ROTARY B Click

Rotary B Click carries a 15-pulse incremental rotary encoder with detents, surrounded by a ring of 16 blue LEDs. It’s a perfect solution for adding a precision input knob to your design. The encoder outputs A and B signals (out of phase to each other); the knob also acts as a push-button which sends an interrupt to the target board MCU. The LED ring is controlled through SPI lines (CS, SCK, MISO, MOSI). Rotary Click™ can be used with either a 3.3V or 5V power supply.

Click Product page

Click library

• Author : Stefan Ilic
• Date : Jun 2021.
• Type : SPI type

Software Support

We provide a library for the RotaryB 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 from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for RotaryB Click driver.

Standard key functions :

• rotaryb_cfg_setup Config Object Initialization function.

  void rotaryb_cfg_setup ( rotaryb_cfg_t *cfg );

• rotaryb_init Initialization function.

  ROTARYB_RETVAL rotaryb_init ( rotaryb_t *ctx, rotaryb_cfg_t *cfg );

Example key functions :

• rotaryb_generic_transfer ROTARY B data transfer function.

  void rotaryb_generic_transfer ( rotaryb_t *ctx, uint8_t *wr_buf, uint16_t wr_len, uint8_t *rd_buf, uint16_t rd_len );

• rotaryb_turn_on_led_by_data Function turn on led by data.

  void rotaryb_turn_on_led_by_data ( rotaryb_t *ctx, uint16_t write_data );

• rotaryb_button_push Function return 1 if button is pushed and return 0 if not

  uint8_t rotaryb_button_push ( rotaryb_t *ctx );

Example Description

The demo application controls led on Click with rotary on board.

The demo application is composed of two sections :

Application Init

Initializes SPI driver, set initial states, set RST logic high and performs device configuration.

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    rotaryb_cfg_t rotaryb_cfg;  /**< Click config object. */

    /** 
     * 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.

    rotaryb_cfg_setup( &rotaryb_cfg );
    ROTARYB_MAP_MIKROBUS( rotaryb_cfg, MIKROBUS_1 );
    err_t init_flag  = rotaryb_init( &rotaryb, &rotaryb_cfg );
    if ( init_flag == SPI_MASTER_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_info( &logger, " Application Task " );

    led_data = 0x0001;
    old_state = 0;
    new_state = 1;
    old__rot_state = 0;
    new_rotate_state = 1;
}

Application Task

Show functionality of Rotary_R Click, rotating and turn on/off led's, using the SPI interface.

void application_task ( void ) {
    rotaryb_turn_on_led_by_data( &rotaryb, led_data );

//     Push button
    if ( rotaryb_button_push( &rotaryb ) ) {
        new_state = 1;
        if ( new_state == 1 && old_state == 0 ) {
            old_state = 1;
            led_state = ( led_state + 1 ) % 5;
            if ( led_state == 4 ) {
                for ( old_state = 0; old_state < 17; old_state++ ) {
                    rotaryb_turn_on_led_by_data( &rotaryb, 0xAAAA );
                    Delay_ms ( 100 );
                    rotaryb_turn_on_led_by_data( &rotaryb, 0x5555 );
                    Delay_ms ( 100 );
                }

                for ( old_state = 0; old_state < 17; old_state++ ) {
                    rotaryb_turn_on_led_by_position( &rotaryb, old_state );
                    Delay_ms ( 100 );
                }

                led_state = 0;
                led_data = rotaryb_get_led_data( led_state );
            }
            else {
                led_data = rotaryb_get_led_data( led_state );
            }
        }
    }
    else {
        old_state = 0;
    }

//     Rotate Clockwise and CounterClockwise
    if ( rotaryb_get_eca_state( &rotaryb ) == rotaryb_get_ecb_state( &rotaryb ) ) {
        old__rot_state = 0;
        start_status = rotaryb_get_eca_state( &rotaryb ) && rotaryb_get_ecb_state( &rotaryb );
    }
    else {
        new_rotate_state = 1;
        if ( new_rotate_state != old__rot_state ) {
            old__rot_state = 1;
            if ( start_status != rotaryb_get_eca_state( &rotaryb ) ) {
                led_data = ( led_data << 1 ) | ( led_data >> 15 );
            }
            else {
                led_data = ( led_data >> 1 ) | ( led_data << 15 );
            }
        }
    }
}

Note

In orther to use all of the clicks functionality, pull down INT pin.

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.RotaryB

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.