KA7OEI built a battery pack to replace the obsolete “A/B” battery for Zenith TransOceanic (ZTO) H-500 and wrote a post on his blog detailing its assembly: There are several things that I decided that this voltage converter should do: Automatically power up and shut down when the radio is turned on and then off Cause […]
Category Archives: hacks
Qume 842 8″ floppy drive with a RC2014 Z80 retrocomputer
Dr. Scott Baker writes, “In this video, I try out some Qume 8 inch floppy drives that I bought on eBay. I interface them to a WD37C65 controller on my Z80 CP/M computer and I format the disks and read/write some files to them.” More details at Dr. Scott M. Baker’s blog.
LiPo batteries hacking and refurbishing
Karman wrote an article showing how to refurbish dead batteries to extend its life: One of the difficult parts when prototyping is to find reliable power sources. Today is still hard to find the battery size we want to use because country exporting frontiers stops these chemical packages. Here I’ll show how to refurbish dead batteries […]
A simple push-pull audio amplifier using russian rod tubes and power transformers
KA7OEI blogged about a simple push-pull audio amplifier using russian rod tubes and power transformers: Many years ago I’d read about the type of tube that is now often referred to as a “Gammatron” – a “gridless” amplifier tube of the 1920s, so-designed to get around patents that included what would seem to be fundamental aspects […]
Hacking your mouse for rapid firing
Kerry Wong has written an article detailing a simple hardware hack to make your mouse capable of doing rapid firing: In this blog post, I will show you a simple hardware hack to make your mouse capable of rapid firing (or automatic continuous clicking). Of course you can always resort to software mods to achieve […]
Nuclear physic applied in smoke detectors
Robert Gawron writes: Not many people know, but in some smoke detectors, radioactive materials play an essential role. Today I will present one of those devices, and my -successful- attempt to reverse engineer it and get the circuit diagram. Those smoke detectors uses a small amount of Americium-241 (chemical symbol: Am) obtained in nuclear reactors […]
Brute force computation for cheap log digital potentiometer
Michael from Acidbourbon writes: This article covers the attempt to build a digital logarithmic potentiometer out of two linear potentiometers. The benefits of this concept Linear digital potentiometers can be easily procured and don’t cost much There are IC packages with two or four modules inside anyway The resulting logarithmic potentiometer is very flexible in […]
Updating the KLN89B
Dmitry Grinberg writes, “Updating a 1996 plane GPS the 2016 way. Reverse engineering of old proprietary data cards, formats, binaries, creating of new tools to perform updates and their final open-source release.” More details at Dmitry Grinberg’s blog. Via the contact form.
Automatic volume tracking for a TV
An automatic volume tracker by KA7OEI: It occurred to me that I did have a reference on which I could base an outboard volume control: The internal speakers of the TV. I surmised that I could “listen” to the audio level coming out of the speakers and based on that, adjust the volume of an outboard amplifier. […]
RC2014/LL and RC2016/10
Scott Lawrence has written an article detailing his Z80 homebuilt computer, the RC2014: The RetroChallenge is upon us again! This time around, I plan on working on my Z80 homebuilt computer, the RC2014. (Website for RC2014, Order a RC2014) For a few months now, I’ve had my RC-2014 computer built, and modified to be an RC2014/LL […]
DIY USB power bank from laptop battery
A DIY USB power bank made from an old laptop battery from DoItYourselfGadgets: A situation many can relate to: an empty smartphone battery and no outlet around! That’s exactly why I recycled an old laptop battery into an USB power bank. This article will show you the basic powerbank circuit consisting of Lithium cell charging circuit, […]
A low-voltage disconnect for 12 volt lead acid and lithium batteries
KA7OEI writes: The avoidance of overcharging is usually pretty easy to avoid: Just use the appropriate charging system – but overdischarge is a bit more difficult, particularly if the battery packs in question don’t have a “protection board” with them. Lead acid batteries (almost) never come with any sort of over-discharge protection – one must […]
Hacking HAKKO 936
Simon Ludborzs writes: For many years I lived with dodgy epoxy fix on the handle, and finally swapped it out with a cheapie from eBay. All the HAKKO bits (tip, barrel, heating element) got transfered to the plastic handle and all was good in the world. Except for the heater LED. Like all Hakko’s the […]
Your laundry is done
Xose from Tinkerman has published a new project: I often forget my wet clothing in the washer and after a day they really smell… so I thought about monitoring my washer and get a notification in my phone when the laundry is done. An ESP8266 based Sonoff by ITead, current monitoring circuitry, a DHT22 (the washer […]
9V/1kV DC/DC converter
Robert Gawron’s home insect electrocution project: Currently I’m working on a device to electrocute home insects like cockroaches, progress is small because they are smarter than I thought, but that’s a different story. For that project I had to find a source of sufficient high voltage and output power. Presented in previous post 5V/400V converter […]
DIY smart glasses
Harris has been working on his DIY smart glasses: The glasses themselves are based around an STM32F051K8 microcontroller (LQFP32 for easy soldering!). All the firmware is custom written though I got the LCD driver initialization codes from the BuyDisplay examples. The firmware is written using a somewhat “co-operative scheduling” with interrupts methodology and for most […]
AUX in Volvo HU-XXXX radio
Karl Hagström wrote an article detailing how he hacked the stereo (HU-650) in his Volvo V70 (2007) and added his own AUX input: Why, why, why isn’t there an AUX input on my car stereo from 2007? Yes 2007 was before the big era of smartphones, but everyone owned a couple of dirt cheap mp3 players […]
Using Tronsmart Pavo M9 for HDMI input streaming
Danman wrote: Thanks to a tip of my reader, I found a relatively cheap (69Eur) Android box with HDMI input and record ability. I thought that it should be possible not only to record the HDMI input but also to stream it in realtime so I ordered one for experimenting. Full details at Danman’s blog.
Butchered USB TTL serial adaptor
Turning a USB to RS232 adaptor into a USB to TTL serial adaptor by Aaron Brady: I didn’t want to wait, so I had a look around what we had on hand. We did have a spare RS232 to USB adaptor. This one speaks the full ±15V, and I briefly considered using one of the spare […]
Hacking a UART where there never was before
Thanks to Andrew for sharing – check out the full post on their blog, MOAM Industries. As part of a prototype developed 12 months ago I was tasked with reading measurements from a blood pressure cuff [sphygmomanometer] in real time. Not surprisingly there are no consumer level devices that have a serial interface because what […]