Cobra VAD — Arduino Quick Start

Platforms

• Arduino Nano 33 BLE Sense

Requirements

• Arduino IDE

Picovoice Account & AccessKey

Signup or Login to Picovoice Console to get your AccessKey. Make sure to keep your AccessKey secret.

Cobra VAD for MCU is currently in Beta and available for evaluation for 30 minutes per device, (i.e., user). If you are working on a commercial project or require extended access, please contact Picovoice with your project details.

Quick Start

Setup

1. Install and select desired board from Tools -> Board.
   • Install Arduino Mbed OS Nano Boards for Arduino Nano 33 BLE Sense.
2. Select the desired device Serial Port to upload package via Tools -> Port.
3. Open the Library Manager in the Arduino IDE.
4. Search for the Cobra package, and click on the Install button.

Usage

Initialize audio and construct the porcupine object in the setup function:

#include <Cobra.h>

static const char* ACCESS_KEY = "${ACCESS_KEY}";

#define MEMORY_BUFFER_SIZE ${MEMORY_BUFFER_SIZE}
uint8_t memory_buffer[MEMORY_BUFFER_SIZE] __attribute__((aligned(16)));

static const float THRESHOLD = 0.75f;

pv_cobra_t *cobra;

void setup() {
   pv_status_t status = pv_audio_init_rec();
   if (status != PV_STATUS_SUCCESS) {
      // error starting audio
      while(1);
   }

   status = pv_cobra_init(
        ACCESS_KEY,
        MEMORY_BUFFER_SIZE,
        memory_buffer,
        &cobra);

   if (status != PV_STATUS_SUCCESS) {
       // error handling logic
       while(1);
   }
}

Pass in audio to the pv_cobra_process function:

void loop() {
    const int16_t *buffer = pv_audio_rec_get_new_buffer();
    if (buffer) {
        float voice_probability;
        const pv_status_t status = pv_cobra_process(handle, buffer, &voice_probability);
        if (status != PV_STATUS_SUCCESS) {
            // handle error logic
            while(1);
        }
        if (voice_probability > THRESHOLD) {
            // inference event logic/callback
        }
    }
}

Release resources explicitly when done with Cobra Voice Activity Detection:

pv_cobra_delete(cobra);

Demo

For the Cobra Voice Activity Detection SDK, we offer demo applications that demonstrate how to use the VAD engine on real-time audio streams on Arduino.

Setup

1. Open the Library Manager in the Arduino IDE.
2. Search for the Cobra package, and click on the Install button.

Usage

1. Open File -> Examples -> Cobra -> Cobra.
2. Replace ACCESS_KEY with the AccessKey obtained from picovoice console.
3. Press Upload and check Serial Monitor for outputs.

Resources