LoRaWAN Birdhouse

After the birds left and no new birds started breeding I took down the birdhouse to clean/check the condition of all components. Putting a cork floor on top of the scale turned out to be not so good an idea. The birds used their claws in winter time to turn the cork floor into crumbles. I have replaced the cork now with linoleum (hope this will be more durable). And I have added another coat of linseed oil to protect the wooden panels of the birdhouse. This should hopefully prepare the birdhouse for yet another year out in the field :-) .

The nestlings have left the bird house late afternoon on May 19th. This is about a week earlier compared to what I expected (these guys are fast :-) ). I'm curious to see if there will be a second brood this year.

It looks like the eggs have hatched after about 16 days of breeding. On May 4th the weight inside the birdhouse started going up. The female will warm the hatchlings and both female and male will feed the young ones from now on. According to Wikipedia the young birds should be ready to leave the nest in about three weeks time (end of May/beginning of June). And it still amazes me how fast all of this is happening :-) .

After bringing in about 50 grams of nesting material the female now (19th of April) seems to be almost permanently inside the birdhouse. To me this looks like it has laid the eggs and now only leaves the bird house for short intervals to find something to eat. The eggs should hatch in about 2 weeks time. I'm curious to see if the scale can detect the difference once the eggs hatch :-) . 

I just wanted to let everyone know that the birds have started building their nest again. They started bringing in material around March 26th which is about a week later compared to the years before.

A couple of days ago the birdhouse stopped sending data. At first I thought they where doing maintenance on the LoRaWAN gateways because it started on a Friday evening. After a while I noticed that whenever the sun came out the birdhouse tried doing a LoRaWAN join. That told me that there was probably an issue with the battery because the solar panel was still working. Yesterday I took down the birdhouse. The LIR2032 coin cell was still fully charged at 4.0 volts. It looks like the coin cell holder is the problem (mechanical issue?). Maybe it is not designed for the temperature changes out in the field. Just in case I replaced the coin cell and put the birdhouse back up again. It has been working again without incident for the past twelve hours. I will replace the coin cell with the old LiPo pack (JST connector) should this happen again.

The birds started coming back to the new birdhouse on October 12th. There seems to have been a competition for who gets to stay over night (at one point the scale detected two birds inside the birdhouse :-) ). You can also see the battery lose a few milli volts during the night. This is due to the new LIR2032 coin cell that powers the electronics. It only has a capacity of about 40 mAh compared to the 100 mAh LiPo pack used previously. I'm curious to see if the LIR2032 is enough to get the birdhouse through the winter (I can always put in the old battery if needed).

Update: I just passed the birdhouse on my way home. There was a flock of about half a dozen young birds hopping around the birdhouse flying in and out. I'm no bird expert but maybe there was a realtor there trying to auction off the place (these little guys always make me smile :-) ). 

Version 3 of the birdhouse is almost finished. I will do some software testing over the next few weeks until I will replace the current birdhouse in September. There are some nice features in v3 like a scale with the NAU7802 ADC and two load cells (better mechanical stability). The sides, back and top panel are now glued together to provide better moisture protection. And I have replaced the veneer on top of the scale with cork. Cork is very flexible, naturally water proof and provides good temperature insulation for the birds sitting on top of the scale in winter. The only drawback is it smells a little bit of old wine cellar (I hope the birds will not mind ;-) ). I would also like to keep this birdhouse running for more than a year (the previous versions where only out there for about a year each). I will still clean out the birdhouse/do maintenance whenever needed but I'm curious to see how the birdhouse will hold up over a longer period of time. If you are interested in any further details then please check out the Version3 zip file.

Today I took down the birdhouse to clean out the old nest. The great tits and their offspring left on May 14th and have not returned since (please see the image below). From what I can tell the scale and birdhouse held up nicely. I am also starting to understand the drifting weight values once the birds leave the nest. The nest starts acting more like an obstruction in a clogged pipe (it sticks to the walls) once the birds stop hopping around on top. And this year seems to be a less bountiful season for the birds. The nest is smaller compared to last year and  the drop in weight when the offspring left is also less (I'm guessing fewer hatchlings). I'm kind of curious to see if another bird will start building a nest once I put the birdhouse back up again.

I just wanted to let everyone know that the birds have started nesting again. They started bringing in material around the the 19th of March. And 80 grams later the female now seems to be almost permanently inside the birdhouse (please see the image below). For comparison: Last year they also started bringing in material around the 19th of March and the female started nesting on April the 13th. The nest last year also weighed about 80 grams. It amazes me to see how precise the birds are timing all of this (without wearing a watch ;-) ).