I have this KVM to switch between a PC, Mac, Amiga and linux machine, but it
doesn't switch between Audio .. so with some parts from very old ISA sound and modem cards
i made a little device to connect all the machines to a set of big PC-speakers.
These where the results of trying to measure magnetic fields with the oscilloscope.
With ferrite cores you can only measure AC currents, with HAL sensors which you can find in
brushless motors in optical drives you can measure DC currents and fields of magnets. But
useally they are SMD and tricky to solder to PCBs. However in an old 5.25" floppy drive i found
some HAL sensors that have 4 long pins on one side. So you can make a probe where the tip does
I was trying to record video on a desk, but if you use a tripod then it is always in the way.
So i build this rig, it is basically a couple of table legs with a big base. Some plank holders and
a big aluminium profile with the head of a small tripod mounted on it.
You can use a big reflective windshield protector to light your desk with a high power lamp.
I was thinking about some usb cases to keep backups organized, i actually made some
sketches but did nothing with them. Then i showed them to Joke Belonje who makes all sorts of
boxes .. and she turned the design actually into some very sturdy actuall cases !
I wanted to use the USB port on an MBED controller on a breadboard, but did not want to pull
a HUB apart for a USB connector. So i rememberd i have some of the PS/2 to USB "converters"
from logitech mice laying about. So i pulled them apart and soldered some wires to them.
These are USB B connectors i got from old printers, usefull for if you want to use an MBED,
or power a breadboard by USB !
And i made a little adapter so i can use the cord as a 2 wire battery adapter.
I had this microscope for decades, it was powered by batteries and only had a small hard to replace
lightbulb on the underside. So you could only look at semi-transparant object .. or with a lot of difficulty
look at a chip by putting a powerfull desklight directly against it.
But now I put two powerfull white LEDs on it, which makes it very easy to look at objects like chips.
LPC800 mini board.
NXP send me this nice LPC800 miniboard, but to be able to use it i made some changes.
At first i desolderd the controller and placed it in a socket, so i can use it in a project
Then i added a row of header pins to connect it to an LPCXPRESSO j-link, as i didnt have a 0.05"
cable for the default connector.
And finally i added header pins to plug it into a breadboard like a stamp like device.
Oh .. and of cause i needed to cut the connections on the LPCXPRESSO and add headerpins.
Arduino UNO with a twist.
The Arduino is small (educational) computer which you can get in different formats, like this UNO
in which you can place shield boards to expand it. And versions with headerpins which you can plug
into breadboards. However .. with a little efford you can make the UNO 'breadboardable'.
Remove the atmega328p chip and insert it in a breadboard. Then you need some wiring to connect the
RX, TX, Gnd (,+5v) and reset pin. I made a 2 lead and 4 lead cable for that with header pins on both sides.
And as last you need to add a 16 mhz crystal with probably a resistor and a couple of small capacitors.
As wire length and capacitance between breadboard tracks can be very critical i soldered those all on
a piece of stripboard. Which also frees some breadboard space.
Dont forget a buffer and decoupling capacitor close to the chip or else it wont run right.
Update: This works fine to program and test an arduino program, but when i reconnected power
to the Arduino board the program didnt ran correct, unless i disconnected the reset wire.
This is a little tablet stand i made, which makes it a little easier to develop
software for it. As you can put the tablet next to the monitor while it is connected to PC and power.
Shown with a 10" dual core 1280x800 pixel cherry mobility m-1038 kruidvat tablet on it.
Made from a piece of PC case, some aluminium a bit of profile and epoxy.
This might seem very obvious, its an emptied PC PSU with 12cm (5") fan to suck solder
fumes away. But when i started experimenting i only had a bunch of PC PSUs with 8cm fans and some loose 8cm fans.
The power switch still functions and it has a wal wart connector for power.
I made a little adapter cable with male/female molex connectors to daisy chain it with
other gear on the desk. And some 9v adapters for portable use.
Apparantly fans like this dont have enough power to use some kind of filter.
I also tried to use some PSUs with 8cm fans, but those take up a lot of space on the desk,
i ended up using thosw to blow a stream of air over the desk to blow fumes away from me
as the jet from the PSUs has a long reach .. while they only suck fumes away directly in
front of them.
