peterland

Big Muff clone completed

noreply@blogger.com (Peter Tangney) — Wed, 14 Mar 2012 19:33:00 +0000

I've finished my clone of the well-known Big Muff distortion pedal. I painted it with some grey primer and then with a design of Cardiff Bay as I have a vague notion of making myself a range of Cardiff-themed effect pedals. Total cost in parts was around £16-17 and a lot of that is because I bought the extortionately expensive switch from Maplin instead of pretty much anywhere else.

It sounds quite a lot like the original as far as I can tell. It is REALLY LOUD, and is unfortunately not very useful for playing in our apartment as I get the feeling I must be annoying the hell out of the neighbours, even at low volumes.

Next up will be a Small Clone clone. A clone² I guess. It's a chorus pedal that was used by Kurt Cobain on Nevermind apparently. I've ordered up the parts from far-flung ebay sellers across East Asia, so they'll take at least a couple of weeks to get here, which gives me plenty of time to change my mind and start and abandon another several projects.

Big Muff clone

noreply@blogger.com (Peter Tangney) — Sun, 11 Mar 2012 16:25:00 +0000

This weekend I've been down at Cardiff Hackspace building a clone of the well known Big Muff distortion pedal, first getting it working on a solderless breadboard:

Then I built it on some copper stripboard, but for some reason couldn't get it working. After checking, rechecking and re-rechecking, I finally spotted the problem:

See the problem? No?

There it goes - at one of the points where I'd used a drill bit to break the copper track I hadn't quite broken it completely. Those holes are 2.54mm apart so the bit of copper that was left couldn't have been much more than 0.2mm wide, but it was enough for electrons to squeeze through and stop it producing any sound.

Once that and several other problems were sorted, I brought it home and tried it out. It doesn't sound exactly like the original, but it has a nice tone with loads of gain. Hopefully this week I'll put it in a nice enclosure.

Soldering iron power LED

noreply@blogger.com (Peter Tangney) — Sat, 03 Mar 2012 10:04:00 +0000

For xmas a couple of years ago my parents bought me a nice temperature-controlled soldering station which I've been using to build all my half-completed projects. It works great, but it has one small problem: the LCD display isn't backlit so, at a glance, it isn't obvious that the power is on. This isn't normally a problem but if I'm working on something that means I'm soldering something and then going back and forward to the computer to program an Arduino or whatever, it's possible to forget the soldering iron is on.

And then go to bed.

And then go to work.

And then come home and find out that there's been a 50W desk-mounted heater on for 24 hours and somehow we still have a home and not a smouldering ruin.

The solution to this problem is trivially easy - mount an LED on the front to make it obvious that the iron's on. First thing we need to do is open up the soldering iron and find a power source to hook our LED up to.

This is the main PCB for the iron, and at the top left is an LM7805 linear voltage regulator that supplies the 5v to power the control circuity. Perfect and has long leads that we can solder to. If you're looking at the front of the LM7805, the three leads are Vin - GND - Vout.

A quick check with the multimeter to confirm.

I come to a small problem here - how am I going to solder on the inside of my soldering iron? I briefly consider using the soldering iron itself and then remember that I have a butane powered soldering iron for just these sorts of occasions:

I dig out a 5mm red LED and find my LED calculator to work out what current limiting resistor I need. Looks like 150 ohms will do the trick, which is one of the several values I have. 10 minutes and some dremel action later and we have this:

I should have used some heatshrink, but I couldn't find any. It should be ok like this though. The LED fits in pretty snugly but for peace of mind I might stick some hot glue on the back to hold it in. But does it work...?

Power off

Power on!

Success! And all done before breakfast on a Saturday. Quite good fun in the end, and if it stops me from accidentally burning down the house, well that's just a bonus.

Skittle sorting

noreply@blogger.com (Peter Tangney) — Wed, 29 Feb 2012 17:00:00 +0000

Extremely important Skittle sorting prior to making Skittle vodka, which was amazingly tasty and alarmingly drinkable. Especially the orange flavour. We passed the cheap and nasty vodka through a Brita charcoal filter before infusing it with the Skittles, which I think made a bit of a difference. It certainly made a difference to our filtered water for the next couple of weeks as it had a bit of a vodka flavour until we got around to changing the filter.

Oscilloscopes

noreply@blogger.com (Peter Tangney) — Wed, 29 Feb 2012 10:52:00 +0000

This is a nice 20MHz analog scope that was donated by UWIC to Cardiff Hackspace. It's awesomely retro but works great. I don't know how I ever managed to do any electronics without access to an oscilloscope. I keep meaning to use it to display some graphics. I even got around to getting some DACs (Digital to Analog Converters):

Yeah, soldering that onto the breakout board was quite tricky. The main body of the chip (the black bit) is only 1.75 by 1.3mm big. I haven't got around to doing any more than that, so it's in the pile of ideas and half-completed projects.

