David Johnson writes: This is a small board that plugs into one of the headers on an Arduino Uno or other board to provide 4Mbytes of non-volatile storage It works with either 5V or 3.3V boards, and is based on the low-cost 4Mbyte Winbond W25Q32FVSIG DataFlash chip. It is ideal for applications such as data […]
Author Archives: DP
App note: Comparison of LED circuits
Another application note from OSRAM on different LED circuit design failure mode. Link here (PDF) In recent years, Light Emitting Diodes (LEDs) have become a viable alternative to conventional light sources. The overriding advantages long life, high efficiency, small size and short reaction time have lead to the displacement, in ever increasing numbers, of incandescent […]
App note: Dimming LEDs with respect to grouping current
App note from OSRAM describing the behaviour of LEDs in respect to brightness by varying the current and to suggest solutions for avoiding negative influence for the application. Link here (PDF) In the design of a driving circuit for LEDs, the dimming behaviour is an important topic to fulfill the end customer requirements. The behaviour […]
Building a bluetooth DAC with Raspberry Pi Zero W
Sami Pietikainen has written an article detailing the build of his Bluetooth DAC using Raspberry Pi Zero W: My car comes with a built-in Bluetooth hands-free but unfortunately it does not support audio streaming. Luckily there is an AUX input available which uses a regular 3,5 mm jack. Perfect opportunity for a DIY project. I built the […]
A DIY SMD pick and place tool for electronics assembly
Here’s a DIY vacuum pick-up tool for SMD components: This video describes a DIY Vacuum Pick-up tool for picking and placing parts from an SMD component tape. The basic design for this tool involves using a vacuum pump and a solenoid to control the vacuum to a handpiece under control of a foot pedal. Via SDG […]
Looking inside a 1970s PROM chip that stores data in microscopic fuses
Ken Shirriff did teardown of a 1970s PROM chip: The MMI 5300 was a memory chip from the early 1970s, storing 1024 bits in tiny fuses.1 Unlike regular RAM chips, this was a PROM (Programmable Read-Only Memory); you programmed it once by blowing fuses and then it held that data permanently. See the full post […]
#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 […]
Programmable seven segment LED tester
A Seven segment LED tester project from Arduino Enigma: Here is the finished Seven Segment Tester. All of the available Arduino Nano pins, except for analog input pins A6,A7 and Serial Port pins D0 and D1 are connected. This leaves us with 18 pins to bring to the 3M Zero Insertion Force (ZIF) socket. Any […]
63 dB step attenuator
DuWayne published a new build: While I was working on the power meter function for the latest version of the SNA, I used several fixed attenuators for checking linearity and calibration. It would be a lot easier if I had a variable step attenuator. I have several digital controlled attenuator modules that I bought one […]
App note: Passive entry door system with proximity sensor
A full implementation of a keyless entry from Microchip. Link here (PDF) The door access systems have evolved from simple physical keys to more sophisticated keyless entry systems. Now, we have a system that automatically unlocks the door when user carrying an access key approaches the door handle. As it does not require any user […]
App note: Low Power POE Flyback Converter
App note from Microchip about their MIC2145 boost switching regulator to do POE Flayback conversion. Link here (PDF) The MIC2145 skip mode controller is used to implement a flyback converter that is intended for use in nonisolated, low power, POE applications. The circuit has a nominal 48V input and supports the POE voltage range of […]
Open source hardware ESP32-ADF
Here’s an open source hardware development board for Espressif audio development framework, the ESP32-ADF, from Olimex: With ESP32-WROOM-B module with 8MB RAM and 4MB of Flash, two microphones, two 3W speakers, codec, amplifier, Lipo charger, USB with programming, Audio 3.5mm jack, ESP32-ADF board offers everything you need to start playing with Espressif Audio Development Framework. Check […]
Arduino brushless motor control tutorial
Dejan over at HowToMechatronics.com shared detailed tutorial on how to control brushless motor using Arduino and ESC. Check out the video after the break.
DC40 receiver
Michael LeBlanc has a nice write-up on building a direct conversion radio receiver: In the late winter of 2018-19, I decided to build a receiver that would provide a performance improvement to the regen I built a couple of years ago. I wanted the radio to receive AM and SSB signals between 160m and 20m […]
#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 […]
rePalm
rePalm project from Dmitry.GR As I mentioned, none of the native API of PalmOS 5.x was ever documented. There was a small number of people who figured out some parts of it, but nobody really got it all, or even close to it. To start with, because large parts are not useful to an app […]
App note: Consideration of self pollution reduction for electronic systems
App note from ON Semiconductors on EMI self pollution. Link here (PDF) This application note will address the problem of Electro Magnetic Interference (EMI) self pollution in which one part of an electrical systems such as cell phones and consumer electrical products emit radiation that interferes with the operation of other parts of the system.
App note: 1 kV SenseFET integrated power switch
App note from ON Semiconductors on their FSL4110LR power switch for SMPS power supplies. Link here (PDF) Some industrial equipment that are supplied from a threephase AC power source such as industrial drives and energy meters often need an auxiliary power supply stage that can provide a regulated low-power DC source for analog and digital […]
Temperature/weather station
B. Perry writes: I’ve always been fond of the popular Nixie clocks made from old surplus Soviet nixie tubes. Nixie tubes are no longer made, so they’re hard to acquire. Instead, I took inspiration from “Lixie” displays and made my own Nixie-inspired, LED-powered display. And in an unusual twist (for me, anyway), I didn’t make […]
A low cost 2-4 GHz Downconverter from off the shelf dev boards
Ian Wraith designed and built a low cost 2-4 GHz downconverter for an SDR, that is available on Github: I recently became interested in exploring some of the signals found in the 2.4 GHz ISM band. The problem is that my favourite SDR (Software Defined Radio) an Airspy R2 only covers up to 1.7 GHz. Initially […]