Dave Curran has a nice build log on his ZX80 clone, which he call Minstrel: Here is a new ZX80 clone that I have called the Minstrel. It is a fairly accurate clone electrically to the ZX80, using the same chips and the original schematic with only a few concessions to the modern world. All the parts are the […]
Author Archives: DP
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 […]
Solar battery charge controller teardown
A teardown video of a solar battery charge controller from Electronupdate: A solar battery charger: one side goes to a Solar Panel, the other to a lead-acid battery. A charge controller allows the battery to be safely charged. Snagged off of Amazon. Seemed really cheap at $17.36. A look at the assembly quality tells me […]
App note: Add a “Black Box” fault logger to your “Big (or Small) Box” system
Application notes from Maxim Integrated on adding log functionalities in your system. Link here (PDF) This article describes how to add a “black box” functionality – nonvolatile fault logging – to networking, communications, industrial, and medical equipment. It outlines the benefits of recording fault data, including faster, more definitive failure analysis.
Free PCB Sunday: Pick your PCB
We go through a lot of prototype PCBs, and end up with lots of extras that we’ll never use. Every Sunday we give away a few PCBs from one of our past or future projects, or a related prototype. Our PCBs are made through Seeed Studio’s Fusion board service. This week two random commenters will […]
App note: Selecting current sensors and transformers
Selection guidelines from Coilcraft. Link here (PDF) Current sensors detect the flow of AC or DC current in a wire or circuit trace. They can be used to detect an on/off/ pulse current condition or to measure the magnitude of the current in the wire or trace. This discussion is limited to AC current sensors. […]
Happy New Year 2017 from Dangerous Prototypes
Happy New Year! Thank you for reading the blog and being part of our community in 2016! We’re looking forward to more open hardware projects, more how-tos, more videos, more free PCBs, and more hacking in 2017.
App note: Bluetooth low energy digital pedometer demo design
An application note (PDF!) from Microchip: A Bluetooth low energy digital pedometer demo design A digital pedometer is a portable electronic device that counts each step a person takes by detecting the motion of the person’s body with an accelerometer. This application note demonstrates the implementation of a Bluetooth Low Energy Digital Pedometer using the Microchip PIC16LF1718, […]
App note: IR remote control transmitter
IR remote control transmitter application note (PDF!) from Microchip: This application note illustrates the use of the PIC10F206 to implement a two-button infrared remote controller. The PIC10F2XX family of microcontrollers is currently the smallest in the world, and their compact sizes and low cost make them preferable for small applications such as this one. Two […]
A high-resolution sensor node
A high-resolution sensor node from JeeLabs: The JeeNode Zero is intended as sensor node in a Wireless Sensor Network. This requires: a sensor we can read out periodically, such as the BME280 being able to sleep with a very low current, as recently described the ability to run the node unattended, i.e. without FTDI cable […]
Free PCB coupon via Facebook to 2 random commenters
Every Friday we give away some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
Die photos and analysis of the revolutionary 8008 microprocessor, 45 years old
Ken Shirriff has written an article detailing die photos of the vintage Intel 8008 that reveal the circuitry it used: Intel’s groundbreaking 8008 microprocessor was first produced 45 years ago.1 This chip, Intel’s first 8-bit microprocessor, is the ancestor of the x86 processor family that you may be using right now. I couldn’t find good […]
Radioactivity detection using very simple ionization chamber and a single J-FET transistor
Robert Gawron writes: Today I will show a very simple ionization chamber that can detect radioactivity. I was able to detect with it ionizing radiation from a smoke detector (Am241 isotope). It’s also immune to electromagnetic interference (EMI) due to a good shielding. This device doesn’t explicitly use any power supply. It’s connected to a […]
Comfort Thermometer display built with 517 individual LEDs
Richard wrote in to tell us about a ‘Comfort Thermometer display built with 517 LEDs’ that he has just finished building: Comfort Thermometer Display built with 517 individual LEDs and the following microprocessors: 1) PiC24FV16KA301 – controlling outer 36 RGB LEDs 2) PIC16F886 – bargraph and pink LEDs animations 3) ATmega328 – controlling 7-segment display […]
DIY IKEA wireless Qi charging for the Hexiwear
Erich Styger built a DIY a wireless charging system for the Hexiwear: The Achilles Heel of the Mikroelektronika Hexiwear is its charging: the charging and USB connector are only designed for a limited number of plug-unplug cycles, and it does not have a wireless charging capability like the Apple iWatch. Until now! I have built […]
DirtyPCB X-mas tree
Matthias created a X-Mas tree project using the DirtyPCB boards: The project features an USB capable PIC16F1549 µC with: USB FS device 48 MHz internal Oscillator 2 PWM modules 10-bit ADC with Voltage Reference Integrated Temperature Indicator Module The LEDs are connected to the 2 PWM outputs via N-mos drivers. A Potentiometer is connected to […]
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 […]
Homebrew 40dB step attenuator
flathagen blogged about his step attenuator build: A home lab needs a step attenuator. It helps in evaluating RF amplifiers, filters and receivers. Both the legendary EMRFD-book, the ARRL handbook, and a variety of QST-articles provides circuit examples for building a homebrew device. Most of them follow the design principles from the January 1967 edition […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Mastr III repeater teardown
Kenneth Finnegan writes, “I recently purchased a pallet (!) of Mastr III repeaters for some parts. These are really unique radio systems since their so modular, so I thought you’d enjoy a video where I tear one apart and talk through its basic theory of operation.” More details at Kenneth’s blog.