Fire is the Purifier

noreply@blogger.com (Peter Tangney) — Tue, 28 Feb 2012 20:35:00 +0000

LED forest

noreply@blogger.com (Peter Tangney) — Tue, 28 Feb 2012 10:06:00 +0000

Yes, that is quite a lot of LEDs. I did this for a test of my still-in-progress sunrise alarm clock that I started back in October and now will almost certainly not get around to finishing before winter is over rendering the whole thing completely unnecessary.

Ahh, but it looks so pretty.

Allotment shed building

noreply@blogger.com (Peter Tangney) — Mon, 27 Feb 2012 23:08:00 +0000

This is our amazingly spectacularly awesome almost finished shed we've built on our allotment. Hewn from a pile of pallets, scrap plywood and doors, with bonus store damaged roof sheeting from B&Q. Doors make remarkably good walls, so we're not expecting to have to replace this in the near future.

This is the largest structure I've ever built, easily overtaking my tree house that I built from 1993-97. I have not yet broken any bones in the construction of this though. I really should scan some of my x-rays sometime....

Anyway, we now (well, ironically, when we put a door on it) have somewhere to store all our tools and various other bits of gardening equipment that we've accumulated already.

Allotment surprises

noreply@blogger.com (Peter Tangney) — Mon, 27 Feb 2012 19:58:00 +0000

So when you pick nice fresh food from your allotment (or, in this case, my Dad's) you should remember that slugs are really good at hiding. This one only made its appearance after a day in the fridge, which was quite surprising.

Reprap Heated Bed Testing

noreply@blogger.com (Peter Tangney) — Mon, 27 Feb 2012 10:39:00 +0000

This is the heated printbed from Iain's reprap being tested after he'd replaced the nichrome wire based heater with some chunky high powered resistors:

Once all soldered together and attached to the build platform with metalised epoxy, we fired it up and checked it out with a thermal imaging camera graciously loaned by my work:

Interestingly, the parts where there isn't any Kapton tape show up as much cooler - not because they are any cooler but because the bare metal is reflecting an IR image of the cold window. Anyway, the heater seems to work pretty well as Iain's reprap is churning out all sorts of interesting stuff.

Mintyboost clone

noreply@blogger.com (Peter Tangney) — Sun, 26 Feb 2012 19:36:00 +0000

This is a clone of Adafruit's Mintyboost that I made to take to Glastonbury last year to keep my phone charged. It's basically the suggested schematic and layout from the LT1302 step-up converter. It turned out pretty well - I like that its not much bigger than the two AA cells it runs on. Could do with a nice 3D printed case for the component side perhaps.

Performance wise, it was a bit disappointing. I think that was quite a lot to do with the crappy batteries we took with us and that were available on the site. I didn't actually test it very much. At some point, I'll get around to doing a proper test with various batteries.

Tree Rabbit

noreply@blogger.com (Peter Tangney) — Sun, 26 Feb 2012 09:48:00 +0000

Got this squirrel at the farmers market and later made a very tasty casserole from it. Not a huge amount of meat on it but has a good flavour.

noreply@blogger.com (Peter Tangney) — Sat, 25 Feb 2012 22:25:00 +0000

I would be a terrible mime.

noreply@blogger.com (Peter Tangney) — Fri, 24 Feb 2012 19:37:00 +0000

Unnecessarily robust reclaimed pallet-wood table, built for our allotment.

noreply@blogger.com (Peter Tangney) — Thu, 23 Feb 2012 20:13:00 +0000

Optimal use of frying pan space when making fish finger and black pudding sandwiches.

Replacement beer fridge thermostat

noreply@blogger.com (Peter Tangney) — Thu, 23 Feb 2012 13:26:00 +0000

This is an Arduino-based thermostat I made for the beer fridge that Tina found in the rubbish outside our flat. It worked fine for a few months and then stopped - the mechanical thermostat had crapped out.

Coincidentally, I had a thermocouple and a MAX6675 thermocouple amplifier hanging around that I'd purchased with my Sparkfun free day winnings so I threw this together and installed it into the space where the old thermostat had been. Since I had heaps of I/O pins left I added a 7-segment display to display the temperature on the front of the fridge.

It works great, and is currently installed at Cardiff Hackspace, cooling our beers.

noreply@blogger.com (Peter Tangney) — Wed, 22 Feb 2012 21:04:00 +0000

Kittehs love books

noreply@blogger.com (Peter Tangney) — Sun, 19 Feb 2012 22:57:00 +0000

Nice scope trails.

Lithium Ion battery (near) disaster

noreply@blogger.com (Peter Tangney) — Mon, 11 Apr 2011 19:06:00 +0000

Lithium Ion battery failures are well documented. There were have been many fires and explosions and Sony recalled millions of laptop batteries in 2008.

My phone battery has been getting steadily worse and today on my way to our Bristol branch for some training my phone turned off even though it had been fully charged an hour before.

I took out the battery to reset it and immediately noticed a distinct bulge in the middle of the battery. Here's a picture of the measurement across the middle of the replacement battery that I've had for months but not got around to putting in:

And the old one:

Given that this is often the first sign of failure, and that the next sign is failure tends a bit on the firey side, I might just throw this battery away.

