Project overview¶

Audio latency is a key factor in determining the quality of the user experience in communication services. A controlled delay is necessary for responsive and natural communication as it helps mitigate problems such as echo, timing issues, or a fragmented user experience.

The aim of this project is to provide a hardware and software test framework for measurement and characterization of audio latencies.

The test framework includes:

• Audio latency tester board - responsible for synchronized emitting sound with a speaker and collecting audio samples (in various sampling rates) from a pair of microphones

• Microphone board - houses a PDM microphone with selectable left or right channel audio output

• Audio latency tester software - provides firmware for the RP2040 MCUs located on the Audio latency tester board, as well as host PC application responsible for collecting, sending and automatically analyzing audio samples

• Speaker

Test framework architecture¶

The system integrates two microphones, an audio codec, an audio power amplifier and a speaker. These peripherals are driven with two separate RP2040 MCU units, one for playback and one for recording, that can synchronize timebase via a shared GPIO signal.

The system architecture is presented below: