Tag Archives: Fred Pulver

ATxmega128A1U powers OpenAudioPal

OpenAudioPal – which recently made its Kickstarter debut – is an open source audio DSP development platform loaded with a number of algorithms, including feedback prevention.


According to Fred Pulver of Matrix Microsystems, the feedback prevention algorithm was originally developed to solve a microphone feedback problem in a high powered military hailing unit.

“The concept was transferred to a commercial concept and the OpenAudioPal was created with the thought that a open source development board would be a item of interest,” said Pulver.


“While there are demonstration boards for various microprocessors and for various digital signal processors, the OpenAudioPal combines components for a developer to create a complete system.”

The OpenAudioPal is powered by an Atmel ATxmega128A1U microcontroller (MCU) paired with two Analog Devices ADAU1761 Sigma DSPs. Although the platform is equipped with two audio digital signal processors, only one is used in the feedback prevention application. Meanwhile, the ATxmega128A1U is tasked with switch sensing and control, as well as storing the signal processor software which it loads at startup.

“We used the Atmel ATJTAGICE3 to program the ATXMEGA128A1U and the EVAL-ADAU1761Z to develop the ADAU1761software,” Pulver added.


“The EVAL-ADAU1761Z kit comes with a USB to I2C adapter that provides a communication link between SigmaStudio and a target board such as the OpenAudioPal.”

In terms of the enclosure, the OpenAudioPal is protected by a rubber outer boot and measures approximately 3″ x 5.7″ x 1.2″. A 9Volt battery provides approximately 50 hours under normal use.

Interested in learning more? You can check out OpenAudioPal’s official Kickstarter page here.