Ask Slashdot: What Is Your Most Awesome Hardware Hack?

An anonymous reader writes: Another Slashdotter once asked what kind of things someone can power with an external USB battery. I have a followup along those lines: what kind of modifications have you made to your gadgets to do things that they were never meant to do? Consider old routers, cell phones, monitors, etc. that have absolutely no use or value anymore in their intended form. What can you do with them? Have you ever done something stupid and damaged your electronics?

Comments

The last time I custom built a PC.

[GoodNewsJimDotCom]

I either used Newegg.com or pricewatch.com. I ordered all my parts custom to save a couple bucks and it was good to run the latest 3d games. Everything came in the mail and I was happy... Until I realized I forgot to order a case. And not to be defeated, I took the UPS box it was shipped in, and carved out port holes. It worked well as a case. The only downside is I couldn't leave my computer on overnight to automatically play video games for me because I worried about it catching fire.

Home built auto answer modem

[dlingman]

Only having a 300 baud acoustic modem and a Tandy Color computer 2, I still wanted to run my own home written BBS. Wound up running the phone line through the cassette relay control on the Coco2.

All night long, Click, see if someone hit return at least one, click - hang up. Click - pick up, watch for return. Click - hang up.

Must have driven Thunder Bay Tel completely nuts trying to find out why someone would keep picking up and hanging up every 5 seconds or so for weeks on end. This was back in 1984. The BBS lasted about 2 years and did have a fair number of people connect in to it.

EBike

[Synon]

I built an electric bike powered by old laptop batteries I collect dead laptop batteries from my employer, many of them contain lithium cells that look similar to AA's called 18650's and it's usually just a single bad cell and the rest are good. I put enough in series to give me 48v and enough in parallel to give me 50 miles of range (about 160 cells). I connected the cells together using nickle strips and a tab welder I built from an old microwave transformer. The microwave was covered in stainless steel so I cut that up and used it to build a battery box that fits perfectly in the front triangle of the bike (yes, it's insulated).

Dippy bird and motion sensor

[Anonymous Coward]

My favorite hack of this sort didn't involve electronics at all. The building management that the company I worked rented office space from, installed motion sensors in all the offices, with a system that turned all the office lights off unless someone was actually moving in the office. I was there after 6pm almost every day, sitting quietly in front of a computer (the motion sensors didn't pick this up) so the lights kept going out. I'd have to get up from my chair, walk over to the motion sensor (installed next to the light switch at the entrance of the room), gesture in front of it so the lights would come back on for 1/2 hour or so.

I finally got a dippy bird (https://en.wikipedia.org/wiki/Drinking_bird) and set it up with a cup of water next to the motion sensor so it fooled the thing. I had to put the bird on top of a stack of books to get it to the right height etc. I'd ask visitors why they thought I had put the bird there, and they usually didn't figure it out, but would burst out laughing when I told them what it was for. Still a fond memory.

Wired to wired+wireless headphones.

[Khyber]

First, the pictures - http://i.imgur.com/moKxZEU.jpg and http://i.imgur.com/XCtxuqg.jpg

Old, cheap $3 pair of Cube headphones found at Big Lots. Had them for years, cabling finally gave out. Came across a broken Polaroid PBT598 bluetooth speaker set, literally the only thing intact was the gumstick amp/bluetooth board, and even then it had damage, it having fried a couple of SMT capacitors, the battery and speaker trace pads were missing.

So, first order of business, get the SMT caps replaced. Easily done - just salvage components from various boards I've got around the house. Slightly trickier was exposing traces and fresh metal to solder to for battery and speaker connections. Making it fit required Dremel and hot glue work due to the shape of the headphones, and as a result the thing does look like a total hack job on the case itself.

But if I want to drown the world out in its entirety, 2x3w strapped to my head certainly does it. I can't hear my garbage disposal, vacuum cleaner, or even the neighbor's loud rap music. Volume has to be kept at pretty much 25% as anything higher, while clear (up to about 60%, then the poor speakers begin to distort) simply hurts.

