DIY LC meter projects are very popular among hobbyists and students. Here is another LC meter project which is based on PIC16F628A microcontroller. It uses a tank oscillator circuit combining a few external components and PIC’s internal comparator module. The L and C values are computed from the resonant frequency of the LC tank circuit. The project also incorporated auto-calibration by shorting the test leads. The meter uses a standard 2×16 character LCD for display.
PIC based LC meter
Rajkumar Sharma has shared his 12W Audio Amplifier project on Electronics-Lab. It is a low frequency class AB audio amplifier built around TDA2006, which provides 12W output to a 4Ω load at ±12V power supply.
12W Audio Amplifier
Drawbots are a lot of fun to build. Here is an Instructable for building a mechanical artbot using a basic circuit involving a battery and a DC motor. The project uses a four-bar linkage mechanism added to the motor to change its motion in a special way to create some fun arts.
Mechanical artbot
MikroElektronika has announced a close cooperation with FTDI Chip to develop a series of compilers and hardware development boards for FTDI’s FT90X series of microcontrollers.
1st October 2014 – Belgrade-headquartered development tool chain supplier MikroElektronika has signed a formal agreement with FTDI Chip to create mikroC, mikroBasic and mikroPascal compilers for the FT90X 32-bit microcontroller offering. The FT90X utilises a proprietary 32-bit RISC architecture – allowing it to set performance benchmarks beyond 2.93DMIPS/MHz, with true zero wait-states operation up to 100MHz frequencies, as well as capacious memory and an array of advanced connectivity resources.
MikroElektronika develops compilers for FTDI new MCUs
Gilchrist’s PIP Arduino browser is an on-going project to develop a very basic and functional web browser that runs on Arduino Uno. The current version can download and render plain HTML and follow embedded links. Users can page through the hyperlinks with the help of a joystick. The project uses a 320×240 TFT LCD screen for output.
PIP Arduino browser
Single-sided PCBs are relatively easier to homebrew. Holes for PTH components can be drilled with a reasonable accuracy without any sort of visual aid. However, if you want to make double-sided PCBs with strict drilling requirements, eyeballing might not be enough to drill holes at precise locations. This Instructable is about making a USB microscope guided PCB drill to achieve better accuracy in drilling holes in PCBs. Unlike regular drills, this machine drills holes from bottom to top.
PCB drill with USB microscope as visual aid
Jesus Echavarria has tipped us off about his RPi board, which is focused to learn Python with the Raspberry Pi board. The board easily fits on the GPIO headers of Raspberry Pi, and contains basic electronic components like LEDs, tact switches, buzzer, header for 2×16 and LCD display, to get going with basic Python programming.
RPi Board
TI’s MSP430 family of MCUs are low-power and RISC-based powerful mixed-signal processors that require a Flash Emulator Tool (FET) for in-system programming. The official MSP430 FET from TI costs about $100. Vincete describes a way to construct a MSP430 FET using TI’s popular and in-expensive Launchpad board.
MSP430 FET using TI Launchpad
[via]
Microchip Technology Inc., a leading provider of microcontroller, mixed-signal, analog and Flash-IP solutions, today announced the availability of MPLAB® Harmony Version 1.0. MPLAB Harmony is a flexible, abstracted, fully integrated firmware development platform for all 32-bit PIC32 microcontrollers (MCUs). It takes key elements of modular and object-oriented design, adds in the flexibility to use a RTOS or work without one, and provides a framework of software modules that are easy to use, configurable for specific design requirements and that are purpose built to work together. The new features in this release include the MPLAB Harmony Configurator for quick and easy driver and middleware settings management, a fully compatible, professional graphics library and many significant functional and performance improvements across many of the Harmony driver libraries. Additional enhancements have been made to existing middleware such as IPv6 certification of the Microchip TCP/IP stack.
MPLAB Harmony supports all PIC32
Designing a digital voice recorder requires sampling the audio channel, compress and decompress the signal, and store and retrieve the samples. Silicon Labs provides a reference for designing a digital voice recorder using their C8051F411 microcontroller, which has a 12-bit ADC, and a 12-bit DAC, available on chip. The ‘F411 samples the voice signal using the ADC, compresses the sample using DPCM (Differential Pulse Code Modulation), and sends the sample to the external Flash using the SPI. Later, the microcontroller retrieves the samples from the external Flash, decompresses them, and sends them to the speaker through the DAC. This reference design can record up to 87 seconds of audio.
