Unleash the power of lightning-fast AC/DC current measurements with LTS 6-NP and STM32F732IE
Empower your electrical insights
Published Sep 30, 2023
Click board™
LEM Click
Dev Board
Fusion for STM32 v8
Compiler
NECTO Studio
MCU
STM32F732IE
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Hardware Overview
How does it work?
LEM Click is based on the LTS 6-NP, a current transducer from Lem. It acts as a transformer with 2000 turns as a secondary coil and a load resistance of 2kΩ and above. The primary coil is a wire of the load itself, threaded through the middle of the current transducer while fully isolated and galvanic separated from the secondary coil. The LTS 6-NP uses the Hall effect to output the values regarding the current that passes through. The sensor output passes to the MCP607, a micropower CMOS operational amplifier from Microchip. It is a unity-gain stable, low offset voltage OpAmp that includes rail-to-rail
output, swing capability, and low input bias current. The output values from the operational amplifier pass to the MCP3201, a 12-bit analog-to-digital converter with an SPI serial interface from Microchip. The MCP3201 provides a single pseudo-differential input features on-chip, sample and hold, a maximum sampling rate of up to 100ksps, and more. The MCP3201 gets the 2.048V reference voltage from the MAX6106, a low-cost, micropower, low-dropout, high-output-current voltage reference from Analog Devices. The LEM Click uses the 3-Wire SPI serial interface of the MCP3201 to communicate with the host MCU supporting SPI 0
and SPI 3 modes with a frequency of up to 1.6MHz. The voltage amplified through the MCP607 can be directly monitored through the AN pin of the mikroBUS™ socket, which is useful if the host MCU has a higher ADC resolution. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR 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 STM32 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 STMicroelectronics, 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 STM32 v8 provides a fluid and immersive working experience, allowing
access anywhere and under any circumstances at any time. Each part of the Fusion for STM32 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 STM32 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-M7
MCU Memory (KB)
512
Silicon Vendor
STMicroelectronics
Pin count
176
RAM (Bytes)
262144
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 STM32 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 LEM Click driver.
Key functions:
lem_get_current- Function is used to read current in amperes or milliamperes
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 Lem Click example
*
* # Description
* Demo app measures and displays current by using LEM click board.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initalizes SPI, LOG and click drivers.
*
* ## Application Task
* This is an example that shows the capabilities of the LEM click by measuring
* current passing through the conductor placed through the hole on the sensor.
*
* \author Jovan Stajkovic
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "lem.h"
// ------------------------------------------------------------------ VARIABLES
static lem_t lem;
static log_t logger;
static float current;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
lem_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.
lem_cfg_setup( &cfg );
LEM_MAP_MIKROBUS( cfg, MIKROBUS_1 );
lem_init( &lem, &cfg );
log_printf( &logger, "---------------------\r\n" );
log_printf( &logger, " LEM Click \r\n" );
log_printf( &logger, "---------------------\r\n" );
}
void application_task ( void )
{
current = lem_get_current( &lem, LEM_MILIAMP_COEF );
log_printf( &logger, " Current : %.2f mA \r\n", current );
log_printf( &logger, "---------------------\r\n" );
Delay_ms( 1000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
