Tomasz Watorowski has published a new build, a NE612 RTL SDR Upconverter: This is a simple yet completely functional upconverter for the popular SDR donlge. The construction was build around cheap and easily obtainable mixer IC marked as NE 612, manufactured by Phillips Semi. Despite its limitations, it performs outstandingly well, at least when price-to-quality factor […]
Author Archives: DP
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: EMC guidelines for microcontroller-based applications
Application note(PDF) specific on microcontroller EMC from ST Microelectronics. Electromagnetic compatibility (EMC) must be taken into account at the very beginning of a project as the cost of correcting an EMC problem encountered at the start of production can be far greater that the cost of a detailed EMC study during the development phase of […]
App note: EMC general information
Application note(PDF) on EMC from ST Microelectronics. Because many electronic circuits are in proximity to each other, it is essential that their design is not affected by external noise sources and that the circuit itself is not a noise source affecting other circuits. This relationship is known as electromagnetic compatibility or EMC. Sources of electromagnetic […]
App note: Operational amplifier applications using 8-Bit PIC microcontrollers
Operational amplifier applications using 8-Bit PIC microcontrollers (PDF!) from Microchip: This document aims at uncovering some of the more important parameters of the op amp and the significance in certain applications. Specific examples and case studies of applications using the on-chip op amp of the PIC16F families of microcontrollers will be discussed. A comparison of the […]
DirtyPCBs two layer ENIG PCB closeups
DirtyPCBs two layer ENIG PCB review by manis404: The standard service is $14 for 10 boards. You can have the pads ENIG finished for $15 more, which brings the total cost to $29 for 10 boards, shipped. It is still an excellent deal. The quality is excellent too, as the closeups below illustrate. See more […]
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 times every […]
Raspberry Pi Videolooper
Steven Hickson writes: Introducing videolooper 3.0! This image is compatible with the A,B,B+, and B 2 versions. I have a brand new version of the Raspberry Pi Videolooper that is compatible with the new B V2 and has a bunch of new features that streamline it for easy use. It can now loop one video […]
Towards a simple solder-paste extruder
Peter wrote an article detailing his prototype solder-paste extruder: The prototype that I put together is more of a sketch in hardware to help me appreciate the issues of paste extrusion, and help hammer out a design. Instead of using a plunger, I’ve used a very long lead screw that acts as the plunger, and has a […]
Using RFM69CW instead of RFM12B
Martin writes: The rumors for RFM12B’s end-of-life two years ago seem to have been highly exaggerated now and the popular RF module is still available in abundance. HopeRF has introduced a pin-compatible upgrade, the RFM69CW. The module itself offers improved sensitivity and range compared to the RFM12B (+30%) at the cost of increased power consumption, […]
New Energia version available
The Energia team announces the availability of version 0101E0015: The Energia team is very happy to announce the release of Energia 15. This release aside from bug fixes adds support for the new Texas Instruments ARM Cortex M4F based MSP432 LaunchPad. This time around it’s a bit different though. The MSP432 Wiring/Energia framework is […]
AD9850 DDS VFO
Richard Visokey of AD7C made a DDS VFO using AD9850 and an Arduino Uno: I built a simple VFO for a direct conversion receiver I am putting together. The VFO uses an AD9850 DDS chip to synthesis a nice 1Vp-p sinusoidal wave. I used an Arduino Uno to set the AD9850 frequency, drive an LCD display, […]
TI releases the MSP432 microcontroller
Introducing MSP432: MSP’s new low-power 32-bit ARM® Cortex®-M4F MCUs TI is announcing an expanded MSP portfolio including a new family of 32‐bit processors built on the ARM Cortex‐M4F core. The first family includes the MSP432P401x MCUs with 48MHz speed, 1MSPS 14‐bit ADC, up to 256KB flash, up to 64B RAM and low‐power operation of only […]
RainCloud Umbrella Minder v2
Do you always forget your umbrella whenever it rains? No more! Jeremy Blum shows you how to easily make a RainCloud Umbrella Minder: The RainCloud is a web-connected smart umbrella holder. Built around the LittleBits Cloud Bit, the RainCloud allows you to tell with a glance if you need to bring your umbrella with you for the […]
#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 […]
FRDM-KL25Z Arduino headers with Altium
Erich of MCUonEclipse writes, “In case you are using Altium to design your boards, then this one might be useful for you. I have have posted the Altium .SchLib and .PcbLib files on GitHub here” Details at MCU on Eclipse.
Free cable build (no PCB this time…)
hlipka posted picture of his free cable build. The Premium Make Your Own Cable Kit contains enough connectors to make an (almost) lifetime supply of cables for standard 0.1″ (2.54mm) headers. Via the forum.
KeySweeper – covert Microsoft wireless keyboard sniffer using Arduino and nRF24L01+
Samy Kamkar has written an article detailing the build of his KeySweeper project: KeySweeper is a stealthy Arduino-based device, camouflaged as a functioning USB wall charger, that wirelessly and passively sniffs, decrypts, logs and reports back (over GSM) all keystrokes from any Microsoft wireless keyboard in the vicinity. All keystrokes are logged online and locally. SMS alerts […]
Low power magnetic hold and release mechanism
This video by Shane Ormonde discusses the low power magnetic hold and release mechanism: With the inductor and magnet combined, ferrous metal objects can be held without any power indefinitely. To release the metal object the magnetic field holding it up needs to be temporarily cancelled out. This happens by pulsing current through the inductor which generates […]
AVR timer-based one shot explained
Josh writes: Last time, we made one-shot pulses using the AVR’s built in hardware timer module. Today we are going to dive deep into the datasheets to see how this technique is able to coax the normally free-running timer into generating a single pulse. Along the way, we will learn about the low level rules […]