Sunday, 27 January 2019

LED backlights for birdbox illumination

All my birdboxes have Infrared (IR) and white light illumination, using 5mm LEDs.  The IR ones that I use give nice diffuse lighting, however the  white light ones tend to give a 'spotlight' effect.  I spotted these LED backlights recently from Pimoroni and once installed, they give a nice diffuse 'daylight' effect:

Underside of roof camera insert.  The circular black thing is an IR-cut module.

This year's new small bird boxes are equipped with two each.  They are wired in parallel to 5V with a 50 ohm resistor for each one, as well as another 50/100/200 ohm resistors between the ground and the uln2003 i/c transistor that is used to switch them for low/med/and blinding light levels.  Default is medium.

This picture shows the underside of the roof 'insert' for this small birdbox.  To the top and bottom are 5 IR LEDs in total.  These are wired in parallel, the only resistors are between the ground and the uln2003 (same arrangement as above there).  100 ohm seems the sweet spot.

The IR LED setting is still a bit spotty for my liking.. but I haven't found an IR led panel.... 
Last year's version of this used 4 IR LEDs, on in each corner, leaving a dim bit in the middle... which is exactly where all the action is... I fixed this this time by adding a fifth LED that points a the middle specifically.  The camera is rotated by 90 degrees to include the entrance hole in the image as well.  A 3mm green led indicator is added via one of the GPIOs (+10k ohm resistor) so that if I cant connect to it, it's obvious from the ground that there is/isn't power.

The diffuse white LED is an improvement on a previous version of this that uses 5mm white LEDs:

Nasty spotlighting in a previous version of the 2019 build, will be re-made with LED panel...

This is the business side of things:

Apart form the modifications described above, it's exactly the same setup as last season's box: Raspberry pi ZeroW (wifi), 8 MPixel v2 IR camera, IR-cut module. 5mm IR LEDs and White led panel (updated).  Illumination has high, medium and low (mood lighting) options.  Power is via 12v to 5v step-down. 

Video capture uses pikrellcam.  Video / image captures are stored locally, and can be archived off to a separate PC via wifi.  Local video storage overwrites if space drops under 20%.  This version uses the 'Lite' version of Raspian, so there is 13Gb available on the 16Gb micro SD card.  Based on last year's nesting activity that is good for approx 1 day of before a review is needed.  The prototyping board sitting on top of the Raspberry pi zero W is wired as described in this post (minus the rat-nest of wires for the LEDs...)

I wanted to add a microphone this year, but had real trouble getting a USB microphone adaptor working without noise interference.  The semicircular thing poking out the micro USB socket is a microphone, but its a fairly poor one.  I will probably not turn it on in practice... ironically a usb webcam I had spare gave flawless audio, but there was no way to fit it in and it seemed a bit silly to use an additional webcam as a microphone anyway...

Saturday, 11 August 2018

Tawny Owl NestBox Wifi Hotspot - setup the correct way...

Earlier this year I setup a Raspberry Pi v2 minicomputer as a wifi access point to use it as a 'Wifi Hub' so that two nestbox cams based on its smaller WiFi-only sibling, Rasp Pi Zero W could connect to my local network, described in 'Wireless access point bird box', this sort of worked but had issues.

This version is for the 2019 Tawny Owl nest box:

2019 Tawny Owl nest box, work in progress
I'm trying the new Pi B+ to use as a remote, wifi access hub that will live in the box and allow other nearby/camera-enabled ZeroW's to connect via wifi. The PiB+ wifi hub will double up to stream a webcam & attached Raspi Camera module too.

My first attempt at this (Pi v2 no cameras + 2x Pi zero Ws, 1 camera module each) is all powered by one Power over ethernet (PoE connection).  The Pi B+ is described as having faster wired network (ethernet) connection, so I theorised that it could better act a video streaming hub for several Pi zero Ws.

