Monday, 16 January 2012

Repairing a dying motherboard

We have two servers at our house, one is for MythTV while the other is a traditional domain controller. One day the domain controller stopped responding, it turned out the motherboard was dying.

Like any good geek I used this opportunity to upgrade the hardware but I lazily left the faulty motherboard on a desk and forgot about for several months. A few days ago I picked it up and happened to notice a handful of bulging capacitors.

I've read many tales of capacitors failing and how replacing them can bring electronics back to life but never had first hand experience. I saw this as my opportunity to attempt something risky... without risk.

I ordered a bunch of replacement capacitors, some no-clean flux and solder wick and sat back patiently awaiting their delivery.

Sunday, 29 August 2010

CatsEyes - Standalone Units

One step closer to a finished product, I have now put together most of the components for the near-end device. All that remains is to add two microswitches, a power switch and the battery holder.

The two microswitches and the nine LEDs need 11 general purpose input/output pins, while the Value Line series microcontrollers only have 10. Rather than using a shift register or any other additional IC to drive all the LEDs I decided to re-purpose the RST pin as an 11th input. The switch on this pin creates a non-maskable interrupt which I have programmed to the mode toggle function.

Friday, 20 August 2010

CatsEyes - Video Demonstration

So I've just managed to snatch 5 minutes to take a quick video of the CatsEyes project I'm working on now. As I explained in my previous post it is a fun little project to test continuity in all eight conductors of an ethernet cable. If a shielded cable is plugged into the device the shielding is also tested for continuity.

The finished product will have three simple modes of operation, slow, fast and manual. These reflect the speed at which the LEDs change. Slow is 1Hz, fast will probably be 3Hz and manual will only change when a button is pressed. Manual will be a particularly useful mode when trying to fix a flaky connection on a single wire in a patch panel. The three modes will be toggled by way of a 2nd switch. With a 3rd switch used to turn the device on or off.

Thursday, 19 August 2010

CatsEyes - A Cat5/6 Cable Tester

At the moment I am part-way through a self-installed CAT6 network at home. I have chased the walls, buried the conduit and re-plastered. I am now on the verge of running the cable and lighting up the network. To be sure all eight connections at both ends of the 22 network cables I am routing (352 connections in total!) are wired properly I need a cable tester.

There are obviously the commercial options. These range from the really low quality units for £5 from eBay up to the seriously exotic Fluke devices which start around £700 and head skywards rapidly. With that in mind I have decided to build my own. My needs are quite basic, to be fair the cheap eBay unit would do. But I reckon I can build something more compact, sturdier, and chocked full of geek-cred. I call it CatsEyes.

Saturday, 14 August 2010

Beyond The Development Board

I was just asked a great question in response to my YouTube clip of the Time Lord demo: "Will the programmed micro work without the launchpad kit?". I was just going write a quick 'yes' in return since my next project revolves around that ability.

Yet as I hovered over the 'Post' button I realised this was merely an assumption; I had never tested it for myself. So I pulled out some jumper wires and quickly connected the Time Lord chip to a single LED and a battery pack as a quick proof of concept.

Monday, 9 August 2010

Free Samples From TI

This morning I was prematurely awoken by the postman drumming on the front door. Just for a change it was not some frivolous jewellery purchase my wife had forgotten about but was something far more exciting - a delivery from Texas Instruments!

Not only do they sell us the LaunchPad for a rediculous $4.30 but they also have a free samples program. Naturally the higher value products are either not available as a free sample or must be ordered through a sales rep. Presumably to confirm your likleyhood to return their cost in a future order but the MSP430 chips are cheap enough to be included in the program.

As I mentioned in my first post, I am a software guy. I have no experience with electronics, no training, nothing. I highly expect to break things all along the learning curve. So the first thing I added to my basket was a spare of each chip (MSP430G2211, MSP43G2231).

Sunday, 8 August 2010

Time Lord - My First Project

After flashing one of the many 'hello world' demos into my MSP430G2231 I needed a project which would challenge and reward me in equal measure. With that in mind I conceived to build a game which would require no extra parts; just the LaunchPad and the MSP430.

I wanted to gain a little experience programming LEDs, switches, timers and interrupts. The first workable idea encompassing all these that came to mind was a simple time-lapse guessing game. The premise is to accurately guess when a parcel of time has passed by pressing a button.