Mare writes, “This is description of coaxial collinear antenna for 868MHz applications. I designed this for Lorawan gateway.” Project info at Mare & Gal Electronics homepage.
Author Archives: DP
Traktorino, an open source DIY MIDI controller
Here’s an Arduino based open source MIDI controller by Musico Nerd, the Traktorino: The Traktorino is a powerful low-cost DIY MIDI Controller. It is based in the Arduino platform and it comes in DIY kit, or assembled. In its core, there’s a shield that connects to an Arduino Uno, which uses open-source code, making it […]
#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 […]
Taito C-Chip: data by lobotomy
CAPS0ff writes: In a previous post we described some early attempts to analyze the Taito C-Chip. See Haze’s forum post for some background on the C-Chip itself. In particular we’re interested in the EPROM. Previous efforts focused on less invasive techniques with the goal of keeping the C-Chip alive after dumping. Unfortunately, we’ve been unable […]
App note: Performance of noise canceller of LC823450
Audio Noise cancelling LC823450 from ON Semiconductor. Link here (PDF) This application note describes the performance of Noise Canceller of LC823450 Series. The customer can improve of audio characteristics by using this canceller. Its function can be used for various products such as Wireless headset, Earbads, Wireless speaker or IC−recoder.
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: Performance of echo canceller of LC823450
Audio application echo canceller LC823450 from ON Semiconductor. Link here (PDF) This application note describes the performance of Echo canceller of LC823450 Series. The customer can improve the sound quality of hands free communication by using this canceller. Its function can be used for various products such as Wireless headset. Earbads or other voice communication […]
‘Daytime Running Light’ module (DRL) with ATtiny85
Nicu Florica writes: A reader of my sites and blogs, Mr. Liviu Hinoveanu wanted to replace classical DRL module made with 555 with Attiny85 programmed in Arduino style. He send me the schematic and PCB designed with Livewire and PCB Wisard software After I undertand what module must work, I write DRL_ATtiny85.ino sketch. Mr. Hinoveanu […]
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 […]
MFJ-1708SDR transmit/receive switch for SDR receivers
Here’s a demonstration of the MFJ-1708SDR transmit/receive automatic relay switch from YouTube channel HamRadioConcepts . Here is an interesting device, for use with your SDRplay or other SDR dongle for receive. You can share your current antenna with your 100 watt HF rig and an SDR for receive.
DEC PDP 11 / 24 CPU CARD: State of the art design from 1979
DEC PDP 11/24 CPU card teardown from Electronupdate: This is a cpu card from a class of computers known as mini-computers. By the late 1970’s DEC was about to be eclipsed by the microcomputer. At the same time this card was in production the 68000 and 8086 16-bit class micro processors were also in the market: […]
Automatic fan controller for server racks
Dilshan Jayakody published a new build: In this post we describe fan controller which we designed for our 9U wall mount server cabinet. This fan controller is designed to drive a 12V DC cooler fan with pre-configured intervals or by monitoring the temperature of the server cabinet. Core components of this fan controller is CD4060 […]
Negative impedance converters
An article discusses the negative resistance and negative impedance converter from Analog Zoo: “Negative resistance” may seem like a purely academic concept, but can be easily realized in practice with a handful of common components. By adding a single resistor to a standard non-inverting op amp circuit, we can create a negative impedance converter, which […]
Why electrolytic capacitors are actually kinda shitty
Afroman writes, “Electrolytic capacitors are common, but knowledge of their limitations is uncommon. A demonstration is shown highlighting the difference in performance between electrolytic and ceramic capacitors in power supplies. Other topics discussed in the video: Electrolytic capacitor construction, ceramic capacitors, ESR, ESL, impedance curves, why “0.1uF”, and more.” Via Afrotechmods. Check out the video after […]
Alexa (Echo) with ESP32 and ESP8266 – Voice controlled relay
Rui Santos writes, “In this project, you’re going to learn how to control the ESP8266 or the ESP32 with voice commands using Alexa (Amazon Echo Dot). As an example, we’ll control two 12V lamps connected to a relay module. We’ll also add two 433 MHz RF wall panel switches to physically control the lamps.” More […]
Reading a VGA monitor’s configuration data with I2C and a PocketBeagle
Ken Shirriff wrote an article showing how to read the monitor’s config data using the I2C protocol and a board with an I2C port: Have you ever wondered how your computer knows all the characteristics of your monitor— the supported resolutions, the model, and even the serial number? Most monitors use a system called DDC to communicate […]
#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 […]
Curiosity Mars Rover
The Curiosity Mars Rover project from Beatty Robotics: We are excited to share our latest and most ambitious robot, the Curiosity Mars Rover. This is a highly-interactive, 1/10th scale functional replica of the NASA Curiosity Mars Rover. This project was ambitious for us in two main ways: First, we worked very hard to make the […]
STM32F103 vs GD32F103 round 3: UART
Here’s the part 3 of Sjaak’s post comparing the GD32 to the STM32: Since the GD32F103 can run as fast as 108MHz but has not a proper USB clock divider to provide a 48MHz clock for USB communication we need another way to communicate with the outside world. Since the early days of computing the easiest […]
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 […]
