DIGI POT 11 Click

How does it work?

DIGI POT 11 Click as its foundation uses a double pack of the MAX5387, a dual volatile, low-voltage linear taper digital potentiometer from Analog Devices, with which four digitally controlled potentiometers are realized with end-to-end resistance values of 50kΩ. The potentiometers consist of 255 fixed resistors in series between appropriate H and L terminals, providing a low 35ppm/ºC end-to-end temperature coefficient. The potentiometer wiper (W) terminals are programmable to access any one of the 256 tap points on the resistor string.

This Click board™ communicates with MCU using the standard I2C 2-Wire interface with a maximum clock frequency of 400kHz. The potentiometers are programmable independently of each other. The MAX5387 has a 7-bit slave address with the first five MSBs fixed to 01010. The address pins A0 and A1 of both potentiometers are programmed by the user and determine the value of the last three LSBs of the slave address, which can be selected by positioning onboard SMD jumpers labeled as ADDR SEL, in U1 or U2 part, to an appropriate position marked as 0 or 1.

The I2C interface contains a shift register that decodes the command and addresses bytes, routing the data to the appropriate control registers. Data written to a control register immediately updates the wiper position. In the beginning, wipers A and B always power up in mid-position.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing 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 DIGI POT 11 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
	NC	2	RST	INT	15	NC
	NC	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

DIGI POT 11 Click electrical specifications

Software Support

We provide a library for the DIGI POT 11 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 DIGI POT 11 Click driver.

Key functions

• digipot11_set_u1_wiper This function sets the position of the selected wiper of U1 device by using I2C serial interface.

• digipot11_set_u2_wiper This function sets the position of the selected wiper of U2 device by using I2C serial interface.

Example Description

This example demonstrates the use of DIGI POT 11 Click board™ by changing the wipers position of both U1 and U2 devices.

void application_task ( void ) 
 { 
     for ( uint16_t wiper_pos = DIGIPOT11_WIPER_ZERO_SCALE; wiper_pos <= DIGIPOT11_WIPER_FULL_SCALE; wiper_pos += 5 ) 
     { 
         if ( DIGIPOT11_OK == digipot11_set_u1_wiper ( &digipot11, DIGIPOT11_WIPER_SEL_BOTH, ( uint8_t ) wiper_pos ) ) 
         { 
             log_printf( &logger, " U1 wipers position: %urn", wiper_pos ); 
         } 
         if ( DIGIPOT11_OK == digipot11_set_u2_wiper ( &digipot11, DIGIPOT11_WIPER_SEL_BOTH,  
                                                       ( uint8_t ) ( DIGIPOT11_WIPER_FULL_SCALE - wiper_pos ) ) ) 
         { 
             log_printf( &logger, " U2 wipers position: %urnn", ( DIGIPOT11_WIPER_FULL_SCALE - wiper_pos ) ); 
         } 
         Delay_ms( 1000 ); 
     } 
 }

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.DIGIPOT11

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 MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika 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.