POT 4 Click

How does it work?

POT 4 Click is based on the PRS11R-425F-S103B1, a high-quality rotary 10k potentiometer from Bourns providing very accurate voltage output. The PDB081-P10-103B1 features a small form factor, offers a push-on momentary switch, a flatted shaft style, and a wide operating temperature range, withstanding 50V maximum voltage. Its typical applications include consumer white goods, test and measurement equipment, communications and laboratory equipment, and other applications requiring an analog or digitized control voltage.

The output of the potentiometer is brought to the non-inverting input of the OPA344, a rail-to-rail operational amplifier from Texas Instruments, used as a stable unity gain buffer, providing a constant input and output impedance. Without a buffer, the variable impedance would affect the reference voltage. Therefore, the OPA344 ensures good stability of the circuit.

A buffered signal can be converted to a digital value using MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip using a 2-wire I2C compatible interface, or can be sent directly to an analog pin of the mikroBUS™ socket labeled as AN. The selection can be performed by using an onboard SMD switch labeled as VIN SEL, placing it in an appropriate position marked as AN or ADC. Bearing that the PRS11R-425F-S103B1 has an optional push momentary switch, this Click board™ also has an interrupt that will signal to users when this feature is used.

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 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 POT 4 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog Signal	AN	1	AN	PWM	16	NC
	NC	2	RST	INT	15	SW	Switch Interrupt
	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	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

POT 4 Click electrical specifications

Software Support

We provide a library for the POT 4 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 POT 4 Click driver.

Key functions

• pot4_get_switch_pin This function returns the switch (SW) pin logic state.

• pot4_read_voltage This function reads raw ADC value and converts it to proportional voltage level.

• pot4_convert_voltage_to_percents This function converts analog voltage to potentiometer position in percents.

Example Description

This example demonstrates the use of POT 4 Click board™ by reading and displaying the potentiometer position.

 void application_task ( void ) 
 { 
     if ( !pot4_get_switch_pin ( &pot4 ) ) 
     { 
         float voltage = 0; 
         if ( POT4_OK == pot4_read_voltage ( &pot4, &voltage ) )  
         { 
             log_printf( &logger, " AN Voltage : %.3f Vrn", voltage ); 
             log_printf( &logger, " Potentiometer : %u %%rnn",  
                         ( uint16_t ) pot4_convert_voltage_to_percents ( &pot4, voltage ) ); 
             Delay_ms( 1000 ); 
         } 
     } 
 }

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.POT4

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.