« Older Entries Subscribe to Latest Posts

26 Jan 2015

Adventures in RPi and soldering

Posted by jenwren. 1 Comment

Apart from home improvements, I’ve also been tinkering with computers and electronics, especially over the Summer break.

It started with buying a Raspberry Pi last September. A Raspberry Pi (RPi) is a small computer designed to be tinkered with. Rather than explain it, go read about it here. My aim was to play around with some time lapse photography and to learn to code in Python.

First up I played around with time lapse with a camera connected to the Pi with a ribbon cable. I wanted to capture the lunar eclipse in October and did a lot of playing around with the exposure and shutter speed at night.

timelapsepi

In the picture above the RPi (in a plastic case with the red power LED lit) is sitting on top of the rechargeable battery pack that’s powering everything and the white ribbon cable runs up from the computer to the camera on the tripod. The camera itself is tiny and you can’t really see it there. I was running it “headless” without a monitor, keyboard and mouse – instead I can log into it over my home network from my Mac and run commands from there. To preview images, I used Berrycam on my iPhone that also connected over the network (there is a wireless dongle on the RPi).

timelapsepi1

With a bit of fiddling with the exposure and white balance (depending on cloud and a few other factors) I was getting good images, but I didn’t capture the eclipse because the moon was hidden behind cloud. I will try again some other time. For the image above I had a long exposure – a plane has left a trail over on the right near the moon.

The RPi runs on Linux, which was new to me, so to learn more about Linux and the RPi I went and did a course over two Sundays in late November/early December. The course was very helpful in getting me started. Suddenly having one RPi wasn’t enough – I bought a second to use as a media centre.

mediacentrepi

Setting up a media centre was so easy – there are many tutorials, but I used this Lifehacker one, an Adafruit tutorial to set up the remote control (you can see the infrared receiver above the RPi bottom right in the picture above) and this one on setting up Aussie catchup TV. It’s a bit clunky and a few of the catchup TV services don’t work, but those that do are great – it runs smoother than Airplay from my iPad to the Apple TV has been doing lately (I’m still running an iPad2, which is a tad old now!). I can also run video files off a USB stick connected to the RPi and I could set it up as a PVR but haven’t bothered for now. It cost about $100 all together, sourcing most bits via Tronixlabs.

My next Rpi project was going to require some soldering and I sucked at soldering, so it was time to do something about that. I participated in a Kickstarter by Soldering Sunday and three “Chip” pixel pals arrived just before Christmas for me to solder together.

chip1

This one with blue eyes was the first one I put together – I scorched the board just above the first resistor on the left, but otherwise it went well. By the end of the third I was getting better, though the red eyed one has a dodgy connection somewhere because I have trouble getting one of the eyes to work sometimes.

chip2

The pixel pals are designed so they can be plugged directly into an Arduino, which is a different electronics platform, also meant for electronics and programming. But just so I could play with some Python coding, I’ve connected up a Chip to the GPIO (general purpose input output) pins of the RPi (via a cobbler and breadboard in the image below) and made the LED eyes flash just for fun.

chip3

So now that I could solder better than before and with a bit of coding knowledge, I moved on to a more ambitious project – a couple of waterproof temperature probes connected to a LCD display and able to log data to a file. The purpose of this was to monitor the temperature of solar dye baths (Yup, there’s some fibre crafts hidden in here!). I did attempt some solar dyeing a few years ago (it seems I did not blog it) but the dye never took too well and my guess was that the dye baths weren’t getting hot enough and I didn’t have a thermometer. Making a RPi-powered LCD and temperature sensor rig is complete overkill – I could just buy a thermometer – but that’s no fun!

I should have taken more photos while I was building this – first I connected up all the parts with the cobbler and breadboard to check it all worked, then I worked on the code to get the temperature readings to be displayed on the LCD. Once I was sure it worked, I assembled it in a plastic box with a clear lid (so that it is relatively waterproof), soldered the wires and insulated them with heat shrink and, as I only needed seven of the first ten GPIO pins, plugged it all into the RPI using a 10-pin IDC cable.

temppi1

Here’s a photo of it doing not very much because I forgot to photograph it while I had an experiment running on the terrace to see how hot a dye bath would get in the Sun.

temppi2

And this is the LCD screen output. The time and date refreshes along with the temperature data which tells me the program hasn’t crashed. I can add more sensors if I want, but two sensors gives me the ability to make some simultaneous comparisons. I set this up with two different sized dye baths on a very hot day and collected data over about eight hours using a second Python program that wrote the data to a file that I could later import into Excel…

temppi3

And the dye baths didn’t quite make it to 50 degrees – not hot enough to fix the dye. Bummer.

