ESP-IDF Notecard Component

An ESP-IDF component for integrating Espressif devices with the Blues Notecard. This component provides a thread-safe interface to the Notecard using the note-c library.

Installation

idf.py add-dependency "blues/notecard"

Usage

The component can be used to communicate with the Notecard using I2C or UART. The GPIO pins can either be set within application code or via menuconfig.

Basic Example

#include "notecard.h"

void app_main(void) {
    // Initialize with default I2C configuration
    notecard_config_t config = NOTECARD_I2C_CONFIG_DEFAULT();
    // or with UART
    // notecard_config_t config = NOTECARD_UART_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(notecard_init(&config));

    // Send a request using note-c API
    J *req = NoteNewRequest("hub.set");
    JAddStringToObject(req, "product", "com.your-company:your-product");
    JAddStringToObject(req, "mode", "continuous");
    if (!NoteRequest(req)) {
        ESP_LOGE("app", "hub.set failed");
    }
}

Configuration

The component can be further configured with menuconfig.

idf.py menuconfig
Component config  --->  Notecard Configuration

Thread Safety

The component automatically provides thread-safe access to the Notecard in multi-threaded FreeRTOS applications. The underlying note-c library protects the Notecard from concurrent access using internal mutexes, so no additional locking is required for normal use.

I2C Bus Sharing

If you have other I2C peripherals on the same bus as the Notecard, register your I2C mutex with note-c using NoteSetFnI2CMutex() to minimize the time spent under lock.

For your convenience, we have provided a default implementation of I2C mutex APIs to coordinate access (example shown below):

#include "notecard.h"

// Access your I2C peripherals
notecard_i2c_lock();
i2c_master_transmit(my_peripheral_handle, data, len, timeout);
notecard_i2c_unlock();

This ensures the note-c won't attempt I2C communication while you're accessing your other peripherals.

In order to enable/disable the provided I2C bus mutex (e.g. when using your own mutex), use menuconfig:

Component config  --->  Notecard Configuration  --->  Default I2C Configuration  --->  [ ] Enable I2C mutex

Note: The I2C mutex is enabled by default.

Examples

For examples, see the examples directory.

Examples are designed to run on:

• Adafruit ESP32 Feather V2
• Notecard
• Notecarrier F

If you wish to use a different ESP32 board (or different ESP32 chip), you will need to adjust the GPIO pins used for the Notecard. See the Kconfig file for the default I2C and UART GPIO pins.

Documentation

For more information, visit Blues Developer Documentation.