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 […]
Author Archives: DP
Fun with Analog multipliers: Squares, cubes, and VCAs
Craig writes, “Need a frequency doubler? Want to plot a cubic function on your ‘scope? How about a square root extractor, or a voltage controlled amplifier? Analog multipliers make all this (and more) a snap!” Details at Analog Zoo homepage.
Georges F6DFZ’s very stylish homebrew version of the Scout Regen receiver
Dave Richards AA7EE has published an article about Georges F6DFZ’s homebrew regen receiver: Several months ago, Georges F6DFZ sent me pictures of a Manhattan project he had just completed, using Rex’s MeSQUARES, and I have waited far too long to share it with you. It began life as a copy of the Ten Tec 1253 regen, but […]
HydroBot
Matthew Reed writes: HydroBot is a modular control system for automating hydroponic gardens. This system is designed with three objectives in mind. First, it will facilitate optimal growing techniques by using scheduling and feedback control loops to maintain state and adapt to changing conditions. Second, it will simplify controls interfaces, making setup and use easier […]
App note: Limiting inrush current
Aimtec’s app note on inrush current on power converters and their solution. Link here Inrush currents can be problematic in circuits that utilize overload protection devices such as fuses and circuit breakers. The selection of overcurrent protection devices is made more complicated when high inrush currents are present. False overload conditions can trigger unwanted protection […]
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: Forced air convection and heat sinking for power supplies
Application note from Aimtec discusses about two ways for taking away heat on power supplies. Link here When evaluating the operating temperature ranges of power supplies one must consult component’s datasheets. Datasheets state a “usable” operating temperature range typically given at full output load. In order to reach the upper limit of the temperature ranges […]
App note: System design guidelines for the TM4C129x family of Tiva C series microcontrollers
System design guidelines from Texas Instruments for the TM4C129x Tiva C series microcontrollers, app note here (PDF!): The Tiva™ C series TM4C129x microcontrollers are highly-integrated system-on-chip (SOC) devices with extensive interface and processing capabilities. Consequently, there are many factors to consider when creating a schematic and designing a circuit board. By following the recommendations in […]
Reaction tester
Reaction tester project from Vagrearg: The single gate-type NAND version was put onto a PCB and tested. It works like a charm. There were only 74AC00 chips available at the time, but they are just about the same as HC chips. You can get the design files, which are made with KiCad. The layout is […]
Pi Zero POV
Francesco over at Garage Tech posted a detailed how-to on building a Raspberry Pi Zero POV setup to display text from a file using an LED: The most important part of getting the Pi Zero POV to run smoothly is given by how do you fix the payload of this spinning rocket onto the CD. […]
DIY smart glasses
Harris has been working on his DIY smart glasses: The glasses themselves are based around an STM32F051K8 microcontroller (LQFP32 for easy soldering!). All the firmware is custom written though I got the LCD driver initialization codes from the BuyDisplay examples. The firmware is written using a somewhat “co-operative scheduling” with interrupts methodology and for most […]
ATtiny based bidirectional motor control using L293D
Rahul over at Xanthium has posted a tutorial on interfacing ATtiny with L293D: In this tutorial we will learn to interface L293D with ATMEL ATtiny microcontroller and control them bidirectionally.The microcontroller used here is ATtiny2313A which is interfaced to two L293D motor control chips for controlling upto 4 DC brushed motors.You can control upto 8 […]
Programmable relay switch using PIC MCU (revised version)
Raj has documented his DIY programmable relay switch using PIC16F1847 microcontroller: Here are the summary of the features that this programmable relay switch has: On-board +5V voltage regulator (operates at 9-15V DC input) OFF and ON time setup for the relay operation Option for cyclic run (maximum 100 cycles, after which the timer stops automatically) […]
Failure analysis of a dead MOSFET and a power diode
This video discusses the failure analysis of a MOSFET and power diode by Electronupdate.
SNAFU box
A SNAFU box project by Bertho of Vagrearg: SNAFU Box consists of 24 LED strips (12V passive type) of varying size, which are controlled by a set of 74HC595 shift-registers and a transistor driver for each strip and RGB channel. The LED strips are used to backlight the lettering of the box. An additional three 74HC595 […]
Wavetek 395 arbitrary waveform generator teardown
Kerry Wong did a teardown of the Waveform 395 12 bit arbitrary waveform generator: I picked up a Wavetek 395 arbitrary waveform generator on eBay a few weeks ago. Wavetek 395 is a single channel, 12-bit resolution DDS AWG with a maximum clock frequency of 100 MHz. While the operation manual is readily available, I […]
#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 […]
“Hello world” in the BCPL language on the Xerox Alto simulator
Ken Shirriff writes: The first programming language for the Xerox Alto was BCPL, the language that led to C. This article shows how to write a BCPL “Hello World” program using Bravo, the first WYSIWYG text editor, and run it on the Alto simulator. The Xerox Alto is the legendary minicomputer from 1973 that helped […]
More Delta printer upgrades: WiFi and silence!
David Crocker has been working on his Delta 3D printer project: After performing this upgrade, the printer is much quieter than before. This is because of the change from x16 microstepping on the Duet with A4982 drivers, to interpolated x256 microstepping on the Duet WiFi with TMC2660 drivers. The noisiest component is now the 40mm electronics […]
Make the world’s cheapest MIDI tester
Jesse from Bent-Tronics has posted a tutorial on how to make a DIY MIDI tester: A quick and dirty (and cheap) MIDI tester. Sometimes you just need to know if a MIDI controller is outputting anything. Even many high-end MIDI modules/boxes will have a “MIDI Activity” light, just to let you know something is being transmitted/received. That’s […]