Why not buy a commercial wifi access point you ask?
  • This build costs the price of a raspberry pi 3B+, case, SD card & power adapter - so not far off buying a commercial Wifi access point.
  • The access point will 'double up' to host/stream video for its own webcam and a RaspPi camera module - show me a commercial wifi access point that can do that...
  • Its more fun than just buying a commercial one.  Really.
  • You can re-task it as an arcade table (I made this one), Media server, Kodi box, weather station, etc, etc

My first attempt at this worked.  Mostly.  The problem was that the method that I used included adding a DHCP server.  Every network has a DHCP server on it somewhere. Domestic networks typically have one running on their Internet service provider-provided modem/router (BT/Virgin/Sky etc).  A DHCP server ' hands out' network addresses (called IP addresses) to local devices connected to the network (e.g. PC/tablet/smart TV).  Think of it as creating a 'map' so that network traffic can be routed between devices.

The presence of a second DHPC server on my Raspberry Pi v2  caused intermittent problems as there were two operating on my network, beavering away and assigning different IP addresses to the same devices.  Annoyingly the device they fought over the most was the TV, so understandably that was not well received.

So, plan B (+)

An upfront disclaimer, most of this method is not mine, and is reproduced from parts of this 'how to' , and credit to its author jamesh (Paspberry pi Foundation).  I re-jigged it a bit to make it flow better and added in my own comments.

The first bit deals with making an a standalone wifi network... which is what I did first without reading it properly....  You actually want to follow the second part of the section that deals with setting it up as an access point to an existing network. 

One common use of the Raspberry Pi is as an access point is to provide wireless connections to a wired Ethernet connection, so that anyone logged into the access point can access the internet, providing of course that the wired Ethernet on the Pi can connect to the internet via some sort of router.
To do this, a 'bridge' needs to put in place between the wireless device and the Ethernet device on the access point Raspberry Pi. This bridge will pass all traffic between the two interfaces.

Use the following to update your Raspbian installation:
sudo apt-get update
sudo apt-get upgrade

Install the following packages to enable the access point setup and bridging:
sudo apt-get install hostapd bridge-utils

Comment: reboot at this point, or the 'add bridge' bit below wont work.
Since the configuration files are not ready yet, turn the new software off as follows:
sudo systemctl stop hostapd

Bridging creates a higher-level construct over the two ports being bridged. It is the bridge that is the network device, so we need to stop the eth0 and wlan0 ports being allocated IP addresses by the DHCP client on the Raspberry Pi.
edit: May want to save a version of this text on the pi's desktop before doing the following as you'll lose the internet temporarily
sudo nano /etc/dhcpcd.conf

Add denyinterfaces wlan0 and denyinterfaces eth0 to the end of the file (but above any other added interface lines) and save the file.

Add a new bridge, which in this case is called br0.
sudo brctl addbr br0

Connect the network ports. In this case, connect eth0 to the bridge br0.
sudo brctl addif br0 eth0

Now the interfaces file needs to be edited to adjust the various devices to work with bridging.
sudo nano /etc/network/interfaces make the following edits.

Add the bridging information at the end of the file.
# Bridge setup
auto br0
iface br0 inet manual
bridge_ports eth0 wlan0

edit the hostapd configuration file, located at /etc/hostapd/hostapd.conf, to add the various parameters for your wireless network (SSID) and password (wpa_passphrase).
sudo nano /etc/hostapd/hostapd.conf


We now need to tell the system where to find this configuration file.
sudo nano /etc/default/hostapd

Find the line with #DAEMON_CONF, and replace it with this:

Now reboot the Raspberry Pi.
There should now be a functioning bridge between the wireless LAN and the Ethernet connection on the Raspberry Pi, and any device associated with the Raspberry Pi access point will act as if it is connected to the access point's wired Ethernet.

The ifconfig command will show the bridge, which will have been allocated an IP address via the wired Ethernet's DHCP server. 
A few more observations...

Raspberry Pi v2 has no built in wifi so I added a usb wifi dongle to the original version I did.  
The Pi 3B+ has built in Wifi (both have ethernet), so there's no need to add wifi dongle.  My Pi v2 version works fine over Power over Ethernet (PoE).  The version B+ most definitely does NOT, so 2019 Owl Box will need a better power supply (and better power cable) to the top of its tree than the optimistically planned PoE only solution.

