Saturday, 13 October 2012

Woe, Woe and Thrice Woe

So said the soothsayer in "Up Pompeii". Most of this week has been spent battling with my Arduino rainfall gauge project. First I had decided I needed a four line LCD display. Once that arrived it took a while to get it addressed properly so that filled a morning before it was fully working

To be able to store past records so as to display daily, weekly and monthly rainfall meant installing a real time clock in the circuit. I had a couple of part built kits bought over a year ago. I chose one and soldered in the resistors and connector, wired it up and spent ages finding and downloading different test sketches. Why do Arduino programmers call their programs sketches?

None of them worked. The display always showed the same gibberish. That had taken up a whole day with just an hour break while I installed a new outdoor LED floodlight which had arrived. The following day I decided to build the second real time clock. It is the same make but the one thing I noticed was that the back up battery holder was soldered in the opposite way round. Not my mistake as these came part built! Once the extra bits were soldered on and the thing plugged in everything soon sprang in to life.


No doubt having the back up battery reversed will have killed the first one. I did try unsoldering the holder and replacing it the correct way round - no joy there.

The only thing I have noticed is that the clock gains about five seconds a day and there is no way that I know of to adjust its internal oscillator to fix that. I have ordered another, different make, to see if it is a common fault.

After much research I found a way to calibrate the mechanical part of the Rain gauge and it turned out that two tips of the sea-saw buckets equated to one mm of rainfall.

Now on order is an SD card module to store the rainfall data. It should be fun getting that to work (not).


  1. I wouldn't know where to start.
    Hope you get it sorted John.

  2. I suspect it wouldn't be half as much fun if it was completely straightforward John :-)

    Lovely photos of Penny on the previous post and also of the wonderfully camouflaged Hedgehog. All the dogs we have had have shown surprising trepidation toward small creatures such as Hedgehogs, Frogs etc. Even spiders and beetles have been treated warily :-)

    1. Probably not Jan.
      The Hedgehog was well camouflaged against the paving slab.
      I think Penny just wants something to play with and with moth thing her natural curiosity gets the better of her. Morning walks usually take ages as she has to sniff every snail we meet on the footpath.

  3. Certainly no help when something is already in backwards! Our two month dry spell has ended abruptly so lots of rain here to measure as well. Do you save your rain in a rain barrel with spigot?

    1. It was a pity it was so long since I bought those bits otherwise I would have had a few strong words with the supplier.
      I have eight water butts to catch rain water Glo. Most are used to top up the pond in the Summer.


Thank you for visiting. Hope you enjoyed the pictures. Any comment, or correction to any information or identification I get wrong, is most welcome. John

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