18 Jan 2015

Home Improvements

Posted by jenwren. 2 Comments

Last time I mentioned the myriad of home improvements in progress in my new home (I played yarn chicken and lost) my storage cage was stuck at half-built, no one could make me a gate for a reasonable price and I had six moving boxes still to be unpacked.

Firstly, I built myself a gate and, with help from my brother Tim, the gate was installed in late December 2013, complete with lock (no more opportunistic attempts at break ins or prowlers on the terrace).

gate

After more drama than I care to revisit, I finally had the second panel of the storage cage installed in mid-February.

storagecage4

And I promptly retrieved the remaining belongings stored in my parent’s garage and filled the cage. It’s not quite so messy as in the photo below – after amalgamating my belongings I sorted through them and placed some of it on Gumtree and sold stuff, and some stuff went in kerbside garbage collections.

storagecage5

So with the freezer shifted to the storage cage, some other rearrangements had to happen – for a time the microwave oven was a problem, taking up precious bench space and needing an extension cord across the kitchen. I was just about ready to drill holes in the back of the cupboard over the fridge to make access to the spare power outlet above the range hood, until I accidentally flooded the dishwasher and by happy accident discovered there was a double power outlet behind the cutlery drawers. One power outlet was for the dishwasher, the other was for the stove ignition system that is broken. I’m happy enough using a gas match to light the stove, so the microwave went into the slot (perfect fit!) and the cutlery drawer contents went to the sideboard – they will get a new set of drawers back in the kitchen down the track…

shelvesbefore

The next wave of change was to reconfigure the book shelving into a taller, more compact arrangement. This is an Ikea system (Ivar) that I’ve gradually expanded over many years to replace old bookcases that didn’t survive previous house moves too well. By replacing the side units for taller ones, and adding about another 10 shelves (all of which had to be sanded, stained with Japan black and sealed with Cabothane) the whole lot now goes up to the ceiling and takes up less floor space.

shelvesafter

It took weeks to sand/stain/seal and two solid days in April to construct and bolt to the wall. But the improvements to the layout of the open plan living/dining/kitchen were huge – mostly because I moved the sideboard across the room and moved the dining table against the wall so that I stopped colliding with furniture that was too close together! The other benefit was that I was finally able to hang pictures on the walls – knowing which bits of wall were going to stay visible. The place finally started looking less temporary.

And then not a lot happened, because I was consumed for months of 2014 on a teaching appraisal that sucked every spare moment of my time. With that successfully completed (hurrah!), in October I ordered the parts to undertake the next major improvement – the pantry. At the start of my summer break in December, I whittled down the six remaining moving boxes (that became five at some earlier stage) to two.

twoboxes

That’s yarn (of course!) in the box on top, and the three other smaller boxes were the pantry parts. I hope to empty those last two boxes soon – then I might finally do something about decorating my bedroom. It is the last room to get any attention as it has been the ‘dumping ground’.

pantry1

The pantry has been a danger zone from day 1. It isn’t just the angle of the photo above – it really does have a lean on it. And that’s as far as the pull-out mechanism could safely(?) go, which means accessing anything inside it was awkward – especially for the fixed shelf right up the top. And then random pieces of broken plastic and steel fittings started springing off it somewhere, just to add to the level of risk of opening the darn thing. I wanted to do something about that cupboard from when I first moved in, but it is an awkward size – 45cm wide (about 42cm internal width) and about 60cm deep. Most cupboards are 40, 50, 60 etc. not 45cm. So it took a fair bit of searching to source a solution – individual pull-out shelves that came in the right size. Thankfully they did exist! Then I had to have two clear days to take the old pantry apart and install the new shelves and re-hang the door. That was last weekend.

pantry2

First, everything had to come out. I used the new wire basket shelves to stack the contents into on the dining table. The new baskets are slightly wider than the old ones, and much sturdier.

pantry3

Then I had to take the door off the front – it weighs about 16kg (I needed to know that for the hinges later) was held on by just five screws – but had about 12 holes drilled into it as someone clearly had problems when they installed it (the door was also catching before but doesn’t now so I think it was crooked!). Then the pull-out frame had to come out – and it was held by 10mm screws that must have only barely had enough grip on the particleboard. And it had originally been installed backwards – there were already filled holes in a mirror pattern to the ones I now needed to fill. Had I known how little had been holding up the pantry, I would have been terrified to touch it! Anyway, gone now. Lots of holes to fill.