Sunday, 29 July 2018

Whats wrong with our Tawny Owl Nest Box?

Our Tawny Owl nest box was 'temporarily' retired last year because I hadn't designed it properly it was difficult to clean out the squirrel detritus.

This pic is taken while dangling precariously from a ladder approx 30ft up a pine tree. 
The box is full of sticks collected by squirrels, so no owls are going to use this... Ideally I would have designed it so that I wouldn't have to climb up another couple of extra feet to open the lid to clear it out, but I built it basically as a massive 'small bird box', and didn't scale up my lateral thinking facilities alongside.

Feeling creative I drew this up detailing all its other problems...

Its been on a 'to do' list for a while, and I was inspired by Kate Macrae's recent Tawny Owl Box re-build described here to get around to doing it.

To make matters worse, in an attempt to adapt it a little while ago, I took the side off (side facing in the diag above) to make a 'cleaning out hatch', and promptly misplaced the whole side.  It is now what could only be described as 'drafty'.  The front ledge fell off too...

Enter Tawny Owl Box v2
Its replacement aims to address all the issues described above, and add some more cameras with the requisite illumination (IR and visible light).  Probably.  Eventually.

Saturday, 7 July 2018

BirdBox infra-red camera IR filter upgrade

Now that the bird nesting season is over, it's upgrade time! The infrared (IR) cameras in this year's boxes are getting IR filters...

and some to spare...

This year's two new bird boxes have an infrared (IR) camera with visible and IR LEDs (Robin box Birch log tit box).  There is 'night mode' with IR light  that the birds cant see, and day mode with optional visible light illumination. All non IR-light sensitive cameras have an IR filter built into the camera, whereas IR-sensitive cameras don't.

Without an IR filter, IR camera images have a pinkish cast to them in visible light, giving a permanent 'Hipstamatic' look:

Un-filtered IR camera pink colour is obvious here

An IR filter (called an IR-cut) converts an IR-sensitive camera into a conventional one that can't see IR light.  This gizmo has a bit of glass in it that blocks IR light, and can move backwards and forwards over the camera lens by changing the voltage polarity applied across it.

These bird boxes use the 8MP Raspberry Pi IR camera board.  This has a similar shape and design to those found found in many commercial CCTV cameras, so IR filters designed for CCTV camera modules can be fitted to them.  Sort of...

My first attempt to do this was the top-down camera in last years's double camera bird box.  Unfortunately, I sourced an IR-cut that had an ?M12 lens mount on it, basically a dirty great chunk of plastic poking out the font that needed to be cut off before I could use it = fiddly.  You can see my v1 test for this here from a separate project:

I wanted something easy to add to this year's boxes, and found an IR cut filter without a lens mount which fits nicely over the existing screw holes in the Raspberry Pi camera module (22mm separation).

This come from AliExpress (China, so take a couple of weeks to get to the UK), and costs $3.50 so wont break the bank.  It comes with a separate lens mount holder which I haven't used.  There's the option of 20mm or 22mm screw hole separation at order - you need the 22mm one as to fit the Raspberry Pi camera board.

This shows the underside of the camera unit that is slotted in to the top of the birdbox, pre and post IR-cut upgrade. The ir-cut is attached over the camera by M2 nylon screws and nuts, and the screws just go through the 4mm ply and pass through the camera board.

IR-cut sitting flush against the 'underside' of the bird box camera insert

I had previously designed this year's Raspberry pi zero W add-on board with an IR-cut in mind.  The voltage polarity reversal to switch the IR-cut is done with a L293DNE (£2.70).  I did  a more detailed writeup of this here which also has some example code.  The design for the wiring of this my customised add-on board is detailed here.

No birds in this, but you get the idea what switching the IR-cut in natural daylight does... there are alternatives to this, eg here which has integrated IR LED, camera and IR cut - does not have stellar reviews on amazon though.

Sunday, 1 July 2018

How to make a Solitary Bee Box

We noticed a solitary bee using a gap between some tongue and groove wood cladding on the rabbit shed, which led to this bee house build...

