Bidirectional detection with ultrasonic sensors @ ArduinotehNiq Check out the video after the break.
Author Archives: DP
#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 […]
Non-destructive testing of fuses
Kerry Wong discussed how to accurately determine a fuse’s current capacity non-destructively: A fuse is a sacrificial device for the protection the rest of the circuit in an over-current situation. There are situations we need to know with some reasonable confidence what the actual maximum current is for a given fuse without destroying it. This […]
App note: Designing RC snubbers
RLC snubber circuits, app note from Nexperia. Link here (PDF) This document describes the design of a simple “RC snubber circuit”. The snubber is used to suppress high-frequency oscillations associated with reverse recovery effects in power semiconductor applications
App note: Addressing floating inputs in digital systems (Bus Hold)
White paper from Nexperia about their bus hold tech. Link here (PDF) In the normal operations of a digital system, the input to any digital device within is clearly defined – it is either one or zero. There are however interface cases where outputs may be disabled that can result in floating inputs.
High-voltage FLASH programming on ATTINY85
ATTINY85 High-Voltage Flash programmer @ td0g.ca: The Atmel ATTINY85 is a great chip (cheap, easy to use, supported in the Arduino IDE). Unfortunately it only has 5 IO pins, which limits its usability. There are guides on using a High-Voltage Programmer (HVP) to change the Reset pin into an IO pin. However, that prevents you […]
Mechanical 7 segment display clock using an Arduino & 28 servos
Michael shows us how to build a mechanical 7 segment display clock using an Arduino and 28 servos: I built a countdown timer a couple of months ago using a two digit mechanical 7 segment display which was driven by 14 servos and an Arduino Mega. It came out quite well and a number of […]
Building a pulse oximeter
John Keefe made this DIY pulse oximeters, that is available on Github: The heart (ha) of the project is the Pulse Oximeter and Heart Rate Sensor, which includes the sensor itself, a tiny brain to make the measurement calculations, and two “Qwiic” connections. Qwiic is Sparkfun’s system of making it easier to wire up sensors. […]
An Isolated RS-422 / RS-485 Shield for the Automation Direct P1AM-100 Open-Source PLC
Glen @ bikerglen.com writes: The RS-422 / RS-485 shield is an open source shield designed to add RS-422 and RS-485 communication capabilities to the ProductivityOpen family of open-source programmable logic controllers (PLC’s) from Automation Direct. It’s loosely based on the Arduino MKR RS-485 shield but updated to use an ADM2582E 3.3 V isolated RS-485 transceiver […]
#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 […]
Deconstructing Sega’s System 16 security – part 2
Sega’s FD1089 security module reverse engineering part 2: The FD1089 module variants from Hitachi / SEGA were fabricated in a plastic case, on the back of the module a epoxy layer is visible together with two rows of pins arranged as DIP64. This arrangement mimics a standard 68000 CPU as intended by SEGA. The sample […]
App note: PoE Powered Device (PD) rectifier bridge circuits
App note from ON Semiconductors regarding different bridge rectifier topologies and how to reduce power losses in these stages. Link here (PDF) Power over Ethernet (PoE) is a technology which allows power sourcing equipment (PSE) to safely transfer power to a powered device (PD) through an Ethernet cable. The majority of the power transferred to […]
App note: Stepper motor module solution kit for LV8702V motor driver
Easily develop a motor conptrol application using this kit from ON Semiconductors without special knowledge of motor driver specs. Link here (PDF) This kit provides an API function library for motor driver control designed to control the ON Semiconductor motor driver product (LV8702V) via the Arduino Micro microcomputer. It also provides a dedicated GUI for […]
UHF version of TinySA
DuWayne KV4QB posted his UHF version of TinySA project: I had started on the TinySA from Groups.io HBTE, but am still waiting on some parts that I had orderd than have yet to show up. Looking around I found a UHF version that covers 240 to 940 MHz. This only uses a single si4432 transceiver […]
A circuit board from the Saturn V rocket, reverse-engineered and explained
Ken Shirriff writes, “In the Apollo Moon missions, the Saturn V rocket was guided by an advanced onboard computer system built by IBM. This system was built from hybrid modules, similar to integrated circuits but containing individual components. I reverse-engineered a circuit board from this system and determined its function: Inside the computer’s I/O unit, […]
Tinkering TI MSP430F5529
Shawon Shahryiar @ Embedded Lab writes: In my past tutorials on MSP430s, I demonstrated how to get started with MSP430 general purpose microcontrollers from Texas Instruments (TI). Those tutorials covered most aspects of low and mid-end MSP430G2xxx series microcontrollers. For those tutorials, TI’s official software suite – Code Composer Studio (CCS) – an Eclipse-based IDE […]
Signal generator control project
VE3POA published his DIY signal generator control project: I built a step attenuator, highlighted in 2 previous posts, and quite some time ago I experimented with the AD8307 logarithmic amplifier chip and have a couple of prototype circuits for measuring low power signals sitting around in the junk box. I have the prototype SigGen as […]
Intelligent 7-Segment display
An intelligent 7-Segment display based on Padauk MCU: I elected to use a PADAUK PFS154-S16 as microcontroller for each segment. This device has flash memory and sufficient I/O to control a 7 segment display without multiplexing. The cost is only $0.07, so it is cheaper than, for example, using multiple WS2811 instead. The data input […]
#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 […]
Dual Mono AK4493 DAC (MK II)
An update on Dual Mono AK4490 DAC project we covered previously: Since I was going to update the PCB design, I thought I might as well improve on as much as I could. So, the new board would: *Include a new reclocking solution. I went for the best specc’ed chip out there, the famous Potato […]