I have had this solder station for decades, still works great except that the cable is worn.
So i cut pieces of the cable, which improves it a bit. But there are still breaks in the cable.
So where to find a flexible cable with 2 thick wires and 3 thin wires ?
So i tried to make a cable
myself by pulling 5 wires with some use of talcum powder through rubber aquarium bubbler hose and it worked !
Also as i am very near-sighted i tend to take my glasses of during soldering which can be dangerous with springy wire.
So i sort of made instant safety glasses by tracing over red/green 3D glasses on 0.33 mm thick foil and taping the legs on.
There are some great programs out there that turn the line input of PC soundcards into a sort of oscilloscope.
Of cause they have limitations as they can only show AC and have a limited sample frequency, but they also have options that
Analog oscilloscopes dont have like FFT analysys and measuring frequencies. So if you work with low frequensies a lot that can
be a helpfull tool. However .. no one seems to be making hardware for it to connect to anything.
So a long time ago i started making this (i planned to put it in a case but that didnt happen yet) .. it has a couple of 3-way
switches to select sensitivity. And each channel has a couple of female and male header pins for connections.
I made a couple of cable for the male header pins from cables found in old PCs to directly connect to breadboards.
And connected some BNC connectors from old ISA network cards to the female headers for oscilloscope probes.
I also made a little adapter so i can connect the hardware to a breadboard .. as i was experimenting using controllers
like MBED, LPCXPresso and xmos startkit to build a simple digital oscilloscope.
This is a little (FAILED) hack to try to make a continues solder sucker.
It consists out of a centrifugal fan from a popcorn maker, some desert packaging, an old solder sucker
a semi transparant plastic bottle from a cycling suplement i found at the road and some tubing.
The original solder sucker failed as some plastic parts broke. Useally suckers with plastic parts
break after a short while while all metal ones work for decades. So i tried to connect the
business part to a vacuum pump. But there is almost no vacuum. Probably because the tubing is to long
and far to thin. Perhaps some foot operated bicycle tyre pump would be better.
Normally you stick chips in MOS foam .. bigger parts like transistors or regulators don't seem
to stick in that. So i found that you can stick them in thick plastic foam. And also write down connections
on that. So i have a lot of pieces of foam with transistors. Also great for bigger breadboard modules.
I still have an analog multimeter that i have had for decades now and that survived several
digital multimeters. It is still very usefull and might have advantages over digital meters, like it doesnt
need a battery, the read out doesnt jump all over the place and it doesnt have electronics that break.
Over the years i made some small tools for it.
First is an adapter so i can connect 4 devices to it using female headers, each header has ground, signal and 9v.
So i can connect active probes to it to measure things like temperature or magnetic field.
But als connect a scope probe with an adapter, crocodile leads, or leads with very thin needles
(made with pushpins) that actually fit in holes of breadboards .. as normal leads dont fit.
Also i can insert a resistor adapter so you can measure diodes or LEDs.
There is a board with a TL431C from an old PC PSU that acts like a 2.5volt reference source.
And not shown is a BPW34 photodiode adapter to measure IR LEDs (remotes) or UV LEDs to check
how much UV glasses filter.
Some time ago i got a HP vectra PC with severe PSU problems, but as it was a desktop case
with an odd shaped PSU i decided to transplant it to an old server Tower case.
However there was a problem with the motherboard, it only had a custom HP header for buttons and leds.
The normal header with more pins wasnt populated.
With the HP header there werent ground pins next to signal pins or the cables needed 3 pins, while there
was spacing for 2 pins on the motherboard so i made some adapters to connect up all the signals.
RS232c nullmodem cable.
This is a little changeable serial nullmodem cable i made from some discarded serial
mice decades ago. As i needed one and couldnt find one locally.
Someone needed some fans with their wood stove, to blow warm air in the room.
Also the speed needed to be changeable and there was no budget.
So everything is recycled, fans from PCs, an 18V PSU from a very old HP printers.
And an LM317 to control the fan voltage from 7v to 14v. Where R1=100 Ohm .. and R2 is a 540
Ohm resistor and a 470 Ohm potmeter. And of cause a couple of capacitors.
