Category Archives: Featured


Product review: Elecrow’s 7″ HDMI LCD Display for Raspberry Pi

A colorful LCD display is always a great add-on to any Raspberry Pi project. This article provides a quick review of a high resolution (1024×600 pixels) 7″ HDMI LCD product from Elecrow and illustrates a simple way to set it up for Raspberry Pi. With HDMI support, built-in capacitive touchscreen control, and 4 mountable corners, this LCD is a perfect Plug-n-Play display for use with single board computers like Raspberry Pi and Banana Pi. It comes with an HDMI cable for the display, an USB cable for touchscreen control, four mounting screws, and a DVD containing the driver softwares. Hardware connections and software setup The setup

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Serial seven segment LED display shield

Seven segment LED displays are brighter, more attractive, and provide a far viewing distance as well as a wider viewing angle compared to LCD displays. This project describes a serial seven segment LED display shield for Arduino Uno or compatible boards. The shield consists of eight 0.56″ seven segment displays that are driven by one MAX7219 chip. The shield also features a light dependent resistor (LDR) to implement adaptive brightness control to the LED displays. The LDR output can be fed to A0 or A1 analog input channel of Arduino to read the surrounding illumination level. Arduino can then use that

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Controlling relay switches with an infrared remote

The infrared (IR) communication technology, which existed long before WiFi and Bluetooth, is still a key component in implementing major components of a typical home automation system. For example, IR technology is still used in cordless headphones, for intrusion detection in home security systems, and in handheld remotes for controlling home entertainment systems (TV, DVD, soundbox, etc), air-conditioning units, and other household appliances. Because IR technology requires a line-of-sight between the transmitter and receiver units, it can only be used for connecting devices in short range, like in a same room. In one of my previous articles, I wrote about a simple IR

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How to post data to Google sheets using ESP8266

In the past couple years, the ESP8266 platform has flourished dramatically and emerged as one of the most popular hardware tools among electronics hobbyists and IoT enthusiasts. Packed with a 32-bit RISC CPU running at 80 MHz, a fully integrated WiFi radio with TCP/IP protocol stack, serial peripherals (I2C, SPI, and UART), an ADC channel, and general purpose I/O pins, the ESP8266 is the most integrated and affordable WiFi solution available in the current IoT market space. An ESP8266 hardware, like NodeMCU and ESP-01, can directly interface with sensors using its peripherals and upload the sensor measurements to a local

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Making an Ultrasonic Anemometer

An anemometer is a common instrument at a weather station. It is used to measure the wind speed and wind direction. The most common type of anemometer uses mechanical sensors consisting of three or four hemispherical cups mounted on horizontal arms on a vertical rod. As the wind blows, the cups are pushed causing the arms to rotate at a rate proportional to the wind speed. In addition, a wind vane connected to the anemometer can give the direction measurements. While the cup and vane anemometers are very popular due to their very simple design, they can be susceptible under cold and humid conditions

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