Motorcycle Alarm
Posted on August 19, 2021
(Last modified on August 20, 2021)
| John Morris
Apparently one of the local bike thieves was eyeing up the bike. Certainly a car was driving down the road, crawling opposite the bike, and then driving off again. Having had one bike nicked I didn’t much fancy losing another. Thus we had to make the house look a lot more secure in a hurry; and the shops were closing that evening and not reopening till Tuesday. For it was the New Year.
[Read More]Sunrise Lamp
Posted on August 19, 2021
(Last modified on August 20, 2021)
| John Morris
Every project is a prototype, which calls out for a second version avoiding the mistakes of the former. The trick is to give the prototypes away; then one has a legitimate excuse to make another—and one gains an (undeserved) reputation for generosity to boot. After the quick sunrise alarm clock various things happened, including a ’two week lockdown’ to build up capacity in the NHS, which turned into three months. Thus I was stuck in one part of London, and my fiancée in another, and the streets were patrolled by Dobermans with £10,000 fine notices stuck to their teeth.
[Read More]Quick Sunrise Alarm Clock
Posted on April 14, 2020
(Last modified on August 19, 2021)
| John Morris
This was a sudden impulse last summer: I’d seen a ‘sunrise’ alarm clock (which fades on slowly to simulate sunrise, theoretically bringing you out of deep sleep naturally and waking you up gently). My sister mentioned having difficulty getting up and needing multiple alarm clocks. Ergo.
First thought: where to get the light? I had a look in the LED parts draw, but it was disappointing, as was the draw of old led torches and bike lights.
[Read More]Networked Clock with Hands
Posted on January 12, 2020
(Last modified on August 13, 2021)
| John Morris
Dad rather liked my clock. In fact, he went looking for ‘a clock with hands and an adjustable chime’. Which, of course, made me wonder whether I could make one.
The first question was the hands: I liked the leds at the front of mine, and didn’t see the point in moving real hands around with a stepper motor or something of the kind. A digital clock should, I think, look digital.
[Read More]Vertical Etching Tank
Posted on January 12, 2020
(Last modified on August 13, 2021)
| John Morris
I don’t much like PCBs, but I like wiring ICs up even less. Up till now I’ve made boards with the toner-transfer-and-any-old-container method. The trouble is that I hate making up ferric cholride and always make the bare minimum, and during etching the concentration falls off, the rate slows, and you get poor definition and damage. So I decided to make a proper vertical etching tank, big enough to do a large board and still not run out of etchant.
[Read More]Networked Alarm Clock
Posted on January 12, 2020
(Last modified on August 13, 2021)
| John Morris
This project began when the noise of the ethernet switch opposite my college room became unbearable. I picked the room for the view, which was sublime: the valley falls away so steeply you can see right down, over the trees, to the river, and climbs again the far side in a steeply wooded bank over which the pigeons perform what I can only describe as buzzing runs on the squirells. In the distance, the rolling hills, at night the moon and by day the sun—morning and evening, opposite corners of the window.
[Read More]Radio repair
Posted on December 2, 2018
(Last modified on August 13, 2021)
| John Morris
The radio we use in the kitchen to make washing up bearable stopped working. Specifically, it wouldn’t turn on, but the power LED was constantly flashing on and then fading off. What makes me think the power supply might have died? Lo and behold, after purchasing a cheap multimeter (it’s incredible how cheaply one can get some things now: in ten years the price of test equipment has plumetted): the ‘8v’ output was about 3v, and the ‘15v’ output was 0v.
[Read More]Clap-clap switch
Posted on September 19, 2018
(Last modified on October 5, 2020)
| John Morris
I’ve always thought of those clap-activated switches as a bit of a gimmick—after all, you can always just move the lightswitch if it’s that hard to get at. But currently my mother is hobbling around on crutches, and it suddenly struck me that turning the uplighter on from the doorway would be handy. A rummage through the junkbox found a board—I think from an old washing machine—full of relays, and 5v relays at that, so no need for a voltage multiplier to turn the relay on.
[Read More]'Off and on again' remotely
Posted on August 2, 2018
(Last modified on August 13, 2021)
| John Morris
The internet in Durham, which was allowing me to use the workstation there remotely, has gone down; support tell me to ’turn it off and on again’. But obviously I can’t do that remotely. Ah well, it wasn’t really needed. But what if it were? I’ve run servers over unreliable wifi links with good uptime before, with a failsafe script which rebooted everything if it couldn’t ping the gateway for too long—and looking at the logs, sometimes it was needed.
[Read More]Display Board
Posted on July 31, 2018
(Last modified on August 13, 2021)
| John Morris
I started this peice of test equipment when I was about 15, I think, built the timebase with enthusiasm, the counting chain with a bit less, and then wondered how on earth I was to attach the 7-segment displays. Surely not one wire each?! So the project languished, and eventually got relegated to the shelf without ever being finished. All I had was the breadboard and two schematics which nearly corresponded with what was in front of me:
[Read More]