I was testing a bunch of infrared remotes, and while most give a sort pulsewidth
codes which are tricky to decode, i noticed that the pinnacle one gives normal serial signals
with 1200 baud. Which isn't that odd as it was used to control a PC PCI-TV tuner card. And the
receiver used to be connected to the serial port of a PC. So its very easy to use it as input
on a microcontroller. Just connect it to serial port. However reception seems slightly worse
as a normal remote. Looks like it sends 3 bytes at 1200 baud with one stop and no parity bits.
I wanted to make a logic probe for breadboards, but figured that if i use a VU-meter module
i get something like a fast solid state meter that is more versatile as it can display differences
between 5v and 3v.
Now the big trick is to mount it in the transparant cylinder, which was the packaging of a pen.
This is how it ended up.
Stepper motors can be great to move things like mirrors fast and accuratly, however connecting
something to the thick axle might be a problem. Not with a fuse holder !. It holds very tight
A lot of devices like controllers or displays need a voltage of 3.0v or 3.3v, to not need to
remember the LM317 connections or find matching resistors i made this variable regulator with
the same pinout of the old 7805
The device next to it is a resetable fuse from an old network card solderd to some board
Basically if you put more then 1Amps through it it heats up, and increases its resistance
so the current to the circuit is cut off.
This is a little passive device to test remote controls, basically its a light meter made from a little
battery/field strength meter i got from an old radio a long time ago. Its connected to a BPW34 photo diode.
It can also be used to test infrared diodes or photo diodes.
The device next to it i use to test LEDs in, it just connects to a 9V battery or a power supply.
You would think testing LEDs is easy with a breadboard, but you need to find the right resistor and voltage
and its hard to point a breadboard at a test target
9V battery Hack.
Someone had the problem that wireless microphone receivers need 9V batteries, and have no means for external power.
So they asked me to showehow hack some adapter together, like screw the top of a battery to some wood.
After some experimenting this was the result, a battery with its inerts replaced with cardboard and a wire
soldered to the poles.
Just a little I2C bus i made so i can test I2C sensors like the compas or gyro
without having to turn a whole breadboard.
Most phone LCDs have impossible small connectors or copper traces for which its hard to make a connector
so after a while a gave up trying to connect a display just found one with huge copper tracks and soldered
wires to it.
This might be a bit obvious, these are adapters so i can power a breadboard with
Wall wart adapters. Usefull when you don't want to take a lab power suply with you.
I think the sockets came from a very old calculator and a fax machine.
Note that i added a power switch to a wall wart. Might have been more practical to add one
to the adapters too.
Some little adapters to program basic stamps and javelin stamps in a breadboard.
Note that they have two capacitors on the reset line.
One of the basic stamp adapters in use.
A little adapter to add a serial port to a LPCXpresso on a breadboard.
Note that the adapter at the bottom is almost the same as the basic stamp adapters i made,
but this one is to program a basic stamp on a PCB with 4 headers pins (or other pins with the small
adapters) it connects to the little board which inverts the serial signals to 3.3v or 5v depending
on the jumper. You can find the circuit here.
I made it so i can connect an lpcxpresso to a PC and use it with the stampdock software.
I only had some short serial cables but some long phone cables. So i soldered some rj-45
connectors to serial connectors so i can have cables as long as i want.
The cable at the bottom was a null-modem cable i used to connect basic stamps with earlier mentioned
adapters to things like palm pilots.
I made these so i can quickly add a number of LEDs to a breadboard while they take
very little space on the breadboard. And of cause its lets work to wire them up.
And some quick connect LEDs/logical probe for breadboard.
I you put voltage on the right pins of a SCSI terminator you can use it to test LEDs.
Multimeters can take up a lot of deskspace next to a breadboard, so i remembered
i have some small meters from old radios and such. So i added a resistor and replaced the wires
with more flexible ones and header pins to use them on a breadboard.
This might be obvious, but is a little development. I started with soldering header pins to a 9v battery clip.
So you could plug a 9v battery to a breadboard when you need power. But after a number of times plugging it in
the wires started to fray. And i plugged it in once wrong, shorting the pins. Making the battery boil.
