An old but interesting app note(PDF) from Microsemi on resistorless current-sensing technique. This application note introduces a simple current-sense technique that eliminates that sense resistor, resulting in system-cost reduction, PCB space saving, and power efficiency improvement. Furthermore, the new current sensing mechanism allows higher dynamic tripping current than the static one (built-in low-pass filtering) to […]
Author Archives: DP
App note: Magnetoresistive angle measurement
An angle measurement solution from Analog Devices app note (PDF!). An AMR (anisotropicmagneto resistive) angle measurement solution with 1°angular accuracy over a 180° range. The circuit is ideal for applications where high speed, accurate, non-contact angle measurements are critical. The circuit provides all necessary signal conditioning including instrumentation amplifiers, buffers, and a dual channel ADC […]
Using the AVR hardware multiplier
Here’s how to use the hardware multiplier to make a multiply-and-accumulate operation (MAC), an app note from Atmel (PDF!): Features • 8- and 16-bit Implementations • Signed and Unsigned Routines • Fractional Signed and Unsigned Multiply • Executable Example Programs The megaAVR is a series of new devices in the AVR RISC Microcontroller family that includes, among other […]
A single-supply Op-Amp circuit collection
An application note from Texas Instruments, A single-supply Op-Amp circuit collection (PDF!): There have been many excellent collections of op-amp circuits in the past, but all of them focus exclusively on split-supply circuits. Many times, the designer who has to operate a circuit from a single supply does not know how to do the conversion. Single-supply […]
Single chip AVR BASIC computer
Dan over at HackAday documented his single chip computer project with the PCBs from DirtyPCBs: A single AVR microcontroller (the ATmega 1284P) has been used to create a standalone computer system which runs the BASIC programming language. The 1284P runs TinyBASIC Plus, generates RCA video signals (using TVout) and reads PS/2 keyboard input. A single sided […]
Bus Pirate v3.6 Sick of Beige v1 acrylic case v1 back in stock
Bus Pirate v3.6 Sick of Beige acrylic case v1 is back in stock at Seeed Studio. Version 1 of the basic case is simple, cheap, easy to assemble, and fits our Sick of Beige standard PCB sizes. Check out our tutorial on how to customize Sick of Beige cases. Get Bus Pirate v3.6 acrylic case […]
Powerpole fused distribution board
Brian Dorey writes: We use Anderson Powerpole connectors on our ham radios and other 12 volt accessories in the house and we had always used leaded plugs connecting to a central point with inline fuses on each one. There are commercial Powerpole distribution boxes available but they are very expensive and difficult to obtain in the […]
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. More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week: Free PCB Sunday. The classic. Every week, get […]
SmartMatrix project
Pup05 shared his SmartMatrix project in the forum. He writes: The panel fits perfectly, just had to shim it with a little bit of folded card stock on each side. There’s plenty of room for the Teensy and SmartMatrix board, wiring, SD card, etc. I cut out a piece of white printer paper to size, and placed […]
Week in (p)review July 11, 2014
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. Bus Pirate v3.8 free PCB build Yet another Logic Sniffer case Bus Pirate v4 talks I2C to TI Fuel Gauge FT2232H breakout board is back in stock Coming up: Free PCBs via Facebook on Friday App notes […]
Open source Android thermostat project
Android Thermostat, an open source DIY home thermostat project based on Android: Android Thermostat is an open source thermostat project ideal for programmers and electronics hobbyists. As the name suggests the application runs on Android phone that is connected to some basic electronic components for controlling your home HVAC system.It costs around $140 to build […]
Building a Strata 1 NTP server
Kenneth Finnegan writes: As a quick first test, I built a quick adapter board between the GPS engine’s 2×5 pin header to the standard FTDI serial cable, with a diode and 0.3F capacitor (Yes, not micro Farads, 0.3 actual Farads) to keep the SRAM from losing the current GPS almanac every time I power cycle […]
FT2232H breakout board back in stock
The FT2232H USB 2.0 Hi-Speed breakout board is back in stock at Seeed Studio. This is a breakout with a FT2232H high-speed dual-channel USB-to-serial chip that has two JTAG debug channels. Get one for $27.
Constant Current Electronic load
Juan of ssihla build this DIY electronic load. He writes: The design is based on some of the various diy electronics loads out there (like the one from Dave Jones). The mosfet is a P45N03LT , most likely I took it from some of the PC power supply I’ve “recycled”. I’m using two 25k potentiometers, one for […]
Nixie tube clock
Tom Cousins of DOAYEE made this DIY nixie tube clock: Below is the schematic for the project, as you can see I’m using 6 IN12 nixie tubes, each with it’s own 74141 nixie tube driver. These drivers are great! They simply connect directly to the nixies and display whatever 4 bit binary number you give them […]
Pick and Place controller v3 part 2
An update on Brian’s Pick and Place controller v3: Following from the previous Pick and Place Controller V3 Part 1 post we have now built and installed the new control board for the pick and place machine. While building and testing the board we found an issue with one of the pins on the main microcontroller […]
Mini LED volume towers (VU meters)
Here’s a cool Mini LED volume towers project by Ben Finio. He writes a complete step-by-step instructions here: The inspiration for this project started when I saw a variety of awesome stereo LED towers on YouTube (also referred to as VU meters). Many of the videos showed the end result, and maybe a slideshow of the […]
Bus Pirate v4 talks I2C to TI Fuel Gauge, Papilio Pro as logic analyzer
A video on using Bus Pirate v4 to talk to a TI bq27510 Fuel Gauge by pitface123: The Fuel Gauge is mounted on the Fuel Tank Booster Pack. A Papilio Pro that is programmed as Logic Sniffer is used as the Logic Analyzer and protocol analyzer. Nifty prototyping platform. JaWi’s OpenLogic Sniffer as Logic Analyzer […]
OLED watch is alive!
Jared Sanson posted an update on his OLED watch. He writes: Here’s a few features of my firmware: USB HID Communication (No PC drivers required!) Watch face for telling the time (Kind of required…) Date & Upcoming events Accelerometer reading RTOS Kernel debug info And some features planned for the future: Bluetooth 4.0 (Still need to […]
Yet another Logic Sniffer case
@0x2B2B tweeted, “Case for my OLS, laser cut at @RazorLAB. Design file in post 2byt, make your own! Why the case? Well, being the fan of OSS/OSH (that’s; Open Source Hardware :) that I am, this was a nice, affordable entry into the market of Logic Analysers. It’s always great having bare P.C.B.s because come […]