ROTARY O Click

How does it work?

Rotary O Click is based on two 74HC595 SPI-configurable 8-bit shift registers from Texas Instruments. Combined with a high-quality rotary encoder, the EC12D1564402 allows you to add a precision input knob to your design. The EC12D1564402 incremental rotary encoder is surrounded by a ring of 16 orange LEDs where a single rotation is divided into 15 discrete steps (in contrast to a potentiometer, a rotary encoder can be spun around continuously). This Click board™ is an ideal solution for building various HMI applications where precise input is required, but also for some interesting visual effects to any application.

As mentioned, this Click board™ uses the EC12D1564402, a 15-pulse incremental rotary encoder with a push-button, from ALPS. This encoder has unique mechanical specifications (debouncing time for its internal switches goes down to 2ms) and can withstand many switching cycles, up to 30.000. The supporting debouncing circuitry allows contacts to settle before the output is triggered fully.

The 74HC595 controls each LED individually positioned in a ring around the encoder through a standard SPI interface with a maximum frequency of 5MHz. Rotating the encoder, it outputs A and B signals (out of phase to each other) on the two mikroBUS™ lines, AN and PWM pins of the mikroBUS™ socket, alongside the push-button contact, which outputs through the interrupt line of the mikroBUS™ socket. The 74HC595 also has a Reset feature used across the RST mikroBUS™ line. Finally, the Rotary O Click uses the 74LVC1T45, a single-bit, dual-power supply translating transceiver with three state outputs from Diodes Incorporated for rotary encoder voltage logic translation.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on ROTARY O Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Encoder Output B	AN	1	AN	PWM	16	PWM	Encode Output A
Reset	RST	2	RST	INT	15	INT	Knob Detection
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

ROTARY O Click electrical specifications

Software Support

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

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for ROTARY O Click driver.

Key functions

• rotaryo_generic_transfer ROTARY O data transfer function.

• rotaryo_turn_on_led_by_data Function turn on led by data.

• rotaryo_turn_on_led_by_position Function turn on led by position

Example Description

The demo application controls led on click with rotory on board

 void application_task ( void ) { 
     rotaryo_turn_on_led_by_data( &rotaryo, led_data ); 

 //     Push button 
     if ( rotaryo_button_push( &rotaryo ) ) { 
         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++ ) { 
                     rotaryo_turn_on_led_by_data( &rotaryo, 0xAAAA ); 
                     Delay_ms( 100 ); 
                     rotaryo_turn_on_led_by_data( &rotaryo, 0x5555 ); 
                     Delay_ms( 100 ); 
                 } 

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

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

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

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.RotaryO

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. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.