So i added a switch !. And after a while just soldered female header pins to battery adapters so the pins dont
short out when they touch metal on your desk. So i made some cables with a switch and male header pings
to connect battery adapters to breadboards. The thing in the middle is a PCB that came from a 9V battery,
it is much sturdier as normal 9v battery clips, and might make a nice 9v battery clip.
These are battery adapters i tried with a 5v step up board to make a very light power suply.
i didn't have an AAA battery adapter, but i had a very cheap radio which seems to work fine as an adapter.
i also tried a CR2032 battery. but it seems to have to much current to power anything with the converter.
Instead of taking devices apart to separate parts it can be interesting to check what
function parts have. These are a 30v to 5v converter from a printer and a headphone amp. from a CDrom.
This is a part of an old printer, the buttons each have a wire. While the LEDs are connected
to a shift register. Actually there was space for two more (hidden) LEDs in the corner left under which i added.
For use on a breadboard crocodile leads are often to long and to stiff. And to connect them
you have to clip them to a resistor or a pin. So i made some custom leads that take less space on a
breadboard and are easier to use.
Also by default a lot dont work as they where clamped badly, so i reworked them to these but with
I have this very old rechargeable drill and the NiCd's gave out completely.
Without the battery its a nice very light drill, so i tried it on a lab. supply with
some sets of crocodile leads. It worked, but the leads got warm and shorted.
So i made some long crocodile leads with thick wire. Great to connect anything to the lab. supply
The metal of cases of old PCs can be very usefull. But you need some nibbler (knabbelschaar) to cut it
and don't cut to much at a time or you get blisters.
I made half a dozen of display stands that way, which makes them easier to use with breadboards.
This is an iphone stand from 2 pieces of PC case and some tape.
Its usefull with programming, as you can take the iphone out and its still connected with the
debugging Mac. In a normal dock you would have lost connection. I also made a taller one for an ereader.
Just a little jig i use to make connectors with headerpins for use on breadboards.
I use experiment board where 3 holes are connected, and solder header pins to that.
cd rom motors.
I got some motors from old CDrom drives, and wonderd if i could use them as a sort direct drive in a robot.
By just putting wheels on them, as they should have more torque as normal motors.
So i made some adaper cables for these flex cables from connector from old drives and printers.
I tried to use a motor by connecting them to 3 phases made with 6 transistors and a basic stamp and that seems to work.
I did not use the HAL sensors in the motor, but with low rpms and low acceleration it seems to work.
Also you could use the HAL sensors in the motor as some sort of position indicator, or use the cable with
other devices like displays from phones.
cd rom heads.
Way back in school i did some reports about how CDplayers work, and years later i opened up
some broken CDrom drives and wondered if i could use the heads to make something like a scanning microscope.
So i figured out the connections and made some adapter cables, and soldered some protection cables
to the laser connections. I made a little object table with the lens actuator from another CDrom head.
Also with these cables and the earlier CDrom motor cable it might be possible to control a complete
cd rom tray.
I was figuring to make servos from CDrom trays by adding a potmeter or some optical sensor.
so i can use them in a robot or scanner or plotter. With three of these connected to each other
it should be possible to move a device in 3D. You might not even need the potmeter but send
pulses with a specific lenght to the motors but you would have to go back to the start position
a lot to make sure the position is calibrated.
Little adapter to be able to program Scenix/Ubicom SX28 processors on a breadboard.
Using a parallax serial in circuit programmer.
scanning tunneling microscope.
I was thinking about making a scanning tunneling microscope, i took some heavy metal plates
which where supposed to hold the arms rests of a desk chair and connected them to some springs as a
base without vibrations.
Took some piezo buzzers and make some very fine scratches on them to divide them in 4 parts.
I glued a jumper to the piezo, so i can insert a tiny PCb with header pins as a scanner.
From some old HP printers i got a lot of tiny tiny springs that connected the heads to a board, which
might be fine to make connections to the piezo.
Now i need some mechanism to move the sample. I am thinking of the motor that moved a CDrom head.
To move the piezo i want to use an mbed that charges and discharges a capacitor to move it with steps,
and use the ADC of the mbed to check the actual position.
Still a big experiment.