Voice recorder design reference
Optoisolators, also known as optocouplers or photocouplers, are a very useful component in transferring electrical signals between two circuit blocks, while providing a complete electrical isolation between the two blocks. The key advantage of using an optoisolator is it blocks high voltages and voltage transients in one block being transferred to other, so that a surge in one part of the system will not disrupt or destroy the other parts. An opto-isolator connects the two blocks with a beam of light, which is modulated by input current. In this tutorial, Dan explains the basics of optoisolators and illustrates its working principle by making one using a light-emitting diode and a light-dependent resistor.
DIY optoisolator
With the advent of new audio technologies like CDs, Ipods and MP3 players, all of those old-fashioned cassette players and amplifiers have disappeared today. One of the many features missing on those old devices is wireless music streaming. This Bluetooth Ghettoblaster project by tomatoskins describes how to convert an old-time cassette player into a wireless streaming machine.
Bluetooth Ghettoblaster
Word clocks are really cool. They tell the time using words. A neat thing about them is you can customize the display to show some personalized messages. Yes, TechKiwi’s new instructable is about making a personalized word clock gift, which displays the recipient’s name as well as some personalised messages such as birthday greetings. The project uses the Arduino Mega board as main controller and the DS3231 RTC chip for time-keeping.
Personalized word clock
Dilshan Jayakody’s new project is a digitally-controlled 2.1 channel audio amplifier based on the TDA7377 AF power amplifier and PIC18F452 microcontroller. The amplifier provides 2 × 6W + 20W audio output power, ±14dB bass and treble controls, fully configurable +35dB bass booster for sub-woofer and satellite speakers and loudness switch.
DIY 2.1 channel audio amplifier
This GSM remote control project uses an AVR micro-controller (ATtiny2313) and the GM-47 GSM module to perform ON/OFF switching of remotely located devices through text message. It features four relay switches and eight digital inputs to monitor status of normal or reed switches. The SMS commands are password-protected.
SMS remote control
WebRadio is an inexpensive web radio player designed by Vassilis Serasidis using the Arduino platform. It features high-quality stereo output and 14 pre-defined radio stations, which can be set/modified in the Arduino sketch.
Arduino WebRadio player
The Arduino sends a request to a WebRadio server through the ethernet module (ENC28J60). The ENC28J60 is connected to the webradio server, sends the request and waits for response from the server. The response will be the header information of the radio station followed by the audio stream (mp3, aac etc). The arduino gets the answer from the server and sends the received data to the VS1053B mp3, aac, wma decoder. The VS1053B automatically recognizes the kind of the received format, decodes it and outputs it to the speakers. On LCD is appeared the WebRadio station number (1-14) and the first 122 characters of the server header response.
If your next Arduino project needs some kind of remote switching control, this DIY 433MHz RF receiver plus relay shield might be useful for you. It includes a 433.92Mhz RF receiver and four SPDT relays, which allows you to perform wireless control of the devices connected to the relays. Each relay is capable of switching up to 10A @ 250VAC mains power supply.
433MHz RF and relay shield
Ajoy Raman’s new project on Instructable is about making a low-cost hand-held tweezers to meause R, L, C, and Z (complex impedance). The project uses the TI’s TMS320F28027 micro-controller, an 8-port-analog-switch ADG714 from Analog Devices and the MCP6022 rail-to-rail dual Opamp IC. The ZLRC measurements are sent to a PC through an USB port using an USB-to-TTL converter. He also developed a GUI application for the PC end to display the results.
USB tweezers for ZRLC measurements
This fully-open digital wrist watch is designed by a group of employees at CERN as a special present for one of their retiring colleagues who likes hiking and timing. The watch features multiple sensor units including GPS, pressure sensor, 3D-accelerometer, compass, and ambient light sensor. A 128×128 pixels LCD with backlight feature is used for front display. The watch also provides a MicroSD card slot for storage. Powered by a 500 mAh Lithium-ion battery, the project uses Silicon Labs’ EFM32 Giant Gecko ARM® Cortex®-M3 based 32-bit microcontroller as its brain.
F*watch: Open-source wrist watch
[via: HackAday]
If you like gardening but hate to keep up with the daily routines of watering the plants, you might be interested in this Arduino controlled gardening assistant, which monitors and controls the soil humidity and lighting level inside an indoor garden to ensure that the plants have favorable conditions for healthy growth.
Indoor garden automation
