Author Archives: DP

USB & Serial LCD backpack free PCB build

Microman171 built a free USB Universal LCD backpack PCB. This project interfaced a HD44780 compatible LCD via USB or serial connection. He would like expand the project to be a standalone temperature indicator with USB connectivity. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever […]

Re-purposing an LCD from a cheap picture-frame key chain

Here is a hack to extract, and use the LCD from a cheap picture-frame key chain. The project involved desoldering the LCD from its mainboard and building a breakout for it. With the help of a DSO it was possible to find out the pin-out for the LCD. The AVR library used to drive this […]

MSP430 online code editior, compiler, and programmer

Here is an online IDE for MSP430 microcontrollers. You can edit your code, compile, and program it, all online. All that is required is to sign in with a Google account. You edit C-code within your web browser without having to install an IDE such as IAR or CCS on your computer. The files are […]

LED covered ball with mic, Bluetooth, and an accelometer

Charlie built a ball covered with LEDs, unfortunately he didn’t leave much information about his project. What we do know is that it features a mic, Bluetooth, accelerometer to control the LEDs. It also has a built in rechargeable battery. We invite him to share more information about his project. Via the forum.

App note: General layout guidelines for RF and mixed-signal PCBs

Rsdio came across an interesting app note from Maxim and shared it with us. These are some PCB layout guidelines for RF and mixed-signal designs. This application note provides guidelines and suggestions for RF printed-circuit board (PCB) design and layout, including some discussion of mixed-signal applications, such as digital, analog, and RF components on the […]

App note: LM5022 DC/DC boost controller

Here is a part from National Semiconductor designed for controlling high-power DC/DC boost regulators. What makes it interesting is that its PWM frequency can be pushed to 2Mhz. This allows for smaller and cheaper discrete components, like inductors and capacitors. The datasheet on this device also provides some nice PCB guidelines to maximize its efficiency […]

App note: Thermocouple measurement

Last week we wrote about a Maxim app note about high precision temperature measurement with thermocouples. At Jim’s request we found a more in-depth intro to thermocouples. This app note from Linear Technology covers everything you ever needed to know about thermocouples. Learn how thermocouples were discovered, and how to build very elaborate and highly […]

Cadsoft Eagle review by a new user

Pete decided to try out Cadsoft Eagle and write about his experience. The first impression wasn’t the best. I finally decided to download and learn to use the industry-standard PCB and schematic layout software: Eagle. I’ve tried a bunch of others, and quite frankly, got tired of always using “also ran” software. The majority of […]

Using a ACS712 hall-effect current sensor

Raj made a two part tutorial on how to interface a PIC microcontroller with the ACS712 hall-effect current sensor. The first part covers hall-effect theory and basic operation of the ACS712. The second part covers the actual PIC interface, which is simply reading the output voltage of the sensor. Sensing and controlling current flow is […]

Week in (p)review: January 27, 2012

Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon: Workshop video: USB Persistence of Vision Toy firmware Programmable dummy load in this week’s status update post Dangerous Prototypes 3D project models CPLD breakout board ported to KiCad Bus Pirate mentioned in Bruce Perens open hardware lecture C […]

2012 Digilent design contest with FPGA and PICs

Diligent has announced its 8th annual design contest. Student are invited build electronics projects based on their FPGA and PIC development boards. So far the contest has been announced in the US and EU. Unfortunately the EU region registrations are over. The entrants will receive Diligent development systems pertaining to their project needs, which they […]

Open source USB stack for PIC18F and PIC24F updated

JTR released a major updated to the open source USB stack that’s been brewing in the forum. It’s been designed to work with a generic echo demo, the Bus Pirate v4, the USB IR toy, the LCD Backpack, the Locgic Shrimp, and the Logic Sniffer. So far only the CDC class is supported, meaning only […]

Control your garage door via WiFi interface

This WiFi garage door controller is based on an RN-XV WiFi module, a small WiFi capable microcontroller with 8 GPIOs, and 3 ADCs. The inspiration for this project was simple. My daughter has a habit of forgetting her house key, and we’ve had mixed results with the wireless garage door opener keypad. Time for a […]

Bus Pirate mentioned in Bruce Perens open hardware lecture

Bruce Perens, the author of the Open Source Definition, and co-founder of the Open Source Initiative,  held a lecture on the topic of “The State Of Open Source, And Introducing Open Hardware”. He mentions the Bus Pirate and our CPLD breakouts as positive examples of open hardware. The Gadget Factory’s Papilio One FPGA development board […]

C library for the Bus Pirate binary scripting mode

Bquoitin developed a C library for interfacing with the Bus Pirate binary scripting mode. So far he has successfully used it to communicate with various SPI devices: “libbuspirate” [is] a short C library that allows easy interaction with the Bus Pirate. It was written a few months ago and I’ve been using it several times […]

FIRST DRAFT: Programmable dummy load

  This is a programmable current sink, usually used to simulate  different current loads for power supplies. We have always wanted to build one, but we’ve stalled several times. This design is based on the simple analog load posted by Bearmos. It’s not intended to be a final project, it’s just an experimental prototype to […]