Wordless Wednesday

18th January 2007

Home Brew Weather Station (Part 1)

I've been working on my home brew weather station based around an Arduino Uno R3. It will measure and display outside temperature in Celsius, percentage relative humidity and rainfall in millimetres.

Temperature and humidity are detected with a DHT22 module:


Rainfall will be measured with a tipping bucket:


Inside the box is the tipping bucket so designed that water entering fills the high side of the bucket. That causes the seasaw to flip emptying that side and presenting the other side to collect more water:


The number of flips is detected with a magnet and a reed switch. This bucket had failed, as they often do after a lot of use. It would appear the reed switch, which consists of two short metal bars which bend and close the contact when a magnet is close, becomes weak and the contact is not made or the contacts become corroded somehow and again stop the contact being made.

This is the original reed switch in place with a replacement next to it:


Originally the reed switch was placed so it made contact briefly as the magnet passed it but that was no use for what I wanted so I offset the new one so it closes when the bucket is in one position and opens when the seasaw tips over:


Here you can see the positions of the reed switch and the magnet when closed:


and when open:


Finally the display which uses two 8 digit 7 segment LED displays:


Top left Temperature in Celsius, top right relative percentage humidity.
Bottom row rainfall in millimetres. The programming for the rainfall got a little complicated as the rain gauge apparently makes 3 tips for each mm of rainfall but I got there in the end.

Next job is to box the workings and wire it all up.

Monday Mystery - Guess What

OK. Last week's mystery photo brought out some interesting guesses. It could well have been the top of a thermos flask but in fact Adrian hit the nail on the head ... it was a close view of a light / lamp / bulb socket. Wilma also mentioned light socket but wondered where the contacts were. I kept them out of view! It is  heatproof ceramic socket for Edison screw bulbs. Anyway they both deserve my congratulations and the virtual Midmarsh Gold Star.

   

I did have another close shot for this week but changed my mind at the last minute. As I was putting my soldering iron away in the shed I noticed a cloud formation I have seen many times in other peoples' photos but have never seen myself, until today. Your task, if you wish to take it, is  to identify the name of this formation of clouds (yes I do already know the answer - I hope).

Guess What:


Please leave any guesses in the comments.
They will be revealed, along with the answer, next Monday.
No prizes except maybe a virtual Midmarsh Gold or Silver Star.

According to Reevoo some Birds' Names are Rude

Today I received an email from Reevoo requesting a review of the bird seed I buy from CJ Wildlife. As I think the seed is excellent I was prepared to spend a few minutes extolling its virtues. That was until I listed some of the birds it attracted which included 'Blue Tit'. Immediately a red box with red lettering came up accusing me of using rude words and requesting any rude words be removed.



What a simplistic, stupid checking system they must have which seems unable to check in context. It gives me the impression the site was designed on the cheap by inexperienced programmers.

I could have found the situation funny and altered the list of birds but then why should I? A site like that has to cater for reviews over a very wide range of subjects and businesses. Apparently they just haven't thought things through or cannot be bothered to take the effort to make their site user friendly. It is definitely on my short list of sites I will never use again and have emailed them and CJ Wildlife to make both aware of my feelings. It will be interesting to see what, if any, follow up I receive.

Here is a photo of a rude bird (according to Reevoo):

Friday at the Flicks - Greenfinch

While I was faffing about with Arduino coding for my weather station I nearly forgot about a video. Anyway I just made it with this video capture of a Greenfinch which visited the bird table earlier in the week:




Much as I like to see them, especially since their numbers plummeted, I am always a bit worried in case they once again bring the finch disease. This one appeared to be good and healthy.

Wordless Wednesday

Alford Windmill, Lincolnshire

Monday Mystery - Guess What

Congratulations and the virtual Midmarsh Gold Star to Adrian and Ragged Robin who were both spot on with their guesses. A few years ago there was the branch of a potted bush sticking out over the end of the pond. One day I saw a Kingfisher perched there but it spotted me before I could photograph it. The bits of branch I put up are there in the hopes that one day a Kingfisher may return and give me another photo opportunity:

 


Back to a close view of an object for this week's mystery photo.
Guess What:


Please leave any guesses in the comments.
They will be revealed, along with the answer, next Monday
No prizes, just for fun and maybe a virtual Midmarsh Gold or Silver Star.