![]() ![]() wav files from the MicroPython non-volatile flash memory or an SD card. WAV files do take more space than compressed MP3 files, but they are easier to play because the decoding steps are trivial for a microcontroller to perform. WAV files with Pulse Code Modulation Encoding in. We can also add a SD card if we need more flash memory. Our flash budget for the Raspberry Pi Pico is 2M, so we can easily store 10 sound effects in 200K or 1/10 of our available flash memory. This one-second 8K Hz WAV file will be about 20K. Our robots typically will play a short 1-second sound to tell us they are performing an action like stopping, backing up or turning. This is a good compromise between smaller size and sound fidelity in typical robots. The audio bit depth is how many bits we used to encode the amplitude of the sound.įor our labs, we will be using mono files (not stereo) a sampling rate of 8,000 samples per second (8K Hz) and a sampling rate of 16-bit depth.The downside is that the audio file takes more space. The more frequently we sample (up to 41K per second) the higher the fidelity of the recording. The Sampling Rate which is how frequently an audio signal is sampled.For this lab there are two key concepts to understand: Background on Audio EncodingĪudio files are encoded in many formats. By combining our Pico with an SD card reader we can also play many sounds and even full-length music and full albums. According to the specification of the Raspberry Pi Pico, the system comes with 2MB on-board QSPI Flash that we can use to store sound files. In this lesson we will demonstrate how to play a high-quality audio files that are stored on the two megabytes of non-volatile static memory of the Pico. Playing Sounds on The RP2040 ChipĪlthough we can play tones of various pitches on the PR2040 using the PMW to generate square waves, the quality of this sound is not close to high-fidelity sound like you would expect in a personal MP3 audio player. If you stick to pins for GPIO 2 and 3 for the two channels the test run OK. We also are having problems when different GPIO pins are used. See the wav file test results section below. ![]() ![]() The wavePlayer is in an early draft form and has unpredictable interactions with other components. Clone the Pico Audio PWM GitHub Repository ![]()
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