KF5OBS writes: This article shows how to use off-the-shelf parts to improve the performance of a radio scanner in the 800 – 900 MHz band. Furthermore, it shows how to expand radio coverage by using two different receive antennas at the same time. For some reason, my new BCD996XT scanner wasn’t working as expected on […]
Author Archives: DP
Omnivision OV9650 Breakout
Mux blogged about his breakout for the OV9650, all files are available here: I made this breakout for the OV9650 a while ago, and I’ve been waiting to test it before sharing, I finally had the chance to do so, I used an FPGA this time for testing, and here’s the result. The breakout has two SOT23 […]
Serial AVR and PIC programmer
Dr. Ayman Shalaby over at Electronics Lab posted another project, a serial AVR and PIC programmer: This is a dual MCU programmer which supports both AVR and PIC mcu and there is a switch to select between them. It’s easy to manufacture and have only through hole parts. Features – RS232 Serial interface – AC-DC […]
#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 […]
Bus pirate used to hack into a car
Nilsson writes to inform us that he spotted a Bus Pirate in a video from Vice News, “How to hack a car: Phreaked Out (episode 2)” From his laptop, he was able to manipulate the car’s engine, brakes and security systems by wirelessly tapping into the Controller Area Network, or CAN bus, network. Without getting too deep into […]
LCD clock version 2 – part II
Here’s an update on Kevin Rye’s LCD clock we covered previously. Source files are available here, for direct download LCD-Clock-V2-Source.zip: Once all the components and headers were soldered in, I attached my Arduino and configured it as an ISP. I then burned the bootloader for an Arduino Uno. I then connected my FTDI programmer and uploaded the blink […]
Simple LED driver/constant-current source 20 mA
Another Instructable by Jan Henrik, a constant-current source which gives 20mA at the output. He writes: It is a circuit, which limits the current to 20mA, what allows us to drive any normal led, without calculating a resistor, you can just plug the led in and see it emitting light… Also this allows us to test […]
EGYDuino – Arduino compatible board
Dr. Ayman Shalaby over at Electronics Lab has posted an article describing EGYDuino, an Arduino compatible board that can be build using home process: EGYDuino is a DIY Arduino clone made on a single sided PCB board. It’s simple and cheap to build using home PCB fabrication methods and it’s 100% compatible with Arduino.
The easy peasy stepper driver/stepper motor test circuit
Rohit Gupta writes: I made a very easy to make stepper driver and motor tester that could be useful to people working with steppers for 3D printers or CNC. I saw an article a while back here on DP and HackADay itself that used a controller (ATiny45 i guess). I thought it would be useful […]
Bubble display alarm clock
Markus Gritsch build another bedside table alarm clock, the schematic and source code is available here: recently some vintage bubble displays popped up at various places [1][2], so I felt the urge to build another bedside table alarm clock, this time a really tiny one, roughly the size of an AAA battery. Check out the video […]
app note: Digital Potentiometers: Frequently Asked Questions
FAQ on Analog Device’s digital Potentiometers. App note here. A digiPOT is a digitally controlled resistor that changes the impedance between the terminals and wiper depending on the code loaded in the RDAC register. Digital potentiometers avoid the problems that mechanical potentiometers face, such as physical size and wear and tear, as well as sensitivity […]
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: How to Oversample 5 MSPS, 18-Bit/16-Bit Precision SAR Converters to Increase Dynamic Range
Here’s how you can maximize your ADC’s Dynamic Range by oversampling, an app note from Analog Devices. One of the ways to achieve a higher dynamic range is to oversample the converter to accurately monitor and measure both small and large input signals from the sensors. There are a number of other ways to increase […]
App note: Introduction to SHA-256 Master/Slave authentication
An application from Maxim: Introduction to SHA-256 Master/Slave authentication A new group of secure authenticators and a companion secure coprocessor/1-Wire® master implement SHA-256 authentication. This application note explains the general logistics of this SHA-256-based security system and introduces the bidirectional authentication functionality that the authentication system uses.
Stencil printer project
Supertronic posted pictures of his new stencil printer design in the forum: I did a new stencil printer design it will be avaliable before machine production starts. It can print 300x200mm stencils and is used for prototyping.
LCD clock version 2 – part I
Kevin Rye posted an update on his LCD clock project: Now that I’ve spent some time working with SMD Atmegas, I decided to redo the PCB to make it all SMD. By moving the Atmega to the SMD version, I picked up some additional space on the PCB. That allowed me to add a 4th button […]
Free PCB coupon via Facebook to 2 random commenters
Every Friday we giveaway some extra PCBs via Facebook. This post was announced on Facebook, and on Monday we’ll send coupon codes to two random commenters. More PCBs via Twitter on Tuesday and the blog every Sunday. Don’t forget there’s free PCBs three times every week: Free PCB Sunday. The classic. Every week, get free […]
Week in (p)review May 30, 2014
Here’s a summary of major developments over the last week. Free PCB Friday is coming up soon. NEW PROTOTYPE: Premium Make Your Own Keyed Cable Kit Bay Area Maker Faire 2014: Booths and Exhibits Bay Area Maker Faire 2014: Robots! Bay Area Maker Faire 2014: Cool stuff Getting around at Bay Area Maker Faire 2014 […]
Temperature compensation for an Arduino ultrasonic distance sensor
Sverre Holm writes: Ultrasonic distance sensors can find the range out to 2-4 meters and are popular in e.g. robotics. Here I look at how the accuracy can be improved by compensating for the variation of speed of sound with temperature. It actually varies quite a lot in air and around 0 C it is: […]
USB-to-UART CP2104-MINIEK (mini evaluation kit) available for $5
Viswa wrote to us about the USB-to-UART CP2104-MINIEK (mini evaluation kit) from Silicon Labs available for $5. Via the contact form.