The aim of most solitary bee house designs should be to...
  • Provide a safe place for solitary bees to nest.
  • Provide somewhere safe for new adults to emerge in the Spring
  • Allow easy access to cocoons for collection and cleaning at the end of the season.
This is our v1.0 bee house attempt:

Solitary bee boxes come in many different varieties, but are variations on a long narrow opening into which nesting chambers are constructed.  Examples include:
  1. Bamboo canes: Variable sizes kept in a container of some kind.  Can source yourself or get online.  Disadvantages are you cant collect cocoons so allows disease, predator and parasite build up over time.
  2. Reeds: As above, but may be able to split to get the cocoons out.  
  3. Drilled blocks/logs.  Same issues as bamboo
  4. Cardboard tubes +/- paper liners: Looks a bit of a fiddle, but might try this one in the Spring
  5. Stackable trays with pre-cut channels.  Channels cut into flat pieces of wood that are stacked, e.g., wildlifeworld.  This option came out on top, with cardboard tubes a close second.

Female bees collect pollen.  Female bee deposits the pollen in an appropriately sized hole.  She then lays an egg and closes up a chamber containing egg+pollen with a mud wall .  She repeats the process until the hole is full with multiple chambers.  In the Summer the eggs develop into larvae, feed on the pollen stores and develop into a cocoon.  In the following Spring the new bee emerges from the cocoon.  Males emerge first so that they're available to inseminate the females, who then go onto to perpetuate the life-cycle.

This v1.0 design is based on the stackable tray type.
  • Longer holes produce more females.  Females do more pollinating than the males (who hang about at the beginning of the season to inseminate the females then die).  We made 7.5 inch long trays, with the channels cut right to the end.  Some websites had examples up to 11 1/2 inches long, but I had limited timber stocks to work with!
  • Channels are 5/16 inch deep and 3/8 inch wide, which is the recommended size for mason bees.  I used this 1/4" square-end router bit.  I wanted a round ended (or 'bull nose') bit but couldn't find one the right size that didn't cost the earth.
  • Trays were cut from one piece of 18x199x2400mm pine (mixing imperial and metric, sorry), so I got 12 trays out of one piece.
  • Each tray has 8 channels giving 96 channels in total
  • Rather than routing these individually which would be a pain, I just routed the wood into one very long tray and then cut that into sections.
  • As the channels go through to the back, there's a piece of cardboard folded over the back end (as in this video).
  • The front of the block is unevenly scorched, as this apparently that helps them find the correct hole.  Other variations of this include marking the front, or using differing colour trays.
Stacked tray block before and after scorching
  • The stack is bound together by a tie down strap with metal cam buckle (I had to google the proper name for that) picked up from the local DIY shop, but can be sourced elsewhere.
  • There's an 'emergence drawer' at the base for any cocoons we collect this year (prob a bit late, may get a batch in for next Spring).  This gives a safe place for adults to emerge.  The holes in the front allow the newly emerged bees out (drawer would be closed...).
Safe place for new adults to emerge from cocoons in  the Spring

  • A South-Facing position is recommended, we settled for S-SE 

The effect of scorching is more obvious in this pic

The box housing the bee block is made from 'stuff lying about', but mostly is 6mm ply and finished with a coat of linseed oil.  No oils / preservatives are applied to the blocks themselves.

Most of the solitary bee info stuff that I could find in the web dealt with Mason bees, but there are many others which presumably have their own nesting preferences.

Some links that I found useful (watch them build, had a spot on Springwatch 2018) no tech in this one, but I like the idea of this bee counter discussion thread, which aims to count honey bees activity around a nest entrance hole using a raspberry pi camera... Could theoretically apply the same approach with a down-facing camera on this box...

Wednesday, 6 June 2018

2018 Birch log blue tits: The odds were stacked...

Our first bluetits hatched on the day of the Royal Wedding, so the first pair were predictably named Harry and Megan.  We were lucky enough to catch one at the point of hatching, the sequence below is speeded up a bit:

Others  followed soon enough...
day 1-2 , all looking good....
We had noticed previously, that the female bluetit had a tick next to her right eye, but didn't think much of it, since we all have to contend with the nasty critters.

