Unleash the power of lightning-fast AC/DC current measurements with LTS 6-NP and STM32F091RC
Empower your electrical insights
Published Feb 26, 2024
Click board™
LEM Click
Dev Board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Navigate the world of electrical currents with unrivaled speed and confidence using our solution, offering exceptional measurement performance for your projects
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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
Nucleo-64 with STM32F091RC MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
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 Nucleo-64 with STM32F091RC MCU as your development board.
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
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
