Tuesday, 20 September 2011

Farnell Stuff Review

So I was stumbling around on the internet in a semi-drunken state one Wednesday afternoon (as you do when visiting your sister's pub..) and I discovered I had an email from a nice chap at Farnell asking me to review some stuff for him. My initial thoughts were the result of a head on collision between "it's a phishing attempt/spam" and "FREE STUFF!"
fast-forward a week or two and I now have in my possession some 3 watt LEDs some AA battery holders and some ATMega328s.

Starting with the LEDs, I basically went for the best brightness to price ratio while not being SMT. I chose amber because I have plans for a future project involving these.

Fluff not included. From LEDs

Monday, 5 September 2011

Mouse Repair

Here's an example of getting stuff done and a justification for the heap of potentially useful stuff (lovingly referred to as "crap" by friends and family :P)
Today my boyfriend's 5 year old mouse developed a slight cough dodgy left click switch. While it was amusing listening to the increasing levels of frustration as single clicks turned into quadruple clicks and drag selection turned into time wasting, it needed fixing.

Here's the vintage rodent in question, a Logitech mx3200 series. From mouse
To the crap useful stuff heap!

Friday, 5 August 2011

keyboard circuit diagram

This is more or less the current circuit layout:

From keyboard

Current problems: LCD stays lit and powered while the PC is turned off, possibly due to wake on keyboard/mouse being enabled..

I'm planning to add:

  • a rotary encoder for navigating menus
  • keeping track of stats like words per minute
  • switching backlight power
  • arduino reset button
  • morse code input?

Long term i'm aiming to have the arduino connected directly to USB, but i'm not sure if it'll cope with the extra load..

Saturday, 23 July 2011

keyboard code

I've fixed most of the major issues with the keyboard, so without further ado here be code:

and header file:

There's probably far better ways of doing most of it, the status lights still do nothing and I had to do a rather annoying workaround so that rightctrl+z  works properly (and other key combinations that start with 0xE0)

Advice/suggestions would be brilliant :)

Wednesday, 20 July 2011

Keyboards 4: The LCD of Awesome!!!

The LCD screen arrived today, it was remarkably easy to wire up and get running. I ended up using a couple of the analogue inputs as digital outputs and I've still got 4 pins left over..

I also plumbed in the LED which turned out to be very bright green and tweaked the code to make it flash while the keyboard is sending data. This is almost the most annoying thing on the planet, only second to the American pronunciation of the word "solder".


From keyboard

From keyboard

Cheers to ByVac Electronics for the LCD of awesome :)

Monday, 18 July 2011

Keyboards 3: The Tidying of USB

I finally got round to replacing the usb ports on the keyboard yesterday
I've gone for a standard socket for the spare port on the hub and a mini-b connector for the host connection (i figure there should be plenty kicking around now that mobiles have switched to micro usb)

also: hotglue.

From keyboard

Naturally they're somewhat wonky, I might straighten them at a later date..

Stay tuned for the next instalment: Keyboards 4: The LCD of Awesome
(coming in 2.5+((effort*lazy)/awesome) days)

Wednesday, 13 July 2011

Drill Battery Charger

A few months before I moved to sunny Scotland my dad passed on his nice bosch drill set, which kicked around for a while and now that I want to use it, I discover the charger's dead!

AL 60 DV 1411 charger From drill charger

To the workshop, Batman!

Tuesday, 12 July 2011

toasty modem!

BT business broadband modems run hot (at least the 2Wire ones do). They also have no heatsinks or fans, but then at "room temperature" this isn't a problem.
The problem arises when you put said modem in a smallish room with about 800w of computing equipment and two people. On a warm day the room hit's between 25 and 27°C and the modem gets a little flakey.

Enter: the big fan!

From modem

I chose this one because it runs quite happily on 5v and is nice and quiet, screwed it onto the lid of a spare modem and swapped the lids over this morning. (hopefully) problem solved!

Sunday, 5 June 2011

Noisiest. O-scope. EVER!

I have the world's noisiest o-scope! It's an old ADC-200 computer based parallel interface box. harmless enough.
However, once it's plugged in it emits the most infuriating squeak I've ever heard. It's like it's full of really tiny rape alarms or something.
While it may be a bit low spec compared to a modern scope (20MHz, 10 in dual channel mode), it's a whole 5MHz faster than my vintage farnell DTC12 (wooo...) and it's PC based therefore a storage scope (YAY!!!!)

I'm going to do a bit of poking around and see if this is normal or fixable. Or I might just wrap it in foam and operate it from a draw...

Tuesday, 31 May 2011


I've added some switches for turning the peripherals on and off. Mainly because I got fed up with having to unplug the whole thing every time something threw a wobbly, the memorystick got unmounted/ejected or if the USB port it was plugged into wasn't providing enough power.

Aren't they beautiful! (erm.. no)
from left to right: nothing* Program protect*, Storage, Keyboard
*this was going to be the FDTI but the TX, RX and DTR lines where enough to keep it powered :(
*isolates the DTR line

Wednesday, 25 May 2011


I'm not entirely sure how to release the code for this, maybe on Google code under the GPLv3?
Anyway, the last useful version is linked here.


Take one Dvorak using engineer, an unhelpful IT admin, a vintage keyboard and an arduino.
Mix well for 2 weeks and bake for three years at 9000°F

Okay, maybe I didn't bake it (I'm no good at cooking anyway..)

The initial plan was to read the scancodes from the keyboard and re-shuffle them so that I could use a Dvorak layout while the operating system was set to qwerty. This turned out to be pretty simple to do once I got my head round the PS/2 system. I never got round to allowing PC -> keyboard communication, mostly because I can't be bothered (who needs status LEDs anyway?)

Having Dvorak-ifyed it I decided to have some fun and add a random expletive button.