Strive for perfection in your projects using AD5142A and TM4C129ENCPDT
Say goodbye to analog limitations
Published Nov 10, 2023
Click board™
DIGI POT 12 Click
Dev. board
Fusion for Tiva v8
Compiler
NECTO Studio
MCU
TM4C129ENCPDT
Maximize the potential of your electronic circuits by unlocking unparalleled precision with our digital potentiometer – the key to achieving peak performance and efficiency in every application.
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Hardware Overview
How does it work?
DIGI POT 12 Click is based on the AD5142A, a dual-channel, 256-position nonvolatile digital potentiometer from Analog Devices. The resistor wiper position is determined by the RDAC register contents, which act as a scratchpad register, allowing unlimited changes of resistance settings. The scratchpad register can be programmed with any position setting using the standard I2C interface by loading the 16-bit data word. The nominal resistance of the RDAC between terminals A and terminals B (RAB) is 10KΩ with 8-bit RDAC latch data decoded to select one of the 256 possible wiper settings. When a desired position is found, this value can be stored in the onboard EEPROM memory; thus, the wiper position is always restored for subsequent power-ups. The EEPROM data can be read back, written
independently, and protected by software. This Click board™ communicates with MCU through a standard 2-Wire I2C interface and operates at Standard (100KHz) and Fast (400KHz) data transfer modes. The I2C address can be selected via the ADDR SEL jumpers with 0 selected by default. There is an RST pin for resetting the digital potentiometers RDAC registers from EEPROM, with active LOW logic. In addition, this Click board™ comes with the INDEP SEL jumper that allows you to choose between the potentiometer and the linear gain setting mode, with the potentiometer mode set by default (0). The linear gain setting mode of operation can control the potentiometer as two independent rheostats connected at a single point. Once the jumper is set, it can not be turned off by software. In
addition, there is a burst mode in which multiple data bytes can be sent to the host MCU. The Shutdown mode places the RDAC in a zero power consumption while the data in EEPROM remains. There is no polarity constraint between the B, W, and A on both terminals, but they can not be higher than the VCC (5V maximum) nor lower than the VSS (0V). This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this 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.
Features overview
Development board
Fusion for TIVA v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different 32-bit ARM® Cortex®-M based MCUs from Texas Instruments, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over a WiFi network. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, Fusion for TIVA v8 provides a fluid and immersive working experience, allowing access
anywhere and under any circumstances at any time. Each part of the Fusion for TIVA v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.
Communication options such as USB-UART, USB HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. Fusion for TIVA v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Type
8th Generation
Architecture
ARM Cortex-M4
MCU Memory (KB)
1024
Silicon Vendor
Texas Instruments
Pin count
128
RAM (Bytes)
262144
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Fusion for Tiva v8 as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for DIGI POT 12 Click driver.
Key functions:
digipot12_set_resistance- DIGI POT 12 set the resistance function.digipot12_get_resistance- DIGI POT 12 get the resistance function.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief DIGI POT 12 Click example
*
* # Description
* This library contains API for DIGI POT 12 Click driver.
* The demo application uses a digital potentiometer
* to change the resistance values of both channels.
*
* The demo application is composed of two sections :
*
* ## Application Init
* The initialization of I2C module, log UART, and additional pins.
* After the driver init, the app executes a default configuration.
*
* ## Application Task
* This example demonstrates the use of the DIGI POT 12 Click board™.
* The demo application iterates through the entire wiper range and
* sets the resistance of both channels in steps of approximately 1kOhm.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "digipot12.h"
static digipot12_t digipot12;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
digipot12_cfg_t digipot12_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.
digipot12_cfg_setup( &digipot12_cfg );
DIGIPOT12_MAP_MIKROBUS( digipot12_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == digipot12_init( &digipot12, &digipot12_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( DIGIPOT12_ERROR == digipot12_default_cfg ( &digipot12 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
log_printf( &logger, " ----------------------------\r\n" );
Delay_ms ( 100 );
}
void application_task ( void )
{
static float res_kohm;
for ( uint8_t n_cnt = DIGIPOT12_RES_0_KOHM; n_cnt <= DIGIPOT12_RES_10_KOHM; n_cnt++ )
{
if ( DIGIPOT12_OK == digipot12_set_resistance( &digipot12, DIGIPOT12_WIPER_SEL_1, ( float ) n_cnt ) )
{
if ( DIGIPOT12_OK == digipot12_get_resistance( &digipot12, DIGIPOT12_WIPER_SEL_1, &res_kohm ) )
{
log_printf( &logger, " Rwb1 : %.2f kOhm\r\n", res_kohm );
Delay_ms ( 100 );
}
}
if ( DIGIPOT12_OK == digipot12_set_resistance( &digipot12, DIGIPOT12_WIPER_SEL_2, ( float ) ( DIGIPOT12_RES_10_KOHM - n_cnt ) ) )
{
if ( DIGIPOT12_OK == digipot12_get_resistance( &digipot12, DIGIPOT12_WIPER_SEL_2, &res_kohm ) )
{
log_printf( &logger, " Rwb2 : %.2f kOhm\r\n", res_kohm );
Delay_ms ( 100 );
}
}
log_printf( &logger, " ----------------------------\r\n" );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
Delay_ms ( 1000 );
}
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
