techn0man1ac@ instructables.com build a nice VU meter using Arduino and an OLED display.
Hello, instructable. Today I will tell you how to make a simple digital VU meter (sound level meter) using Arduino and OLED displays and 2 resistors by yourself (DIY). The device is quite simple, for beginners it will be a rewarding experience.
pisound is an ultra-low latency high-quality soundcard and MIDI interface specially designed for Raspberry Pi pocket computers. Equipped with 192kHz 24-bit Stereo Input and Output driven by the legendary Burr-Brown chips, DIN-5 MIDI Input and Output ports, user-customizable button and bundled software tools, this little board will bring your audio projects to a whole new level!
The electronics engineer and microcontroller programmer expert, Masih Vahida has launched his latest SoundDuino Arduino shield product: SoundDuino 3!
SoundDuino is a WAV Sound Player & Recorder Shield for Arduino. This sound shield let you record and play sound files to or from a Micro-SD memory card with all libraries and samples for the Arduino IDE.
“SoundDuino is a sound recorder and player that is able to play the sound files from the Micro-SD memory card or even record sounds to the memory with your desired file name. It supports FAT16 and FAT32 and you can easily copy your files into the memory and to play them, you only need to use the library that we give you with this shield and just send the file name that you want to play! Yes, very very easy!” Vahida explains.
This video shows the very first version of SoundDuino and some of its applications
The newest shield, SoundDuino3, is based on NXP LPC2103 ARM7 32bit microcontroller and it can play 16 bit 48khz sound files with a very high quality. It also has audio input and output jacks, an onboard microphone as well and can work from 3.3v to 5v. SoundDuino fits nicely on an Arduino Uno and is compatible with any Arduino boards using pins GND, VCC, RX and TX. Moreover, the device is delivered with libraries and examples for Arduino IDE.
This project is now live on Kickstarter, check the campaign video
You can use this shield to announce numbers and add you own files into the memory. You can also extend the example code and have it read the text also.
SoundDuino 3 specifications:
Updated firmware, high quality audio
Automatic baudrate detection
Sound quality is Stereo 16 bit 48hkz (SoundDuino 1 was Mono 8 bit 48khz)
Super easy to use, new functions in library to announce the numbers .
More useful functions in the library
the sound quality is much much better than the last version
System voltage is 3.3v compatible with Arduino boards
With SoundDuino shield it seems easier to start building some great audio projects. You can follow the project updates and order your own SoundDuino 3 for $59 now from the crowdfunding campaign.
Audio projects become smaller over time with the rapid advancement of technology. A traditional power supply is still considered large compared to audio projects size constraints and it may not fit such delicate applications that need to deliver a good sound with zero noise.
Jan Didden, audio specialist who is known for his own publications Linear Audio, has came up with a new idea that can help in perfecting audio projects. The SilentSwitcher is a 55 x 31 mm special power supply module designed to supply clean power to high-end analog and digital audio circuits.
“One goal of this power supply that it doesn’t need to connect to the mains, you can use it with a USB charger or with a power bank… All problems with ground loops and mains born noise are not existing”- Jan Didden, the designer of The SilentSwitcher
The SilentSwitcher uses a combination of switching and linear regulators to generate a stable and noise-free supply voltage. The module can be powered from a 5V USB adapter, or from a 5V power bank for complete isolation. It delivers ±150 mA and a choice of 6V, 5V or 3.3V at 0.5 A to benefit most of your applications. The absolute maximum input voltage is 12VDC but in normal operation it is preferable to limit it to 10VDC.
Outputs (analog): +15 and -15 VDC at 150mA* each;
Output (6/5/3.3V): selectable 6, 5 or 3.3 VDC at 0.5A*;
Output noise (6/5/3.3V): less than 1mV broadband
Output impedance (analog): less than 10mΩ (+15V) and 80mΩ (-15V) at 20kHz
Output impedance (6/5/3.3V): less than 3mV drop with 100mA current step.
15V output at 150mA are provided thanks to the very low noise linear regulators of Texas InstrumentsTPS7A47, TPS7A33 that suppress all the noise from the switching regulator by a factor of one thousand even at 1 Megahertz. Such chips have driven zero noise to switcher technology and have shown incredible quiet and low noise performance.
Jan Didden talking about his product
The well designed board will help in keeping all elements quiet and avoiding excess radiation. There are 2- and 3-pin headers on the PCB to connect the load, and a 2-pin header for an On/Off switch. The connection to the 5V source is through a B-type USB connector or a standard 2-pin screw-type connector block. You can mount the PCB on the back of your enclosure with a hole cut out for the USB-B – no further input wiring required.
This power supply will be a great companion for your project! No need to think about wiring or transformers, and you won’t face any issues like mains hum or mains earth loops.
The SilentSwitcher is live on a Kickstarter crowdfunding campaign and there are only few hours left to go! You can get your own SilentSwitcher for $59 and you will receive a fully assembled and tested board.
Cezar Chirila @ allaboutcircuits.com shows how to build a Class-D amplifier which has amazing efficiency.
What is a Class-D audio power amplifier? The answer could be just a sentence long: It is a switching amplifier. But in order to fully understand how one works, I need to teach you all its nooks and crannies.
Tiny stereo audio amplifier board has been designed around SMD TDA7266D IC from ST. The TDA7266D is a dual bridge amplifier specially designed for Portable Audio, LCD TV/Monitor, PC Motherboard, and TV applications. This circuit provides high quality audio output of 3W approx. on each channel with standard audio signal input. The circuit works with 3.5V to 5V. Due to low supply input this amplifier is suitable for small size audio gadgets and portable audio applications like MP3 player, Voice messaging system, Warning signals, Annunciator etc.
Supply voltage range 3.5 to 5v (maximum supply 5v due to small pcb and small thermal area)
joesugar @ ceworkbench.wordpress.com has designed a S/PDIF Sound Card using the PCM2906 IC.
In the belief that I’d rather build than buy I decided to update one of my previous projects, a PCM2904 based sound card, to include an S/PDIF interface. The update was a cinch because TI has a pin-for-pin replacement for the PCM2904 (the PCM2906) with an S/PDIF interface. All I had to do was replace the audio jacks with fiber-optic transmitter/receivers connected to the appropriate pins.
AtomicZombie @ avrfreaks.net used an ATtiny85 ATMEL microcontroller to produce a 170×240 VGA signal and also send audio along with video.
The original plan was to just bit bang some mono VGA and do up a Pong or Tetris game, but things went MUCH MUCH further than I ever thought possible, so over the next few weeks I will detail this fun project here. I call it The QUARK-85 VGA DEMO System.
So what can one do with an ATTINY-85 and no other external components, an 8 pin package that leaves ONLY 4 IO lines after you feed it a clock??
How about 4 color rock solid VGA with stereo sound!!!