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 […]
Author Archives: DP
Teardown of an HP 8671A microwave frequency synthesizer
Kerry Wong did a teardown of an HP 8671A microwave frequency synthesizer: I recently bought an HP 8671A microwave frequency synthesizer on eBay. This synthesizer can generate signals from 2GHz to 6.2GHz with an unleveled output of more than 8dBm. It is a nice complement to my HP 8642B signal generator and Wavetek 907 signal […]
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: Understanding infrared diode power ratings
App note from TT Electronics about infrared diode specs, how they vary from different manufacturers, and help clear things about infrared definition of parameters. Link here (PDF) Infrared emitting diode power measurement is dependent upon a number of variables which must be precisely defined in order for design engineers to utilize data sheet information. Manufacturers […]
App note: Linear and rotary encoders are evolving to meet demands
Application notes from TT Electronics on optical encoders versatile sensing. Link here (PDF) Linear and rotary encoders have come in a wide variety of design styles over the years, the most common being rotary switches, potentiometers, capacitive, magnetic, and optical types. The optical encoder has become the most popular of these encoding methods due to […]
Bus Pirate v3.8 PCB build
@EnJens tweeted, “Finally programmed my DYI Bus Pirate 3.8! It mostly works! Self test is slightly sad and power LED failing but it works!” 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 […]
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 […]
Yellowstone: Cloning the Apple II Liron
Steve writes: FPGA-based disk control for Apple II is finally working! Six months ago, I began designing a universal disk controller card for the Apple II family. Apple made a bewildering number of different disk controller cards in the 1970s and 80s, and my hope was to replace the IWM chip (Integrated Wozniak Machine) and […]
STM32F103 vs GD32F103 round 1: Solderability
Sjaak writes: I locked myself into the basement with a couple of PCBs, chips and fresh flux for a couple of days. For the STM32F103 vs GD32F103 challenge I needed to have two identical boards with a different microcontroller. As far as I could judge both chips are legit and not counterfeits as we bought […]
Measuring USB power cable voltage drop with my DC load
Dr. Scott M. Baker published a new build: This started when one of my raspberry pi projects failed due to voltage drop on the USB power cable that I was using, so I set out with my power supply and DC Load to measure the voltage drop of various cables that I use in my […]
#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 […]
Multicolor signal light with beeper
Multicolor signal light with beeper for ROS by Gal Pavlin When debugging algorithms in an autonomous vehicle a light that can show algorithm state in real time was proven to be effective for easier debugging and additional insight to what is going on in the code. Because all existing signal light were either to bulky […]
Troubleshooting tips: Failed debugging with GDB
Erich Styger writes: Three years ago I published “Debugging Failure: Check List and Hints” and unfortunately this article is one of the most popular ones: obviously debugging problems are very common. Debugging with GDB works usually fine, but if things are failing, then it can be hard to find the cause for it. Recently I […]
App note: Measuring inrush current
Inrush current evaluation from Aimtec. Link here In AC/DC power converters beyond a few watts, during the initial application of power an excessive inrush current will flow when the input capacitors are suddenly charged. If unhindered the inrush current can easily exceed 50 A at the peak of the AC cycle and severely stress the […]
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: Pulse width modulation (PWM) vs. Analog dimming of LEDs
App note from Aimtec on dimming LEDs. Link here With the phenomenal growth of the LED lighting market, there has been a natural growth in demand for highly efficient and controlled LED drivers. Applications from ‘smart’ street lights, flashlights, digital signage and many others require not only highly regulated currents, but in many cases dimming […]
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 […]
STM8 Microcontrollers
Here’s a three-part series of posts by Shawon Shahryiar detailing the STM8 microcontrollers: STM8 microcontrollers are 8-bit general purpose microcontrollers from STMicroelectronics (STM). STM is famous mainly for its line of 32-bit ARM Cortex microcontrollers – the STM32s. STM8 microcontrollers are rarely discussed in that context. However, STM8 MCUs are robust and most importantly they come […]
Custom 3D printed magnetic encoder disks for robotics projects
A how-to on making a custom DIY magnetic disk encoder by Erich Styger: I’m making great progress with the firmware for the new Mini Sumo Robot (see “New Concept for 2018 Mini Sumo Roboter“). The goal is a versatile and low-cost Mini Sumo robot, and the robot comes with the feature of magnetic position encoders. […]
ESP8266 Wi-Fi button – DIY Amazon dash button clone
Rui Santos over at Random Nerd Tutorials posted a step by step guide on building an ESP8266 Wi-Fi button: In this project you’re going to build an ESP8266 Wi-Fi Button that can trigger any home automation event. This is like a remote control that you can take in your pocket or place anywhere that when […]