Tick below right eye.  Really.
The tick disappeared within a few days, but she proceeded to have a fairly dramatic reaction with a lot of swelling around the eye which was also accompanied with feather loss; she was practically bald on the right side of her head.

Adding to her woes, the male appeared to have left the scene, so we had a one-eyed single mother with 5 yet-to hatch + 3 chicks to look after... not looking so good...

She was managing for a couple of days, but fell into a pattern where eggs would hatch and within a few days the new chicks died.  Megan and Harry were hanging in there though.

Food was varied, we saw a lot of huuuuge caterpillars / grubs that are not going anywhere (except maybe by tunnelling their way out).

Some sibling rivalry in the next clip, with Harry and Megan are fighting over a caterpillar...
You can see ?tick-related feather loss on the adult's head quite well here too.

When the adult feeds, she takes turns in selecting which chick gets fed.  One chick really wants to hang onto the food and gets flung about a bit.  An avian version of the magnetic fishing game.

As this is our first (semi) successful nest for several years, I'm not sure if the next clip showing a chick on top of its mother is normal behaviour, but she sometimes doesn't get the idea of sitting on the chicks to keep them warm...

The lack of a second adult, together with her erratic feeding lead to the inevitable deaths, while Harry and Megan soldiered on.  This clip shows her removing one of the smaller chicks that didn't make it.

Another observation from this nest was that there seemed to be quite a range of hatching intervals. Some chicks were hatching up to a week after the 'Royal pair'.  If this was an owl nest I could understand the concept of a spare/(?heir) or one saved for a lunch snack.  One theory I suppose could be that staggered hatching times maximises the chance of at least some surviving a short period of limited food.

Three big, one small. fast forward to day 6.  She removed 3 more dead chicks between 8:00 and 8:30 am, leaving two unhatched eggs and our original pair, Harry and Megan.

By this point, her right eye is looking seriously, well wrong...  I'm fairly sure this is tick-induced, however the tick itself appears to have gone.

Unsuccessful attempts at feeding include very large grubs and sunflower seeds (presumably from our feeder...)

In the end the female bird failed to overnight in the box and the Megan and Harry didnt make it through the Friday night.  She was back in the morning, even attempting to feed the dead chicks..

This clip is a great example of the 'cycle of life', so even if this nest has failed it still feeds the maggots, who in turn into flies to feed something else....

After clearing the last chick out (?Harry/?Megan), she did attempt to incubate for day or so, but eventually left.  We haven't seen her since.  We're hoping that she can recover from her tick injury without having to feed a brood.

So currently our BirchBox next box has this in it.  Black ants have finished off the cleaning up that the wrigglies missed:

Take two...

  • Days 1-14 of this nest are described here

Friday, 11 May 2018

2018 Birch log blue tits, Nest building, egg laying and incubation days 1-13

13 days in from the start of blue tit nest building, we're up to 8 eggs.  Three eggs were laid on day 6 (ouch) then approximately one egg per day.  She started incubating in the last couple of days.

Video and images captured using PikrellCam on a RaspberryPi Zero W.  This box's build is described here.

This is a slide show of nest building and egg laying using a mixture of IR and visible light.  The pinkish cast on the visible light is due to the lack on an IR-cut filter on the camera... I'll add one for next year.

Having looked at other blue tits nests, it seems that green tennis ball fluff is quite the 'in thing'.  In this one is also rabbit hair, sheep wool, straw, moss and feathers from my neighbour's chickens...

1st eggs laid on day 6

Day 9, egg in the sunshine, infra-red illuminated

Day 13, 8 eggs, incubating most of the time now

Some video clips

Female being fed on the nest while laying (not incubating in earnest yet)

This one with the lights on

All seems to be going well, other what is probably a tick above her right eye.  Goes with the territory in these parts...

Part 2 of this series is here, unfortunately it doesn't end well.... and the tick does not help...