All posts by Peter Young

The Garden Computer Evolving

Just over a year ago I wrote about the Raspberry Pi controller that I built in to a bucket to control the water feature in the kids fairy garden.  The bucket has gone and the controller has evolved in to something much bigger and better IMO.

The controller has gone from using 2x I/O pins for a push button and relay to having an expansion board that runs 4x 240v relays, 8x (with space for another 8) low voltage relays, and 12x Digital I/O pins.  All of these I/O are run from 2x MCP23017 i2c IC’s that give me 16x I/O’s while only using 2x I/O pins from the Raspberry Pi (RPi).  A bonus to this is it also brings a level of isolation which protects the RPi against whatever might happen in the environment.

In addition to this there is now a disused PC power supply that provides a solid +5VDC for the RPi and relay boards, +3.3VDC for some of the garden lights, and at the moment the others stay spare.

The Garden PC Enclosure
The Garden PC Enclosure


In this revision I’ve gone to a complete custom built enclosure.  It’s made from MDF and pine.  While these materials aren’t usually used I have all of the tools to work with wood and not metal.  The back of the enclosure and the door is made from MDF and the other components are made from pine including the top, sides, and divider.

The enclosure is broken in to 2 parts with high voltage (240VAC) on the right and low voltage on the left.  The main reason for this is safety.  I want to keep the separation in case of a catastrophic failure that could put 240V out to the low voltage elements in the garden.

Working through the enclosure, on the right the 240VAC enters the enclosure, goes through the circuit breaker to the connector block and breaks out to the PC PSU and HV relay board.

The PC PSU then supplies the RPi, breakout board, and relay supply boards.

On the right, there’s the PC PSU, Raspberry Pi with WiFi via USB, i2c breakout board, low voltage relay board and connector block for inputs.

The Enclosure, mounting blocks.
The Enclosure, mounting blocks.

This is an overview of the area that the computer is mounted.  The Green blocks on the side of the IBC water tank are the mounting blocks for the enclosure for easy mounting and removal.  The conduit on the wall is for network and power.  The white for network & grey for power.  The flexi-conduit is waiting for the enclosure.

The Enclosure Mounted
The Enclosure Mounted

The enclosure mounted on the blocks with everything closed up.  The blocks on the back of the enclosure have holes in them to drop on to the pins that are on the blocks on the IBC tank.  There’s also a small block on the back of the enclosure at the bottom to make sure it sits out at the same level.

The sloping top is to keep water off the enclosure and out of the seam of the door.  The top is held on with magnets that are usually used for cupboard doors.  This allows for easy removal when I need to open the enclosure.  The door hinges from the left and is held closed with the same magnets as the roof.

The last feature I’ve added is a piece of 70mm PVC Pipe at the bottom with a piece of thin MDF through the middle.  This is just a cable conduit to bring the cables in without exposing the inside to the elements.  The top half is used for low voltage and the bottom is used for high voltage.

There’s not much more really.  On the i2c controller board it has a 1-wire temperature probe which I think I killed in the construction of the board.  I want to eventually add more 1-wire temperature probes to detect inside and outside temperature in case I need to add a fan.  I’ve even thought about putting one in the water feature to keep water running on hot days to keep the algi down.

With any luck I should be able to add the fountain, sprinklers, and some lights to the controller soon.  Then I’ll be working on trying to set up OpenHAB to be able to control this and other items I have networked!


RGB LED Project Idea

I recently purchased a number of WS2812B RGB LED’s from Aliexpress with the intention of doing some fun stuff with them outside.  I failed to notice that they aren’t waterproof and would fail rather quickly.

Inspiration came to me when lying on the couch on the weekend while trying not to zone out too much with the fatigue.  |f I get some thin wire from Jaycar then I could setup a stack of them in the Lego Eiffle tower.  With an Arduino and ethernet shield I could then control it from my phone.  Seems crazy enough so I’ll give it a try.  I’ll post more when it’s done.


After many years of not doing anything with ASCII art I decided to update the issue files on some of the Linux server’s I have so that it’s quicker to recognise them when flicking through VM’s.  When doing so I came across this site that does it all for you which is great as I haven’t done this in years.

Now I have a bunch of pretty issue screens!  It’s sometimes the simple things that work well!

The Raspberry Pi Controlled Water Feature

Down the side of our house we have a small Fairy Garden for the kids to play in.  It’s slowly growing in with the plants and now we’ve installed a water feature.  The 3 tier water feature was found on the side of the road as it has some cracks in it.  After sealing it up with a bit of silicone and duct tape it’s all nicely sealed and water tight.

I built up the wall and back filled the garden bed with the white rock and lined it with clay from under the rocks.  The 2 higher tiers are mounted with liquid nails on top of spare bricks.

To control the whole thing I initially installed a 24hr timer that would switch on for 2 hours a day between when the kids got home from school and dinner but the kids wanted to use it on the weekend.

In comes the scavenging and re-purposing to get something sorted!

At work I found an Internet Power Board that was being thrown out as it had a faulty controller.  A quick inspection found that the High Voltage switching end was easily controlled by a GPIO line from a micro-controller or microcomputer.  I had recently ordered a Raspberry Pi for another project I’d been working on but it hadn’t worked out leaving it nicely for the controller.  I tested hooking up the HV board to GPIO pins without any modification and it worked a treat.  With this being the case I went ahead and mounted it all in a bucket I picked up from Bunnings that has sealed it all from the weather.

Low Voltage End of the Controller.
Low Voltage End of the Controller.

Here you can see the Raspberry Pi in the pink box.  This is the box that it was shipped in and holds it quite nicely.  I added a ribbon cable extend the GPIO ports to the outside so the board wasn’t exposed.  The thick wire coming in from the grommet and conduit is from the push button that allows the kids to turn on the water feature for 10mins.  The power comes from the HV side via a cut off USB cable.  The small grey ribbon cable heads to the HV board to switch the relays.

High Voltage Side of the controller
High Voltage Side of the controller

This is the High Voltage (HV) side of the controller.  The board is unmodified from the device I pulled it from which came with a 5v+DC power supply as well that is mounted behind the HV board.  The cables heading out of the grommet are the 240vAC in and the 240vAC out to the pump.  There are also 3x spare IEC outlets that are begging for some extra hardware to be added 🙂

All of the controller covered and enclosed
All of the controller covered and enclosed

When I had finished mounting everything I went to down with some spray paint, masking tape, and permanent marker.  It isn’t very neat but it gets the message across!

The water feature from the front
The water feature from the front

Here’s the finished water feature from the kids perspective.  All of the business end is behind the yellow fence and keeps it out of the way of inquisitive fingers.  The button to turn it all on is at the back of the left side.  Eventually the plants will grow up nicely to help cover the gaps in the rocks.

To finish it all off I will end up covering up more of the pebbles with fake turf so the kids can walk around without hurting their feet on the pebbles.

In the future I may take advantage of the spare GPIO ports on the Raspberry Pi to include sensors for switching on lights etc but at this stage I’ll leave it as is and let the kids enjoy being able to switch it on!



Welcome to my website.  I am hoping to use this as a page for my ramblings and project ideas that I seem to have a few of (as crack-pot as some are!).

Feel free to comment and let me know what you think.  All of the ideas are posted here under good faith.  They are to be kept Open Source and all rights to manufacture any of these products more than one off for personal use must gain my authorisation before proceeding.

I hope you find this fun and informative.