Author Archives: DP

App note: Current sense circuit collection

Here’s a current sense circuit collection from Linear Technology. The collection is organized by application type and for each one there are a few example circuits. High side, low side, level shifting, high and low voltage, fault sensing, etc: Sensing and/or controlling current flow is a fundamental requirement in many electronics systems, and the techniques […]

App note: PCB layout tricks, striped capacitors, and more

While it doesn’t matter what direction non-polarized capacitors are soldered into a circuit, some feature a stripe indicating which contact is connected to the outer shell of the capacitor. The article describes how to best take advantage of this in your designs. The outside foil of a spiral-wrapped film capacitor shields the inner conductor. In […]

App note: Using USB flash drives with USB host capable PICs

Here’s an app note from Microchip describing how to use USB flash devices with microcontrollers that have USB host capability. The article also provides instructions on how to use the USB OTG Configuration tool. This document describes the USB Data Logger, Mass Storage demo application. It gives an overview of the application’s firmware, how it […]

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 […]

Week in (p)review January 11, 2013

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. WORKSHOP VIDEO #51: Fake flash drive, QFP protoboards, 1 year of workshop video retrospective New QFP prototyping boards tests arrived ATX Breakout Board V1.1 Acrylic case V1 back in stock at Seeed MMA7455L accelerometer and ENC424J600 breakout free […]

Workshop Update for January 10th 2013

We cleaned up the old Bus Pirate SVN repository, and left pointers to the new firmware source in the Dangerous Prototypes repository. This should prevent some confusion. We finished up today and next weeks videos, and got interviewed by EEWeb. We’re working to implement control over the pull up voltages in Bus Pirate v4’s binary […]

Dual motor driver LaunchPad booster pack

Parker designed a dual motor driver booster pack for the MSP430 LaunchPad. It’s based around the DRV8833 iterated motor driver capable of controlling voltages up to 10.8V and handling current up to 2A. You can download the Eagle source files from his site. This is a Low Voltage, 2A motor controller BoosterPack for the Ti […]

WORKSHOP VIDEO #51: Fake flash drive, QFP protoboards, 1 year of workshop video retrospective

Teardown of a fake USB flash drive from India and a USB charger from China. A look at the new xQFP protoboard v2 PCB, and a new filing system for free PCBs. We’ve been doing workshop videos for more than a year now, so we look back on the evolution of the weekly updates. While […]

Raspberry Pi sandwich plate inspired by Sick of Beige

Boisblas tweeted a picture of his Raspberry Pi setup, inspired by our Sick of Beige case. The Pi is mounted on a plastic plate with hex standoffs. Like our cases it’s not fully enclosed, but it does provide some protection from those pesky shorts when the board is placed on conductive materials. Raspi sandwitch plate […]

MMA7455L accelerometer free PCB build

Dmmedia built a free MMA7455L accelerometer breakout board. The MMA7455L is a 3-axis accelerometer with I2C and SPI interfaces. 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 the MMA7455L breakout […]

Workshop Update for January 9th, 2013

Today we worked on implementing patches to the Bus Pirate that Mrmr was kind enough to contribute in the forum. The two patches fix some issues we had with the frequency measurement function of the Bus Pirate. The first patch fixes our long integer to string conversion function which added ‘0’ where it shouldn’t have. […]

8 digit 7 segment display with SPI interface

Raj designed this 8 digit 7 segment display with an SPI interface using a MAX7219 display driver: The SPI7SEGDISP8.56 module can be interfaced with any microcontroller that has 3 I/O pins available. If the microcontroller features a built-in hardware SPI, then the display module can be interfaced as a SPI slave device. In that case […]

TI launches real-time operating system

Texas Instruments has released a free real-time operating system (TI-RTOS) designed for their microcontroller range. They implemented TCP/IP and USB stacks, a FAT file system, and some device drivers. The TI-RTOS’s source code is released under a license that allows you to use their code as long as you use it on their devices and […]

New QFP prototyping boards tests arrived

A box of PCBs just arrived from Seeed Studio’s Fusion PCB service, expect them soon in our free PCB drawer. This batch includes: xQFP80 +65 Protoboard xQFP80 +50 Protoboard xQFP50 +65 Protoboard They are the latest revision of the QFP protoboards already available at Seeed. Here’s the change list  (QFP protoboard 0.80mm + 0.50mm v2) […]