David built a free Bus Pirate v3.8 PCB. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever – we’ll send you a coupon code for the free PCB drawer. Get your […]
Author Archives: DP
#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 […]
ESP8266 mains energy monitor
A ESP8266 mains energy monitor project by Brian Dorey: As the new solar logger did not have this functionality we decided to design a new data-logger that would measure not only the mains current usage but also keep track of the electric meter and gas meter so we can easily see how much energy we […]
Freescale’s sensors breakout boards
Freescale’s sensors breakout boards from Juan Ignacio Cerrudo: MMA8541Q, FXOS8700CQ, MPL3115A2 and Logic Level Converter: The MMA8451Q is a low-power, three-axis accelerometer with 14 bits of resolution. It communicates over I2C, has built in tilt/orientation detection and also tap detection. More details at ssihla site.
MIDI to USB adapter with Teensy LC
Joonas has written up documentation on his MIDI to USB adapter with Teensy LC: Thankfully, I had a MIDI connector and a high-speed optocoupler at hand, and with these I could implement a MIDI in rather easily. After some investigation with Arduino Uno, it seemed quite simple to receive the serial MIDI bytes and dump them […]
App note: PointLED® – It’s nice to be different
New SMD LED design from OSRAM ideal for mounting on PCB holes for illumination. Link here (PDF) This application note provides insight into the universally deployable and flexibly mountable light source of the PointLED® product family. A fundamental overview of the LED construction as well as the optical and electrical characteristics and performance of the […]
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: How to handle a reed switch
Proper handling of reed switches to prolong operation and or storage, an application note from HSI sensing. Link here (PDF) Reed switches consist of two or three metal reed contacts (blades) that are hermetically sealed inside a glass tube. This seal, while strong, may be damaged if proper handling is not used. HSI Sensing has […]
App note: AES Bootloader
An application note (PDF!) from Atmel on AES Bootloader: This application note has presented a method for transferring data securely to an Atmel AVR microcontroller with bootloader capabilities. This document has also highlighted techniques that should be implemented when building a secured system.
More ARM1 processor reverse engineering: the priority encoder
In a previous post, Ken Shirriff reverse engineered the silicon in the ARM1 processor, this time he reverse-engineer the priority encoder in the ARM1 processor: In this article, I reverse-engineer the priority encoder in the ARM1 processor. By examining the chip layout provided by the Visual ARM1 project, I have determined how this circuit works […]
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 […]
Using a $2 DS3231 RTC & AT24C32 EEprom from eBay
From the comments on our ‘Using DS1307 and DS3231 real-time clock modules with Arduino‘ post, Edward Mallon writes: I’ve been putting the $1 DS3231 boards through their paces for quite a while now…and they have been performing well. More details at Edward Mallon’s blog. Via the comments.
RF probe
m0xpd writes: Today I finally got round to building a nice little RF probe kit from Rex, w1rex, the Tuna King over at QRPme. I took the well-executed PCB which – unusually for Rex – had through hole mounting for the components rather than the ‘Limerick’ construction that recently I’ve come to associate with him… Following […]
Fobble, a general purpose wireless breakout board
Ken Boak has been working on a general purpose wireless breakout board – Fobble: As can be seen from the above picture it contains a number of key features: A resident RFduino Bluetooth Low Energy Module with ARM Cortex M0 processor 2 layer pcb 50 x 50 mm format- with extended Arduino headers pin-out An X-Bee footprint […]
Counting bits in hardware: Reverse engineering the silicon in the ARM1 processor
Ken Shirriff writes: How can you count bits in hardware? In this article, I reverse-engineer the circuit used by the ARM1 processor to count the number of set bits in a 16-bit field, showing how individual transistors form multiplexers, which are combined into adders, and finally form the bit counter. The ARM1 is the ancestor […]
Mullard 3-3 amplifier project (part 1)
Dilshan Jayakody has published a new build, a Mullard 3-3 amplifier project: Mullard 3-3 is quiet popular 3W tube amplifier introduced by Mullard Ltd in 1956. A schematic and design detail of this amplifier is available in “Mullard Circuits for Audio Amplifiers” book and in National Valve Museum article. This amplifier is based on EF86, EL84 vacuum […]
Building a tracking generator
A how-to on building a tracking generator using off-the-shelf components by Kerry Wong: In this blog post, I will show you how to build a 0 to 5.8 GHz tracking generator for the HP 8566B 100 Hz to 22 GHz spectrum analyzer using off-the-shelf components for under $100. Although this tracking generator is specifically designed for […]
#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 […]
Monitoring woodstove temperature with a MAX31855 Quad Thermocouple BoosterPack
Spirilis over at the 43oh forum writes: This was a project begun last winter in the hopes of having an array of thermocouples to monitor my old woodstove when operating it. Well, I never got around to finishing it, but I have a fancy new woodstove as of this fall, and I would love to monitor its […]
FLIR MR160 thermal imaging and moisture meter review, teardown and experiments
Another great video review from TheSignalPath: FLIR MR160 Thermal imaging and moisture meter review, teardown & experiments In this episode Shahriar takes a close look at the FLIR MR160 Thermal Imaging and Moisture Meter. Featuring Infrared Guided Measurement (IGM) technology powered by a FLIR Lepton® thermal imaging sensor, MR160 helps you quickly see temperature patterns that […]