A Soundcard HAT for the Raspberry Pi

If you have been wondering how to use the popular Raspberry Pi (RBPi) single board computer for effects to be used with musical instruments such as the guitar, the Pisound board from Blokas may be the answer. With the Pisound board, any musician can connect any type of audio gear to the RBPi, and bring their project to an entirely new level. Pisound is a soundcard HAT for the RBPi.

HAT is an acronym for Hardware Attached on Top of an RBPi. HAT boards have an EEPROM that tells the RBPi the values of its variables specific to the device on the board. The HAT board will also have a GPIO connector to match with that on the RBPi, so that when plugged in, the HAT will sit atop the RBPi.

The Pisound HAT for the RBPi3 acts as a high-technology sound card. Not only does it allow sending and receiving audio signals from its jacks, but it can also send MIDI input and output signals to compatible devices. On board the card are two 6 mm input and output jacks, two standard DIN-5 MIDI input/output sockets, potentiometers for gain and volume, and a button for activating patches of manipulating audio. The Indiegogo campaign has given the Pisound board an incredibly successful start.

The Pisound website offers excellent documentation, making it a simple affair to set up the board. First, you have to mount the board atop your RBPi, matching the GPIO pins, and securing it with screws. Next, download and install a fresh installation of the Raspbian OS and set up the software according to instructions from the website. The only thing that remains now is to connect the instrument and create patches for Pure Data. This is a popular visual programming interface to manipulate media streams.

The possibilities with Pisound are endless. For instance, you can create simple fuzz, delay, and tremolo guitar effects. Limited only by your imagination, you could come up with endless ideas.

For example, the guitar effects could go into a web interface, accessible over a local network on a tablet or smartphone. On the other hand, with the characteristics of the guitar signals, you could control an interactive light show or project visualization on the stage. One of the advantages of the Pisound is you can use the audio input stream basically to generate other non-audio activities.

The compact and practical size of the project makes it convenient for embedding it within one of your instruments say the guitar. However, it is always possible to design and fabricate a custom enclosure for the board and the RBPi.

Sonic Pi, a musical community favorite, has also pledged to support the board very soon. That means even if you do not own a musical instrument, or play one, you can still make awesome sound effects with this clever little HAT.

You can load patches from Pure Data using a USB key. The button on the card makes it easier to interface with the RBPi. Moreover, it you are familiar with Automatonism, it will be easier for playing with the Pisound just as if it were a modular synthesizer.