DIGI POT 6 Click

How does it work?

DIGI POT 6 Click as its foundation uses the MCP41HV51, 8-bit dual power rails digital potentiometer with SPI serial interface and volatile memory from Microchip. It has a wide operating voltage range, analog from 10 to 36V and digital from 2.7 to 5.5V or implemented as dual-rail (±18V) for systems requiring wide signal swing or high power-supply voltages. It supports resistor configurations of 255 resistors and 256 steps and high terminal/wiper current, including the ability to sink/source up to 25mA on all terminal pins for driving larger loads.

The resistor network of the MCP41HV51 has an 8-bit resolution where each resistor network allows Zero-Scale to Full-Scale connections. All these features combined with an extended temperature range make the MCP41HV51 well suited for a broad range of high-voltage and high-temperature applications, including those in the industrial, automotive, and audio markets.

DIGI POT 6 click communicates with MCU using the SPI serial interface with a maximum frequency of 10MHz and supports the two most common SPI modes, 0 and 3. This Click board™ also has three terminals labeled as P0A, P0B, and P0W, with an internal architecture that comprises various resistances and switches. The resistance between terminals A and B, RAB, commonly called the “end-to-end” resistance, provides RAB resistance options up to 100 kΩ. In contrast, the wiper terminal, P0W, is digitally programmable to access any 2n tap points on the resistor string.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to properly use the SPI communication lines. 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 DIGI POT 6 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
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

DIGI POT 6 Click electrical specifications

Software Support

We provide a library for the DIGI POT 6 Click on our LibStock page, as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Library Description

The library covers necessary functions that enable the usage of the DIGI POT 6 Click board™. User can read and write data to and from Volatile Wiper 0 and Volatile TCON Register or issue increment and decrement commands to Volatile Wiper 0. User can also Connect/Disconnect Resistor 0 Terminal A, Resistor 0 Terminal B, Resistor 0 Wiper and Resistor 0 Hardware Configuration Control.

Key functions:

• void digipot6_write_data ( uint8_t reg_adr, uint8_t wr_byte ) – Function is used to write single byte of data into user defined register.
• uint8_t digipot6_read_data ( uint8_t reg_adr ); – Function is used to read single byte of data from user defined register.
• void digipot6_set_r0hw ( uint8_t state ); – Function is used to force Resistor 0 into the “shutdown” configuration.

Examples description

The application is composed of three sections :

• System Initialization – Initializes SPI module and LOG structures.
• Application Initialization – Initalizes SPI and device drivers, wakes up the device and connects terminal A, terminal B and wiper to the resistor 0 network.
• Application Task – Demonstrates use of DIGI POT 6 Click board™ by setting wiper to step 0, then going through the steps, fifteen at a time and displaying data via USART terminal.

void application_task ( )
{
    digipot6_write_data( DIGIPOT6_VOLATILE_WIPER_0, 0x00 );
    for ( cnt = 0; cnt <= 255; cnt += 15 )
    {
        digipot6_write_data( DIGIPOT6_VOLATILE_WIPER_0, cnt );
        Delay_ms( 10 );
        wiper_val = digipot6_read_data( DIGIPOT6_VOLATILE_WIPER_0 );
        ByteToStr( wiper_val, log_txt );
        mikrobus_logWrite( " Wiper step : ", _LOG_TEXT );
        Ltrim( log_txt );
        mikrobus_logWrite( log_txt, _LOG_LINE );
        Delay_ms( 1000 );
    }

    mikrobus_logWrite( "------------------------", _LOG_LINE );
    Delay_ms( 1000 );
}

The full application code, and ready to use projects can be found on our LibStock page.

Other mikroE Libraries used in the example:

• SPI
• UART
• Conversions

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.

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.