pantry4

Then in with the new shelves. I was very relieved to find they fit perfectly, though I didn’t check the sides walls of the cupboard were exactly parallel – the width is a few millimetres wider at the back, so fitting each basket was a bit tricky, but works. I gained an extra “shelf” on the floor of the pantry where the old rail had been and I made the first pull-out shelf high enough that items like oil and spaghetti would fit (some of these things have be stored under the sink until now).

pantry5

All the shelves and all the food! The last part was the door. This took the most time because I had to hand chisel out the recess for each hinge (which took about five hours!). I also had to measure very carefully (and repeatedly) so that the door would be in the right position.

pantry6

I managed to slot the door back on and get it lined up perfectly. For the moment the handle is still in the middle. It is a little awkward, but if I move it across to the side, I will have two holes in the door that I will have to do something about.

The next stage of the kitchen improvements goes to my strata AGM next month – extending the tiling. Actually, I can’t match the existing tiles, so pulling up the current tiles and retiling a larger area. Then the temporary island bench will be replaced by a permanent island (with new cutlery draws to replace the ones I’ve removed) and I will replace the tile splash back (more than half the tiles are cracked). I’m expecting that to take at least until July (tiling in the Easter break; island bench in the mid-year break).

5 Jan 2015

Potato crop 2014

Posted by jenwren. Comments Off

I like tracking what has happened in my garden because it changes so rapidly that I forget what it looked like and what worked and what didn’t.

One learning experience has been growing potatoes over the last six months. I bought two planter bags – one for me and one for my Mum – and we split a 1kg packet of Ruby Lou seed potatoes between us. I actually didn’t use all of mine as I thought there were too many for one planter bag, and passed a few on to my brother for his garden. We received the seed potatoes in July – as soon as the supplier made them available. I put mine in a dark place in my laundry, and after they started sprouting in August, they went into the planter bag.

In September, they were coming up. But the one in the centre and to one side were much slower than the others – maybe as those parts of the bag were cooler.

spuds1

By October they looked nice and healthy, though those last two to get going were slowing down the rate at which I could add more potting mix and raise the sides of the bag as I didn’t think I should bury them completely.

spuds2

Not long after the photo above, those two stragglers suddenly took off and became the tallest two plants. But none of the plants ever branched or filled out as I have expected them too. And when we got a burst of horribly hot weather in November – bam! – all but those two stragglers dropped dead. Looking back through the photos I took, I forgot to take any of the dying plants. At this point I stopped putting any more soil in the bag – it never did reach the top. Then the other two plants started to look poorly, and finally by Christmas the last one – in the centre of the bag – started to die off.

I should have done it last week, but today I finally dug up the contents of the bag to see if I had any potatoes. My expectations were low. For much of the digging I found absolutely nothing. Then finally at the level of the first addition of potting mix and below I found the potatoes.

spuds3

A total of eight potatoes from six plants. Not exactly stunning and hardly worthy of the hessian bag I had in preparation of storing some of my harvest. Some of them had the early signs of shooting. Maybe if I had left them, I would have had a second round of growth until Winter and a better yield? But more likely another round of hot weather this month or in February would have killed them off again.

spuds4

It will be interesting to try eating them as I’m sure the heat that killed the plants has affected some of the potatoes. Many of them have a crackled surface on one end.

If I try again this year, I would plant the seed potatoes higher in the bag, since most of the potatoes were not far from the level of the seed potatoes, and I have a greater chance of reaching the top of the bag with added potting mix. I should probably make an effort to rotate the bag so that all sides are warmed by the sun evenly, so no plants lag behind and slow down the filling of the bag (I don’t know about placing one in the centre or not as ultimately, that plant appeared to do best…). The bag also needs more drainage holes as the bottom 10cm was putrid. The bag was sitting on top of a plant trolley on castor wheels so that it could easily be moved around my terrace. The water that came from the bottom of the bag was also staining the tiles, so I should have placed a saucer underneath to catch the drips. And I should have moved the bag further undercover when the hot weather hit as the terrace simply became too hot for the plants to cope.

14 Dec 2013

I Played Yarn Chicken and Lost

Posted by jenwren. Comments Off

In December 2011 I started a crochet blanket from yarn (Bendigo Rustic 8 ply) I dyed myself in six colours. I’ve worked on it off and on, with other projects in between, but in the last 3-4 months I’ve pushed on to try and finish the blanket – before it reaches its second birthday!

