is quite a lot - everybody needs some more sunshine
Did you remember to guide the clearance direction yesterday? - it did not help anyway.
Best regards
Ole

Hi Guys,
I definately don,t know about electronics or software but thinking about a sunshine sensor...would it be possible to use a cheap digital camera taking pictures of say, a white card either continuosly (power ?) or intermitantly.....
they have a light sensor in them...
how about a cheap mobile camera phone...connected via cable....
Just thinking out loud here....

Hi Tonester
It would work to an extent but analysing the levels of brightness would be a problem. Storing all the pics would use up a lot of space although once analysed (but how ?) they could be deleted. My original design lacks complete accuracy but is dead cheap and Ole's looks like curing the problems I had with dawn and dusk light levels. Thanks for the thoughts.
Regards
Alan

Is silence bad news about the project?

Fortunately not – Apenwith and I recently decided that all our technical back and forth communications were better suited for direct mailing – not to keep things secret – more to avoid overload of the forum.

So we decided to make a progress report on a regular basis and here the first one:

The system will be based on two visible light sensors – one for the reflected light and on for the ambient light.
The sensor is special and has a logarithmic response – that means that the unit is far more sensitive at very low light levels (around sunrise and sun dawn) than on high light levels (bright summer sunshine at noon).
It’s has virtual a characteristic as the human eye.
One disadvantage is the size of the sensor – it’s only 3 x 2.3 mm and with 4 terminals to solder – a magnifier glass and steady hand is absolutely required

Further we will use a 1-wire system and a 1-wire A/D converter can be mounted in the unit.
At the PC end we are using a USB to 1-wire adapter but we also must have a wall plug type power supply for 12V supply of the fan/heater.
The cabling from sensor to PC end will be standard Cat5 cable.

The required interface software will be written in Visual Basic (VB.NET).

The sensor will be encapsulated in an acrylic tube only 60mm in diameter and height will be close to 120mm.
Apenwith has tested the temperature rise in a closed glass jar at 12°C outside in bright sunshine – the internal temperature quickly rose to 30°C.
So we have a temperature problem and have decided to add a small fan and a 1-wire temperature sensor so the fan operation can be controlled by software.
Further we might expect some mist problems inside – therefore we will add a resistor as heater element – also controlled by the software.

Another subject is the reflector –I think we have been around all possible solutions – electrical bulbs, Christmas baubles of glass, trying to form copper into the right curvature for later chromic plating.
For the next couple of prototypes we will use plastic Christmas baubles with chromic surface - they are fairly easy to cut to the correct dimension and - strangely enough - available in many shops just now.

At the moment I have a camera ready in the window to take pictures of the sun rise to compare the pictures with the measurements – until now in vane as the sun wants to hide itself behind massive clouds.
That’s it for the moment – it may take a while before we have the final prototype on air for testing but we will keep you all updated along the road.

Best regards

Apenwith / OleJul

Thanks for the update.

_________________
Steve
Sanday Weather
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Excellent work people. is good to be kept in touch.

Will you be making a kit of parts available?


Will it include plenty of sunshine?

_________________
Nothing is foolproof, to a sufficiently talented fool . . .

WH1080PC Rochdale UK, 171m

We will off course consider that - the only snack is mounting the components on the PCB - they are EXTREMELY small.
But we will revert on that issue when have proven the full functionallity.
I would guess spring next year is a good estimate - then we have had the sun at higher elevation.
Just before summer - the high season for counting sunshine hours - right now the count is mostly 0 hours per day.
Best regards
Ole

Hi All
Just to let you know the recorder project is alive and well.
Olejul and I have been exchanging ideas and we have got to the stage of building the first prototypes.
The sensor and electronics are now housed in a very small 80mm diameter acrylic tube - my original large device actually caused my mast to bend slightly in our recent gales.
The test device has worked well so we are confident that we have a very realistic way of recording sunshine.
The latest design has proper production in mind so keep watching - by spring 2010 there may be some real units available.
Regards
Alan

Hi All
We have had to change the design slightly to cover the situation of rime ice forming on the detector which would prevent it from working - that problem has now been solved and so the neccessary components have been ordered for the first prototypes to be made.
At the last count Olejul and I have exchanged over 300 emails so I think we might have overloaded the forum. But it does mean we have looked at as many problems and solutions as we can before we start field trials. The end result is something which looks very different from the apenwith mark 1 version but based on the same principal. With the interfacing software - we think you'll like it - keep watching for the next news.
Alan