Author Archives: DP

App note: Class D Audio Amplifier Basics

A good read about class D Audio Amplifier, an app note from International Rectifier A Class D audio amplifier is basically a switching amplifier or PWM amplifier. There are a number of different classes of amplifiers. This application note takes a look at the definitions for the main classifications.

App note: High resolution RGB LED color mixing

This application note from Microchip demonstrates color mixing using the PIC12F1572 MCU (PDF!): This application note demonstrates color mixing using the PIC12F1572 processor. The PIC12F1572 processor features three 16-bit pulse-width modulators (PWMs), among other peripherals. The 16-bit PWMs allow precise control over each RGB LED, allowing smooth transitions even at low-brightness/luminosity levels.

App note: Enable automotive USB power – Managing the increasing currents, longer cables, and tight portable-device specifications

Here’s an application note from Maxim:  Enable automotive USB power – Managing the increasing currents, longer cables, and tight portable-device specifications This application note discusses the challenges of rapid USB charging of today’s portable devices (PDs) in an automobile. The PDs may not charge quickly or charge at all, especially the more recent power-hungry devices. […]

Pushing VLAN tags through unmanaged switches

Kenneth Finnegan writes: This year, I was designated as the computer network zonie, so it’s my job to make sure that there’s IP connectivity between all the major sites in the network. This involves building a computer network that includes a couple Internet hand-off points, multiple routers, several medium-range (2-5km) microwave links, QoS enforcement for […]

New Energia version available

The Energia team announces the availability of version 0101E0012.  We wrote about it previously: Energia is an open-source electronics prototyping platform started by Robert Wessels in January of 2012 with the goal to bring the Wiring and Arduino framework to the Texas Instruments MSP430 based LaunchPad. Energia uses the mspgcc compiler by Peter Bigot and […]

HP LaserJet 4000 front panel with Bus Pirate

kbiva has posted a detailed tutorial on how to connect and control HP LaserJet 4000 front panel with Bus Pirate v3.6: Connected 7 lines from printer front panel to corresponding Bus Pirate pins. SPI parameters set in Bus Pirate: -SPI speed is 1Mhz -Clock polarity: Idle low -Output clock edge: Active to idle -Input sample […]

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 […]

Meet the amazing China power outlet

By ian Traveling abroad you’ll likely encounter many different outlets. While most of our stuff uses an adapter that will take any local power supply from 100volts to 240volts, the plug shapes are still different. Usually you buy a way over-priced adapter for a specific region before heading out. Not in China! In Shenzhen most […]

Week in (p)review March 21, 2014

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. Hacker Camp Shenzhen – Shenzhen workshop hackerspace passport stamps Bus Pirate v3.6, Logic Sniffer are back in stock Bus Pirate v3.8 free PCB build NXP ARM Cortex M0/M3 LQFP-48 Breakout board free PCB build and a swag bag revival Check out […]

BJT in reverse avalanche mode

Kerry Wong writes: Transistors operating in their avalanche regions are often used to generate fast rise pulses (see avalanche pulse generator using 2N3904). Many transistors can also avalanche when the connections to collector and emitter are reversed. When operating in reverse avalanche region, these transistors are sometimes referred to as negistors. Because the asymmetry and […]

µ-Wire: USB on ATtiny10 controlling a WS2812 LED

cpldcpu writes: I tried to push the ATtiny10 to its limits and succeeded – I implemented a seriously gutted version of V-USB on an SOT23 ATtiny10 with just 1kb flash and 32b of RAM. It implements a subset of the little-wire protocol to control a single WS2812 LED. I am currently also working on size […]

Shenzhen workshop hackerspace passport stamps

By ian Everyone attending Hacker Camp Shenzhen will get a Chinese-style hackerspace passport made by Seeed Studio. We created two stamps for the camp. One is for the market tour, the other for the soldering workshop. Hold onto the passports, there will be many more opportunities to get stamps at the Shenzhen Maker Faire following […]

Piezoelectric crystal speaker build

This video by RimstarOrg demonstrates how to build a Piezoelectric crystal speaker: I make a loud speaker for a clock radio using a piezoelectric crystal. Actually I experiment with a variety of piezo crystals. That includes a piezoelectric igniter crystal from a BBQ lighter and a homemade/DIY rochelle salt piezoelectric crystal. I also try out a piezo buzzer from […]

DIY digital desk clock with temperature display -part 1

A digital desk clock with temperature display feature by Electro-Labs: The brain of the circuit is a Microchip PIC18F252 microcontroller. It acquires precise time information from DS1307 real time clock via I2C interface and displays it on four digit 38 mm seven-segment display with the help of MAX7219CNG display driver. The temperature data is read […]

Hacked GTP USB LITE pic programmer

cmardone of Valpoder wrote an article on hacking the GTP USB LITE usb pic programmer, we wrote about it previously: GTP USB LITE is a pic programmer based on the pic18F2550 disgned by SISPIC from spain A lot of people built this circuit , and it became obsolete.. The firmware has several limitations(ex: driver only for xp) […]