Adjust and optimize critical settings in your projects with 67WR100KLF and STM32F446ZE
Trim with precision: Elevate control with our trimmer potentiometer
Published Oct 10, 2023
Click board™
POT 2 Click
Dev Board
Fusion for ARM v8
Compiler
NECTO Studio
MCU
STM32F446ZE
Our trimmer potentiometers are meticulously crafted to deliver unparalleled precision, enabling you to calibrate and fine-tune your equipment with exceptional accuracy, so you can achieve peak performance effortlessly
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Hardware Overview
How does it work?
POT 2 Click is based on the MCP1541, a precision voltage reference IC from Microchip is used to provide the voltage of 4.096V. is fed to an input of an operational amplifier, that acts as the buffer, with the unity gain. The output of the first buffer is fed to one end of a high-precision trimmer-potentiometer. The second end of the potentiometer is grounded, while the middle tap of the potentiometer is used as the input to a second buffer. The output of the second buffer is routed to the AN pin of the mikroBUS™, allowing the host microcontroller (MCU) to use the output voltage for any purpose. The design uses the MCP6022, a dual, rail-to-rail operational amplifier from Microchip. This operational amplifier is a perfect choice for this design, as it allows rail-to-rail
operation, uses a single power supply of 5V, and has a stable unity gain. Without the buffers, the variable impedance would affect the reference voltage. The reference voltage IC can provide less than 10 mA, with the significant voltage drop for output currents exceeding 2 mA. Therefore, the MCP6022 used as a dual buffer ensures good stability of the circuit. The potentiometer itself is a multi-turn type of potentiometer which provides high accuracy. It is equipped with a screw, which can be rotated 20 times between the end positions. This allows the resistance to be precisely selected. The fact that the screw fits tightly into the casing of the potentiometer, ensures that no resistance variations are possible, unlike the conventional knob or slider potentiometers.
POT 2 click is equipped with the SMD jumper, which is used to select the voltage reference for the potentiometer. There are two options available: 2.048V and 4.096V. These values are the most commonly used voltage references for different kinds of A/D converters. Most MCUs which use 3.3V for the power supply, do not have the option to use 4.096V (full voltage output of the MCP1541 IC), so an option to select 2.048V by dividing the output voltage of the MCP1541 IC, is very useful in that case. The voltage reference can be selected by moving the SMD jumper labeled as VRef SEL to the desired position (2.048V or 4.096V).
Features overview
Development board
Fusion for ARM 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 ARM® Cortex®-M based MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. 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 ARM v8 provides a fluid and immersive working experience, allowing access anywhere and under any
circumstances at any time. Each part of the Fusion for ARM 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 ARM 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)
512
Silicon Vendor
STMicroelectronics
Pin count
144
RAM (Bytes)
131072
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Fusion for ARM v8 as your development board.
Track your results in real time
Application Output
After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.
Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.
In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".
The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.
Software Support
Library Description
This library contains API for POT 2 Click driver.
Key functions:
pot2_generic_read- Generic read function
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* \file
* \brief Pot2 Click example
*
* # Description
* This demo-app shows the ADC values using POT 2 click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Configures clicks and log objects.
*
* ## Application Task
* Demo app reads ADC data and displays them as dec and hex values every second
*
* \author Jovan Stajkovic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "pot2.h"
// ------------------------------------------------------------------ VARIABLES
static pot2_t pot2;
static log_t logger;
static uint16_t adc_val;
static float voltage_val;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
pot2_cfg_t cfg;
/**
* 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.
pot2_cfg_setup( &cfg );
POT2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
if ( pot2_init( &pot2, &cfg ) == ADC_ERROR )
{
log_info( &logger, "---- Application Init Error ----" );
log_info( &logger, "---- Please, run program again ----" );
for ( ; ; );
}
log_info( &logger, "---- Application Init Done ----\r\n" );
voltage_val = 0;
adc_val = 0;
}
void application_task ( void )
{
if ( pot2_read_adc ( &pot2, &adc_val ) != ADC_ERROR )
{
log_printf( &logger, " ADC value : [DEC] %u, [HEX] 0x%x\r\n", adc_val, adc_val );
}
if ( pot2_read_pin_voltage ( &pot2, &voltage_val ) != ADC_ERROR )
{
log_printf( &logger, " Voltage value : %.2f\r\n", voltage_val );
}
log_printf( &logger, "------------------------------------------\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
