Controlling an HMC624LP4E RF attenuator using Arduino

Kerry Wong writes: For simplicity, I used a single rotary encoder for controlling the attenuation. In order to prevent accidentally changing the set attenuation value, I used the built-in switch of the rotary encoder as the lock/adjust control. The idea is that the attenuation value can only be adjusted when the switch is in the […]

Tiny, isolated USB to Xcvr interface (PTT, Audio, CAT, …)

Mare writes: I will describe here the USB interface between the radio station and the computer which I recently developed and tested. This post is a continuation of the first part, where I described a simple interface for controlling two digital lines using the USB / Serial Converter, where I presented simple interface to control […]

Programming an 8 digit 7-segment display, the easy way, using a Max7219

Allan Schwartz shows off the easy way to interface 7-segment displays using the MAX7219: Previously, in part 1 of my blog posting Programming a 7-segment Display, using just Arduino digital pins (the hard way) we had demonstrated how to hook up a pair of 7-segment displays to an Arduino, treating each individual segment as a […]

Interfacing PIR sensor to 8051 microcontroller

Praveen from CircuitsToday has written up an article on interfacing PIR sensor to 8051 microcontroller: PIR sensors are widely used in motion detecting devices. This article is about interfacing a PIR sensor to 8051 microcontroller. A practical intruder alarm system using PIR sensor and 8051 microcontroller is also included at the end of this article. Before going in […]

iButtonLink T-Sense 1-wire sensor (Maxim DS18B20) + PIC 18F14K22

Chas over at PNW/Electronics writes: I came across a stash of iButton T-sense 1-wire sensors.. so I grabbed a couple and decided to check out 1-wire. Maxim makes a 1-wire device called the DS18B20. It’s a 9-12 bit temperature sensor with the possibility of being powered by parasitic power from the data line. This cuts […]

RadioduinoWRT – a do it yourself webradio

Raffael Herrmann wrote in to let us know about his latest project the RadioduinoWRT – a do it yourself webradio: In the last weeks I built a webradio by myself. It made from an Arduino, an hacked TP-Link WR703N router and some interface parts. It’s fitted into a beautiful Yamaha enclosing and supports the original Yamaha interface, […]

High-voltage seven segment LED display driver with SPI interface

Raj writes: This is about my new project, which is a High-Voltage Seven Segment LED Driver with a serial interface. The goal is to simplify the interface of bigger seven segment display modules to 5V microcontrollers. The project provides a TTL SPI interface of MAX7219 to input display data from a 5V microcontroller and outputs […]

Interfacing TLV5620 With Arduino

Kerry Wong posted an article on interfacing the TLV5620 with an Arduino: TI’s TLV5620 is a budget 4-channel 8-bit DAC. While it is designed primarily for running with a power supply between 3V and 3.6V, it can be powered by 5V as well given its wide supply voltage range. With a TL431 voltage reference (2.5V), the DAC output can cover […]

Energia Library : Interfacing to a Mifare RC522 RFID

Eelcor over at the 430h forum shared his Energia library for the Milfare RC522 RFID card: I wanted to share my results with the MF RC522 RFID reader. I found an article from Grant Gibson where he used a cheap reader from eBay to read Mifare cards. The command set and technical aspects of the […]

USB custom hardware interface for Unity3D

Here’s a video by Dilshan Jayakody demonstrating the USB custom hardware interface for Unity3D: The custom hardware unit used in this demo is build around Microchip’s PIC18F2550 MCU. This custom USB controller consists with 4 push buttons and linear potentiometer. In supplied demo user needs to control aircraft with those buttons and potentiometer. According to […]

Amazing new touchscreen interface

Fujitsu Laboratories: Touchscreen interface for seamless data transfer between the real and virtual worlds This new gadget comes directly from Fujitsu Laboratories. They developed what seems to be the next generation of user interface! It can accurately detect the operator’s fingers and hand, and can react to certain movements and gestures. A projector from above […]

The Descriptive Camera

Matt Richardson’s Descriptive Camera sends pictures to Amazon’s Mechanical Turk where a worker writes a description of the scene: The Descriptive Camera works a lot like a regular camera—point it at subject and press the shutter button to capture the scene. However, instead of producing an image, this prototype outputs a text description of the […]

How to read several infrared sensors using one MCU pin

Oscar has written an article describing a technique he’s used for reading multiple analog sensors with one MCU ADC pin. He was designing a line-following robot and wanted to read several infrared sensors without having to dedicate an analog read pin for each. His solution uses “a Schmitt trigger inverter whose output has resistors connected […]

Cheap light-based PC to microcontroller communication

We’ve seen some pretty cool projects that use blinking lights on a PC monitor to transfer data to a microcontroller. We did a little research, and here are some example projects we’ve found. This project uses two photo transistors to read a bar code from the monitor. One handles the clock, while the other has […]