Recent posts

PWM Based LED Driver

A followup to the constant current driver for a high power LED post, Elmars writes: If anybody is interesed, I have posed a follow up to this original post with a simple PWM LED driver, adding an ATtiny85 mCU. The post includes schematic, board...
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Inside the Intel 1405: die photos of a shift register memory from 1970

Ken writes: In the Datapoint 2200, each memory board had 32 shift registers, providing 2K of storage. The processor board used a counter to keep track of the shift register position, and would stop processing until the right bits were available....
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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...
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App note: Design considerations for single-sided sensing applications of reflective assemblies

App note from TT Electronics on reflective assemblies and the surfaces they need to effectively detect/sense. A reflective sensor provides a major mounting advantage to the designer because only one side of a sensing surface is required. However,...
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App note: Designing encoder elements for two channel optical interrupters

An app note from TT Electronics on design and getting information out of encoder elements of two channel optical interrupters. Rotational direction of a shaft can be readily determined by utilizing the two channels of a dual optical interrupter,...
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App note: Introduction to USB Power delivery applications

Another application note from Microchip, an introduction to USB Power delivery applications (PDF!): This document is designed for systems and hardware engineers seeking the information necessary to begin to integrating USB Power Delivery (under...
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App note: Microchip dedicated slave devices in I2C systems

An app note on Microchip dedicated slave devices in I2C systems (PDF!): Microchip supplies dedicated slave devices that include a two-wire serial interface that is System Management Bus (SMBus) and I2C™ compatible. The SMBus specification is...
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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 two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget...
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PCB for Raspberry Pi WH1080 weather station

A PCB for Raspberry Pi WH1080 weather station by Andy Ayre of BritishIdeas: Previously I wrote about using a Raspberry Pi to receive 433MHz signals from a WH1080 weather station. This is the mess of wiring I came up with. This worked fine until...
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Eagle vs. KiCad revisited

Steve Chamberlin of Big Mess o’ Wires writes: Four and a half years ago, I wrote a mini-review of Eagle vs. KiCad, two of the most popular software tools for hobbyists creating custom circuit boards. I concluded that while KiCad had lots of...
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