Rhino Speech-to-Intent
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.

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 Rhino_EN package, and click on the Install button.

Usage

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

#include <Rhino_EN.h>

#define MEMORY_BUFFER_SIZE ${MEMORY_BUFFER_SIZE}
static const char* ACCESS_KEY = "${ACCESS_KEY}";

uint8_t memory_buffer[MEMORY_BUFFER_SIZE] __attribute__((aligned(16)));

const uint8_t context_array[] = ${CONTEXT_ARRAY};

const float sensitivity = 0.5f;
const float endpoint_duration_sec = 1.0f;
const bool require_endpoint = true;

pv_rhino_t *rhino = NULL;

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

   status = pv_rhino_init(
        ACCESS_KEY,
        memory_buffer,
        MEMORY_BUFFER_SIZE,
        context_array,
        sizeof(context_array),
        sensitivity,
        endpoint_duration_sec,
        require_endpoint,
        &rhino);

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

Get the audio frames and pass them in to pv_rhino_process in the loop function:

void loop() {
    const int16_t *buffer = pv_audio_rec_get_new_buffer();
    if (buffer) {
        bool is_finalized = false;
        const pv_status_t status = pv_rhino_process(rhino, buffer, &is_finalized);
        if (status != PV_STATUS_SUCCESS) {
            // handle error logic
            while(1);
        }
        if (is_finalized) {
            // inference event logic/callback
        }
    }
}

Release resources explicitly when done with Rhino:

pv_rhino_delete(rhino);

Custom Contexts

1. Obtain the UUID of the chipset:
   1. Open File -> Examples -> Rhino_EN -> GetUUID.
   2. Click Upload and check the Serial Monitor for the UUID of the board:

UUID:  xx xx xx xx xx xx xx xx

2. Go to Picovoice Console to create models for Rhino Speech-to-Intent engine..
3. Select Arm Cortex-M as the platform when training the model.
4. Select appropriate board type and paste in your board UUID.
5. Train your models.
6. Download your custom context model.
7. Decompress the zip file. The .rhn file inside is the binary model for the Rhino context. The zip archive also contains a .h header file containing the C array version of the binary model.
8. Copy the contents of the array inside the .h header file and update the context_array:

const uint8_t context_array[] = ${CUSTOM_CONTEXT_ARRAY};

Non-English Languages

Open the Library Manager in the Arduino IDE and search for Rhino. Click Install on the language desired and add the header file to the project:

#include <Rhino_{$LANGUAGE_CODE}>

Demo

For the Rhino Speech-to-Intent Arduino SDK, we offer demo projects for several evaluation boards to demonstrate how to use the Rhino engine on Arduino.

Setup

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

Usage

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

Resources