knob

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Knob click

Knob click features a combination of high-quality quadrature rotary encoder, and a LED ring composed of 24 individual green LEDs.

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Click library

• Author : Katarina Perendic
• Date : okt 2019.
• Type : I2C type

Software Support

We provide a library for the Knob Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for Knob Click driver.

Standard key functions :

• Config Object Initialization function.

void knob_cfg_setup ( knob_cfg_t *cfg );

• Initialization function.

KNOB_RETVAL knob_init ( knob_t *ctx, knob_cfg_t *cfg );

• Click Default Configuration function.

void knob_default_cfg ( knob_t *ctx );

Example key functions :

• Functions for get Encoder position

void knob_get_encoder_position ( knob_t *ctx, int32_t *position, uint8_t *dir );

• Functions for set led state(PWM on the LED)

void knob_set_led_state ( knob_t *ctx, uint8_t led, uint8_t state );

• Functions for get SW pin(switch button) state

uint8_t knob_get_sw_button_state( knob_t *ctx );

Examples Description

The demo application displays different types of LED controls and encoder position readings.

The demo application is composed of two sections :

Application Init

Configuring clicks and log objects. Settings the click in the default configuration.

void application_init ( void )
{
    log_cfg_t log_cfg;
    knob_cfg_t cfg;

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    knob_cfg_setup( &cfg );
    KNOB_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    knob_init( &knob, &cfg );

    knob_reset( &knob );
    Delay_ms ( 300 );

    knob_default_cfg( &knob );
}

Application Task

The Task application has 3 test modes:

• The first example is setting BRIGHTNESS on all LEDs.
• Other examples put the LED in the position read from the encoder.
• The third example sets the LED to be read while the encoder registers the clockwise movement and turn off those LEDs that the encoder reads when moving in a counterclockwise direction.
• The example is changed by pressing the SW button

void application_task ( void )
{
    uint8_t cnt;
    uint8_t direction;

    //  Task implementation.

    knob_get_encoder_position( &knob, &new_position, &direction );

    if ( knob_get_sw_button_state( &knob ) == 0 )
    {
        sw_state++;
        if ( sw_state >= 3 ) sw_state = 0;

        knob_set_brightness( &knob, KNOB_BRIGHTNESS_ALL_LED, 0x00 );
        Delay_ms ( 300 );
    }

    // Logs position

    if ( new_position != old_position )
    {
        log_printf( &logger, "** EnCoder position : %d ", new_position );
    }
    old_position = new_position;

    switch ( sw_state )
    {
        // Brightness

        case 0:
        {
            cnt++;
            if ( cnt > 127 )
            {
                cnt = 0;
            }
            knob_set_brightness( &knob, KNOB_BRIGHTNESS_ALL_LED, cnt );
            Delay_ms ( 15 );

            break;
        }

        // Encoder with one led

        case 1:
        {
            if ( new_position > 24 )
            {
                knob_set_encoder_start_position( &knob, 1 );
            }
            if ( new_position < 1 )
            {
                knob_set_encoder_start_position( &knob, 24 );
            }

            if (direction == 1)
            {
                knob_set_led_state( &knob, new_position, KNOB_LED_ON );
                knob_set_led_state( &knob, new_position - 1, KNOB_LED_OFF );
            }
            else
            {
                knob_set_led_state( &knob, new_position, KNOB_LED_ON );
                knob_set_led_state( &knob, new_position + 1, KNOB_LED_OFF );
            }
            Delay_1ms();
            break;
        }

        // Encoder with all led

        case 2:
        {
            if ( new_position > 24 )
            {
                knob_set_encoder_start_position( &knob, 1 );
            }
            if ( new_position < 1 )
            {
                knob_set_encoder_start_position( &knob, 24 );
            }

            if ( direction == 1 )
            {
                knob_set_led_state( &knob, new_position, KNOB_LED_ON );
            }
            else
            {
                knob_set_led_state( &knob, new_position + 1, KNOB_LED_OFF);
            }
            Delay_1ms();
            break;
        }
    }
}

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Knob

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all Mikroelektronika compilers, or any other terminal application of your choice, can be used to read the message.

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