Wild Wales

noreply@blogger.com (Peter Tangney) — Tue, 09 Mar 2010 21:40:00 +0000

I've just finished reading Wild Wales, by George Borrow, which I picked up in an Oxfam bookshop for £4.99, not long after we moved over here. I know this because I've been using a train ticket (Day Travelcard between Earlsfield and zones 1,2,3 and 4; dated 22 October 2006) as my bookmark, which is quite convenient.

The book, first published in 1862, is a telling of Borrow's (mostly) walking tour of Wales, in 1854. He starts off in the north and covers much of the country, inexplicably missing out most of Carmarthenshire and all of Pembrokeshire as well as Cardiff.
I won't give a full review, but it is an interesting look at Wales, right at the beginning of its industrial boom. I particularly appreciate this passage, describing his arrival at Merthyr Tydfil at night, at a time when (I believe) my great-great-great-grandfather, Thomas Hughes, was living there:

Turning round a corner at the top of a hill I saw blazes here and there, and what appeared to be a glowing mountain in the south-east. I went towards it down a descent which continued for a long, long way; so great was the light cast by the blazes and that wonderful glowing object, that I could distinctly see the little stones upon the road. After walking about half-an-hour, always going downwards, I saw a house on my left hand and heard a noise of water opposite to it. It was a pistyll. I went to it, drank greedily, and then hurried on. More and more blazes, and the glowing object looking more terrible than ever. It was now above me at some distance to the left, and I could see that it was an immense quantity of heated matter like lava, occupying the upper and middle parts of a hill, and descending here and there almost to the bottom in a zigzag and tortuous manner. Between me and the hill of the burning object lay a deep ravine. After a time I came to a house, against the door of which a man was leaning. “What is all that burning stuff above, my friend?”
“Dross from the iron forges, sir!”
I now perceived a valley below me full of lights, and descending reached houses and a tramway. I had blazes now all around me. I went through a filthy slough, over a bridge, and up a street, from which dirty lanes branched off on either side, passed throngs of savage-looking people talking clamorously, shrank from addressing any of them, and finally, undirected, found myself before the Castle Inn at Merthyr Tydvil.

Delightful.

GPS: Working! (well, nearly)

noreply@blogger.com (Peter Tangney) — Mon, 22 Feb 2010 20:49:00 +0000

So I got my GPS module working.. sort of. After stuffing around with it for ages it turns out I was just being daft, and after fixing several obvious problems in both hardware and software I was getting lovely NMEA codes out:

$GPGGA,202429.009,0000.0000,N,00000.0000,E,0,00,0.0,0.0,M,,,,0000*08
$GPGSV,3,1,12,27,89,000,33,16,66,000,,15,54,000,,25,50,000,*7C
$GPGSV,3,2,12,14,31,000,,19,28,000,,13,24,000,,17,21,000,*7F
$GPGSV,3,3,12,23,18,000,,05,08,000,,29,01,000,,02,-2,000,*68

The $GPGGA line is positioning data and the $GPGSV lines are data about the satellites we can see. Unfortunately from the flat we don't have enough sky view to be able to get a fix. The GPS is only tracking one satellite which is only good enough to give us the current time as shown in the first line (20:24:29).

Next plan is to write some software to do something useful with the data...

Homemade Toner transfer PCBs

noreply@blogger.com (Peter Tangney) — Wed, 17 Feb 2010 21:40:00 +0000

We've just recently bought a laser printer so I've been trying to make some decent printed circuit boards with the toner transfer method, where you take a reversed printout of your circuit and iron it on to plain copper-clad board, then etch the board and the toner resists the etchant, and the circuit remains in copper on the board.

That's the theory anyway, but finding the right paper is a problem. You need a glossy, waxy paper that will easily come away from the toner when you are done ironing, but most papers just fall apart and you are stuck with half a sheet of paper firmly attached to your circuit-board-to-be.

Many people on the internet seem to use magazine pages, but I have found them to be uniformly rubbish for fine-pitched traces.

For future reference, the following papers don't work:

Buzz (Cardiff gig guide)
Guardian Weekend Magazine
New Scientist
Look Magazine
Cotswolds catalogue
Domino's Flyer.
Tesco "Value" glossy photo paper
and regular Kitchen Paper, which I thought would work well, but doesn't seem to want to release the toner onto the copper.

Liverpool

noreply@blogger.com (Peter Tangney) — Sat, 14 Nov 2009 08:15:00 +0000

So we're on our way to Liverpool for the weekend. Once again, it's a bit of a spur of the moment plan. I like to think that we're decisive instead of impulsive...

Anyway, we're hoping to see a Bridget Riley exhibition while we're there. I saw some stuff of hers in Wellington in 2005 and it's pretty awesome. It's all crazy geometic patterns that mess with your eyes. Unfortunately last time I was quite hungover and it wasn't the best.

Peterland version n+1

noreply@blogger.com (Peter Tangney) — Wed, 11 Nov 2009 19:55:00 +0000

So I've decided to move Peterland over to blogger, in the hope that it'll make me update more often. Whether this will actually happen or not is as yet unclear. Unfortunately all the blog templates are aweful. You'll have to take my word for it that this is the least bad one.