Photometer on Apple ][

[Port-0]

This was a long time ago, but I wired up a photometer (counts photons) to an Apple 2 joystick port, then wrote a tight 6502 assembler timed loop that would count pulses on the joystick button input. It would accurately read over 50,000 button presses per second, which was good enough to do variable star photometry. I also wrote an applesoft basic program that assisted in the process of variable star photometry and used the assembler routine to read values from the photometer. By connecting the photometer to a telescope and following directions of where to aim the telescope given by the software, it could be used to observe and graph brightness of variable stars over time. Also could be used to calculate the angular velocity of asteroids. This was is the days before extrasolar planets were found, but similar in principle to how that is done. Though the objects we were looking at were orders of magnitude brighter than the brightness fluctuations observed to find planets.

Re:I fried a bot

[PRMan]

I did the same thing at a Halloween party at church. I was using 2 force feedback driving wheels playing Daytona USA networked on the Nebula2 emulator. My daughter plugged the wrong power supply into the driving wheel and tons of thick white smoke came out of it. It didn't work at all. We laid hands on it and prayed and it worked for the entire night and still works to this day!

Garden hose

[endoboy]

Hurricane Sandy in 2012--
a foot of water in the basement and climbing.
Not a pump to be had-- hours of phone calls revealed that I was last in line at the sump pump store; even if I could have gotten a pump there was no electricity.
Realized that we lived on a hill; set up a gravity siphon using 200' of garden hose.

Woke up the next morning to a dry basement, power came back a few hours later.

My hacks from long ago

[ka9dgx]

1. I was told that Unix couldn't dual boot with MS-DOS... so I patched the boot sector to load an alternative version of itself into RAM before system start if an unused bit was set (thus enabling DOS to boot)... so I could reboot back and forth... sometime around 1985.
2. Built a box with a Z80, 2764 EPROM, A/D converter, speech chip and a hacked together telephone interface... had 4 inputs and read the voltages of each to the caller on the phone, twice... then hung up.
3. Wrote a Forth for OS/2 in assembler... because I was told you couldn't write assembler programs in OS/2.
4. Built a system out of solar cells behind a filter, to detect infrared laser, and help align laser CATV links, with a companion box to generate a tone to feed into the transmitting laser.
5. Used a bi-color LED as light and sensor to detect a beam break to a reflector. (Green light can be detected by the red LED, but not vice-versa)

Some 2600 hacks...

[TheRealHocusLocus]

(in the jolly days before digital switching)

Friend was diagnosed with cancer and was recovering from chemo in New Jersey some 1500 miles away. She ran a local ballet company for 30 years and it was to be the first time she had ever been away for their Spring performance. I was sound technician at the theater and we cooked up a scheme to telecast the performance to her. There were a several payphones outside, and I grabbed my butt-set and discovered their pairs appeared in the basement. I put a temporary jumper from one across to an unused pair of the theater's Bell 1A2 key system so it would appear up in the sound booth, put a single line phone on it with a simple phone patch (just a 600 ohm transformer, resistor and capacitor) to an output from the mixing board. A co-conspirator drove 30 miles to the house in New Jersey in which she was staying to install another phone patch into a good Hi-Fi amp and speakers. That night just before the performance I hung an 'out of order' sign on the payphone and we dialed an 800 number in the payphone line from the booth and Blue Box 2600/MF'd the call over to the New Jersey house, and patched in. During the performance one of the dance instructors sat in the house whispering into a microphone with commentary on what the dancers were doing, which went into the private mix. Cost of call: $0. It was all in place and ready minutes before the performance began, a real high-five moment because we came up with the idea to do it three hours before.

Also lots of explore sessions which I'd do from an empty conference room at the University because there were two phones there and dial-9 local toll restriction was so easy to bypass (it was 'supervised', inject quick local digits before telco dial tone). One call I made in stages: into New Jersey (Atlantic path) -> France -> Tokyo -> Hawaii -> local number (knowing it would return via Pacific path), then finally ringing the extension of the phone next to it. Literally a call manually routed around the world. Quality was awful, my 'Hello' was audible bit it sounded like 'helawk' some 2+ seconds later.

Also various random numbers to confused persons in Moscow, in Cold War days before USSR direct dial was permitted from the USA. So you bounce through France. Bouncing between UK/France a couple times then back home was loud, echo-y and strange sounding, the Brits liked their trunks piping hot.