UHF label antenna design guide from NXP, app note here (PDF!) This document provides a general overview on basics of UHF wave propagation, as well as practical considerations of UHF label antenna design. The target is to guide the reader to a good understanding of UHF label antenna design in theory and in practice.
Author Archives: DP
SDI-12 USB + Analog prototype
Liudr has designed and built a SDI-12 + Analog USB adapter. Project info at Liudr’s blog.
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 […]
USB Infrared Toy free PCB build
Kai Bader built a free USB IR Toy PCB. With the USB IR Toy you can use a remote control with your computer, view infrared signals on a logic analyzer, capture and replay remote control buttons. If you build a free PCB we’ll send you another one! Blog about it, post a picture on Flicker, whatever […]
How does vacuum cleaner clean/dirty indicator work?
In this video, Kerry Wong examines how the clean/dirty circuitry from a Hoover vacuum cleaner works. Details at Kerry D. Wong blog.
#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 […]
Digipeater hardware build video
Kenneth Finnegan writes: This is the hardware build of a new digipeater one of my friends asked me to put together for him. The transceiver is a GM300, with a KAM plus TNC modulating it. If we didn’t happen to have a KAM+ on hand, I would have probably used an OT3m from Argent Data. […]
4-20 mA current output for Arduino Uno
Giovanni Carrera writes, “The purpose of this project is to provide a 4-20 mA output from a PWM signal generated by a microcontroller ATmega328 and numerous other chips, such as the PIC. One of the more interesting applications of this circuit would be to replace or to realize a smart sensor with Arduino.” More details […]
Inside a RFID race timing chip: die photos of the Monza R6
Ken Shirriff took some die photos of the Monza R6 chip and wrote a post on his blog on how the RFID timing chip works: I recently watched a cross-country running race that used a digital timing system, so I investigated how the RFID timing chip works. Each runner wears a race bib like 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: Hipot testing of magnetic components
High voltage test between two isolated coils for isolation handling an application note from Coilcraft. Link here (PDF) This application note discusses the purpose of hipot (high potential) testing and how the hipot test relates to inductor and transformer safety.
App note: SOLERIQ® L38
OSRAM’s filament looking LED application note. Link here (PDF) SOLERIQ® L38 (GW T3LxF1) is a filament LED with a beam angle of 360deg for indoor retrofit lighting applications. It combines the advantages of modern LED technology with the aesthetics of traditional light bulbs. The construction of the SOLERIQ® L38 consists of a ceramic based frame […]
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 […]
DIY Arduino ProMini data logger
Ed Mallon blogged about his DIY ProMini data logger build: Typical pro-mini loggers built with this design sleep at 0.25mA, before extra sensors are added. At that current draw, the logger should deliver approximately six months of operation on three brand new AA batteries with a 15min duty cycle; depending on sensor load.
Fan controller project
Lucky Resistor has written up documentation on his fan controller project: The fan controller described on this project page, controls one or more PWM controlled 12V PC fans. It uses the input from two precise DHT22 based temperature sensors. The MCU is an Arduino Uno, which is powered using a 12V power source. On top […]
Tear down of a scientific calculator Integrated Circuit
A detailed video teardown of a scientific calculator Integrated Circuit from Electronupdate. More info at Electronupdate blog.
Linear MOSFET and its use in electronic load
Kerry Wong writes, “In this video, I discussed some limitations of regular power MOSFETs when operating in linear region and demonstrated the superior performance of linear MOSFETs as electronic load.” More details at Kerry Wong’s blog.
App note: Magnetometer placement in mobile devices
Correct magnetometer placement app note from Kionix. Link here (PDF) Electronic devices contain many parts which can affect a magnetic sensor. When deciding the mounting position, it is necessary to consider the types of materials and the amount of current carried in proximity of the magnetic sensor. Accuracy of an electronic compass depends upon getting […]
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: Embedded orientation detection using the MMA8450Q
NXP’s accelerometer chip MMA8450Q, provides orientation detection on handheld devices. Link here (PDF) This application note targets the portrait/landscape orientation detection feature which has become standard in many hand-held electronic devices. Additionally, this application note aims to explain uses as well as highlight some of the challenges of designing an embedded algorithm into the sensor. […]