I reached a point at which I thought I did not have enough yarn to make another row of hexagons, so finished off the end of the blanket with some half-hexies, weighed the amount of yarn left, then started on a border. The idea was to use all the existing yarn to make as much of the border as possible, and if needed, dye up more yarn in one colour to complete it if it was not deep enough. I reached the last colour with just under two rounds of the blanket for the ideal border to go. I knew what I had left wasn’t going to go around twice, but if it made it around once, I’d settle for calling it done. It was a will-I-won’t-I all the way…

yarnchicken

I played yarn chicken and lost.

I had just 20cm to go – from where the crochet hook is to the top right of the pink-bordered hexie – where the grey and brown of the border meet. So close!

Time to dye some more yarn and finish the border properly with that 20cm plus one more round… Problem is, my dyes and dyeing equipment are still packed from my house move in July. That’s them in the middle box on the bottom layer…

sixboxes

I could unpack the box, but there’s nowhere to unpack the box to, because there are quite a few rearrangements yet to occur in my new home. See, this unit was rented from when it was new, about 9 years ago, until I bought it. The previous owners had done nothing to the place. Nothing at all to make it liveable. No fly screens. No screen doors. No gate on the side of the terrace. And no storage enclosure securing the storage area from the car spaces in the communal garage. Consequently, without adequate ventilation, there has been condensation issues in the main bedroom (that will be the first room I eventually repaint, but that is a fair way down the long list yet!) and no secure storage space outside either on the terrace or in the designated storage area.

I have had the ventilation seen to by installing screen doors all over the place and a security screen on the study window. Though that took until late October due to issues getting permission from the executive committee of the strata (they’d lost the key to the letterbox *facepalm*) then obtaining a quote and waiting weeks for manufacture and installation. Here’s some of them during installation:

screendoors

I’ve also installed better locks all over the place (which already prevented an attempted break in on one of the terrace doors), replaced the kitchen tap mixer that was totally buggered, and replaced the split system air conditioning (thanks to an unexpectedly dead system on moving in). On Monday, an electrician is coming to put up a ceiling fan/light in the main bedroom and put an additional powerpoint inside the storage cage so I can move the freezer out there. Which leaves two main outstanding items of immediate need – the gate and the storage cage.

storagecage1

There’s not a lot you can store in an unsecured storage area – consequently, since moving, I’ve had a lot of stuff sitting in my parents garage (which my Father is constantly reminding me about!) and more stuffed into various places inside my unit. I approved a quote for the storage cage in late September. In early October, before term commenced, I had more precise measurements taken by the firm to manufacture the side panels of the cage. In late November they came to install the cage. They got one panel up:

storagecage3

But the other panel had been manufactured backwards so that the door was in the wrong position.

storagecage2

They haven’t yet come back with the remanufactured panel. Hence I can’t unpack the box (the dyes will live in a locked cupboard in the storage area) and so I can’t dye up the yarn and finish the blanket. (If you’re wondering why the panel doesn’t just go straight across the front of my car space, it’s because there’s a passage retained to my “back door” – I enter my unit from the storage space through a door in the laundry. The other panel will be where the plant pots are covering the bolts already placed in the concrete slab.)

And the gate? Well the one quote I finally obtained after trying four different tradies came in only $100 less than the whole storage cage (that’s for a gate about a metre high and a metre wide!). I’ve had it with tradesmen and trying to get quotes. I’m building the damn gate myself!

14 Oct 2013

The Day of the Triffids

Posted by jenwren. 1 Comment

I’m really glad I decided to document the growth of the garden because the rate of growth is astonishing. I’m not sure if I’m growing tomatoes or triffids, but I spread sugar cane mulch around the plants on the weekend, and I simply can’t get in between the tomato plants to mulch them!

veggieendoct13

Up the “natives” end you’ll have to take my word for it that the Grevillea, Philotheca and Rulingia are still there. Actually, I moved the Rulingia nearly a metre – the vegies are doing so well that I decided rather than the 50/50 split of the garden bed I originally laid out, I need some more room for the veggies. When the daisies have finished, I will expand the veggies into another metre of garden bed.

nativeendoct13

The Philotheca is proving the most difficult to locate, but it is still there, still growing.

philotheca3

A week ago, the paper daisies were being attacked by aphids and I decided to let it go and hope some ladybugs moved in.

aphids

At the time I did find one ladybug. This week there were four ladybugs and far fewer aphids. My laziness pays off again!

ladybug

The tomatoes have been flowering prolifically for over a week already. The daisies are on the cusp of blooming. Here’s the most advanced bud:

paperdaisy1