Tag Archives: audio

Arduino controlled Dual Mono AK4490 DAC (part 3)

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Arduino controlled Dual Mono AK4490 DAC

Here’s the part 3 of Dimitris’ Arduino controlled Dual Mono AK4490 DAC project we covered previously:

Following up on Part 2, it’s time to talk about the output stage.
This output stage is the brainchild of my friend Kostas, all I did was lay out the PCB.
It is a fully discreet single-ended class-A output stage, outputting ~2.4V RMS.

More details on Dimdim’s blog. If you missed part 1 and part 2, be sure to check it out.

Game audio for the ESP32

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ESP32 game audio at Buildlog.Net blog:

I have been working on some games for the ESP32 and needed some decent quality audio with a minimum number of additional components.  I was bouncing between using the DAC and using the I2S bus. The DAC requires less external parts, so I went that way. I ended up creating a very simple library for use in he Arduino IDE. (Note: This only works with ESP32)

Check out the video after the break.

Tinkernut’s do-it-yourself Pi Zero audio HAT

via Raspberry Pi

Why buy a Raspberry Pi Zero audio HAT when Tinkernut can show you how to make your own?

Adding Audio Output To The Raspberry Pi Zero – Tinkernut Workbench

The Raspberry Pi Zero W is an amazing miniature computer piece of technology. I want to turn it into an epic portable Spotify radio that displays visuals such as Album Art. So in this new series called “Tinkernut Workbench”, I show you step by step what it takes to build a product from the ground up.

Raspberry Pi Zero audio

Unlike their grown-up siblings, the Pi Zero and Zero W lack an onboard audio jack, but that doesn’t stop you from using them to run an audio output. Various audio HATs exist on the market, from Adafruit, Pimoroni and Pi Supply to name a few, providing easy audio output for the Zero. But where would the fun be in a Tinkernut video that shows you how to attach a HAT?

Tinkernut Pi Zero Audio

“Take this audio HAT, press it onto the header pins and, errr, done? So … how was your day?”

DIY Audio: Tinkernut style

For the first video in his Hipster Spotify Radio using a Raspberry Pi Tinkernut Workbench series, Tinkernut – real name Daniel Davis – goes through the steps of researching, prototyping and finishing his own audio HAT for his newly acquired Raspberry Pi Zero W.

The build utilises the GPIO pins on the Zero W, specifically pins #18 and #13. FYI, this hidden gem of information comes from the Adafruit Pi Zero PWM Audio guide. Before he can use #18 and #13, header pins need to be soldered. If the thought of soldering pins to the Pi is somewhat daunting, check out the Pimoroni Hammer Header.

Pimoroni Hammer Header for Raspberry Pi

You’re welcome.

Once complete, with Raspbian installed on the micro SD, and SSH enabled for remote access, he’s ready to start prototyping.

Ingredients

Tinkernut uses two 270 ohm resistors, two 150 ohm resistors, two 10μf electrolytic capacitors, two 0.01 μf polyester film capacitors, an audio jack and some wire. You’ll also need a breadboard for prototyping. For the final build, you’ll need a single row female pin header and some prototyping board, if you want to join in at home.

Tinkernut audio board Raspberry Pi Zero W

It should look like this…hopefully.

Once the prototype is working to run audio through to a cheap speaker (thanks to an edit of the config.txt file), the final board can be finished.

What’s next?

The audio board is just one step in the build.

Spotify is such an awesome music service. Raspberry Pi Zero is such an awesome ultra-mini computing device. Obviously, combining the two is something I must do!!! The idea here is to make something that’s stylish, portable, can play Spotify, and hopefully also display visuals such as album art.

Subscribe to Tinkernut’s YouTube channel to keep up to date with the build, and check out some of his other Raspberry Pi builds, such as his cheap 360 video camera, security camera and digital vintage camera.

Have you made your own Raspberry Pi HAT? Show it off in the comments below!

The post Tinkernut’s do-it-yourself Pi Zero audio HAT appeared first on Raspberry Pi.

App note: BH45F0031 Earphone jack communication

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Holtek’s App note about their audio to digital signal converter chip BH45F0031 that together with an phone app, communication via audio phone jack is possible. Link here (PDF)

The BH45F0031 is a Flash type 8-bit high performance RISC architecture microcontroller, which is designed for smart phone headset interface applications that can directly transmit data and communicate with the microcontroller using their audio earphone interface.

The BH45F0031 can convert the analog audio signals from mobile phones into digital data and transmit them to a master external MCU. The device can also convert the digital data from the master MCU into analog audio signals and transmit them to mobile phones.

100W AF dummy load

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Dilshan Jayakody has published a new build:

This is a quick post to showcase 100W 4 channel AF dummy load which we build to test the output stages of audio power amplifiers. This dummy load use 4, 8Ω 100W wire wound resistors which are available in eBay. In this unit all 4 resistors are mounted on 170mm × 40mm × 60mm high gauge aluminum heat sink.

Project info at Dilshan Jayakody’s blog.