Boris Landoni from Open Electronics writes about a new open source Demoboard MP3 audio player DFR0299: Let’s test out the capabilities of the DFR0299 audio player module, an ideal choice for Arduino but also for many stand-alone applications. In this article, we decided to design and propose a demoboard for the DFR0299 module we already […]
Author Archives: DP
Analyzing the vintage 8008 processor from die photos: its unusual counters
Ken Shirriff writes: The revolutionary Intel 8008 microprocessor is 45 years old today (March 13, 2017), so I figured it’s time for a blog post on reverse-engineering its internal circuits. One of the interesting things about old computers is how they implemented things in unexpected ways, and the 8008 is no exception. Compared to modern […]
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
A Solid State QRP Rig from 1955!
Pete Juliano, N6QW, built his own vintage 1955 Solid State QRP Transmitter using the Philco SB-100: Recently my friend Bill, N2CQR posted data on his blog ~ soldersmoke.blogspot.com about a vintage late 1950’s early 1960’s 10 milliwatt 10 Meter transmitter. That was quite a feat! But given my Italian heritage I could not let that […]
Bus Pirate v3.8 free PCB build
@kevinneubauer tweeted picture of his free Bus Pirate v3.8 PCB build. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff. 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 […]
Analog Discovery USB isolation
Bob writes: Back when I was deverloping the PSU burner, I wanted to have the Analog Discovery isolated from the common ground, to avoid noise and other issues. Since I did not have a way to do this, I ended up using a laptop on battery for measurements. But for long term, I needed […]
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 board service. This week two random commenters will […]
App note: Selecting coupled inductors for SEPIC applications
Application example from Coilcraft on how coupled inductors gain advantage over separately wound inductors, calculations included. Link here (PDF) The SEPIC (Single-Ended Primary Inductance Converter) topology is used in applications that require characteristics of both a buck and a boost regulator, specifically the ability to step up and step down the input voltage. Most often […]
App note: Choosing inductors for energy efficient power applications
Designing efficient power converters guide from Coilcraft. Link here (PDF) In high frequency DC-DC converters, inductors filter out the AC ripple current superimposed on the DC output. Whether the converter steps the voltage down – buck – or steps the voltage up – boost – or both up and down – SEPIC, the inductor smooths […]
Teardown and review of the new MHS5200A
Craig writes: I’ve gotten a lot of questions on the blog about the new version of the MHS5200A function generators available on eBay. Viewer Tolga was kind enough to send one in to me to review and tear down. Although some improvements have been made over the older models, there are some concerning issues with […]
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. The coupon code usually go to Facebook ‘Other’ Messages Folder . More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three […]
Hacking the DPS5005
Johan Kanflo’s OpenDPS project, a free firmware replacement for the DPS5005: This write up of the OpenDPS project is divided into three parts. Part one (this one) covers reverse engineering the stock firmware and could be of interest for those looking at reverse engineering STM32 devices in general. Part two covers the design of OpenDPS, […]
Cheep Mod II – a low cost platform for Euro-Rack digital audio
Eric Brombaugh writes, “This is a small 6HP Euro-Rack format module with 3 CV inputs, 3 pots, Digital (Sync) input, 16-bit stereo audio outputs. It’s a slight modification of the Cheep Mod I did earlier, but with a slightly more advanced MCU that provides I2S output and has more on-chip flash. One of the goals […]
Esp8266 WebServer farm
An Esp8266 WebServer farm project by Eldon Brown’s (a.k.a WA0UWH) After several long months, I have reactivated my Esp8266 WebServer Farm. Currently, one of my WebServers can be accessed as: esp.wa0uwh.com:8154 More info at WA0UWH homepage.
Temperature controlled etching bath with magnetic stirrer
Michael writes, “Yet another temperature controlled etching bath for producing PCBs at home. But this one has a magnetic stirrer :) Check out the video after the break. Project info at acidbourbon’s blog. Via the contact form.
#FreePCB via Twitter to 2 random RTs
Every Tuesday we give away two coupons for the free PCB drawer via Twitter. This post was announced on Twitter, and in 24 hours we’ll send coupon codes to two random retweeters. Don’t forget there’s free PCBs three times a every week: Hate Twitter and Facebook? Free PCB Sunday is the classic PCB giveaway. Catch […]
Datum/Symmetricom 8040 Rubidium frequency standard teardown
Teardown: A look at the Datum/Symmetricom 8040 Rubidium frequency standard The 8040 used an LPRO 101 (low profile Rubidium oscillator) oscillator. Interestingly, there is a note written on the top of the LPRO case: “vibration test may have magnetized cover”. As you may know, Rubidium standards’s accuracy is very sensitive to external magnetic field. But […]
Tiny ESP8266 Breakout Board
Stavros made a very small ESP8266 breakout board: A very small breakout for the ESP8266. Includes all necessary pullups/pulldowns for it to boot to your code, a LDO regulator, a 3V3 output pin and enough breadboard space for one row on each side on a standard breadboard. Full details on Github. Boards DirtyPCB order link here.
Keysight MXA revision-b signal analyzer / Spectrum analyzer review, analysis & experiments
Keysight MXA revision-b signal analyzer / Spectrum analyzer review, analysis & experiments from The Signal Path: In this episode Shahriar reviews the long awaited Keysight MXA Signal Analyzer (N9020B). The new X-Series Spectrum Analyzers from Keysight offer an entirely re-designed GUI interface which supports multiple tabs as well as multi-touch interaction. Check out the video after […]
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 board service. This week two random commenters will […]