Monitor current flow in high-speed and demanding environments with ACS37030 and STM32L073RZ
DC to 5MHz bandwidth, galvanically-isolated current sensing solution
Published Nov 12, 2024
Click board™
Hall Current 21 Click
Dev. board
Nucleo-64 with STM32L073RZ MCU
Compiler
NECTO Studio
MCU
STM32L073RZ
Measure current with high isolation and wide bandwidth for fast, reliable monitoring ideal for power supplies, data centers, and solar converters
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Hardware Overview
How does it work?
Hall Current 21 Click is based on the ACS37030, a DC to 5MHz bandwidth, a galvanically-isolated current sensor from Allegro Microsystems, designed to provide precise current measurements across a wide frequency range, ideal for applications requiring fast and accurate current monitoring. The ACS37030 offers bidirectional current sensing, with a range of ±65A and a sensitivity of 20.3mV/A, allowing for precise monitoring of both positive and negative currents. It is AEC-Q100 Grade 0 qualified, ensuring high reliability and robustness, even in harsh environments. Additionally, its wide operating bandwidth and low noise make it suitable for fast control loops and monitoring high-speed switching currents. This Click board™ is ideal for various applications, including power supplies for servers and data centers, solar DC-DC converters, and other high-performance power management systems that demand fast, accurate, and isolated
current sensing. The ACS37030 uses two distinct signal paths for current sensing: a Hall-effect element that captures DC and low-frequency currents and an inductive coil that measures high-frequency currents. Combining the outputs of both paths, this sensor achieves broad frequency coverage with minimal noise, ensuring reliable performance in various operating conditions. As the frequency increases, the coil's properties enhance the signal-to-noise ratio (SNR), further reducing noise at the output and ensuring clean and accurate measurements. The sensor's innovative design provides a high level of isolation. The magnetic coupling between the current flow in the conductor and the sensor elements ensures that the current is sensed without direct physical contact, allowing for an isolation rating of 3500 VRMS between the primary and secondary signal leads. This rating provides a working voltage of up to 840VRMS, making it suitable for applications
requiring high isolation, such as industrial and automotive environments. The ACS37030 outputs an analog signal that varies linearly with the bidirectional AC or DC primary current within the range specified. Then, it sends its analog output to the ADC122S101, a two-channel 12-bit A/D converter from Texas Instruments that uses a standard 4-Wire SPI serial interface to communicate with the host MCU. This ADC is based on a successive/approximation register architecture with an internal track-an-hold circuit and fully specified over a sample rate range of 500ksps to 1Msps. 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
Nucleo-64 with STM32L073RZ 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)
192
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
20480
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
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32L073RZ MCU 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 Hall Current 21 Click driver.
Key functions:
hallcurrent21_read_voltage_avg- This function reads a desired number of ADC samples and calculates the average voltage level of the selected input channel.hallcurrent21_calib_resolution- This function reads the sensor voltage reference and calibrates the data resolution at a known load current.hallcurrent21_read_current- This function reads the input current level [A].
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 Hall Current 21 Click example
*
* # Description
* This example demonstrates the use of Hall Current 21 Click board by reading and
* displaying the input current measurements.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and calibrates the data resolution at 3A load current.
*
* ## Application Task
* Reads the input current measurements and displays the results on the USB UART
* approximately once per second.
*
* @note
* The measurement range is approximately: +/- 65A.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "hallcurrent21.h"
// Load current [A] used for the data resolution calibration process.
#define HALLCURRENT21_CALIBRATING_CURRENT 3.0f
static hallcurrent21_t hallcurrent21;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
hallcurrent21_cfg_t hallcurrent21_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.
hallcurrent21_cfg_setup( &hallcurrent21_cfg );
HALLCURRENT21_MAP_MIKROBUS( hallcurrent21_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == hallcurrent21_init( &hallcurrent21, &hallcurrent21_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
log_printf( &logger, " Calibrating data resolution in 5 seconds...\r\n" );
log_printf( &logger, " Keep the load current set at %.1fA during the calibration process.\r\n",
HALLCURRENT21_CALIBRATING_CURRENT );
for ( uint8_t cnt = 5; cnt > 0; cnt-- )
{
log_printf( &logger, " %u\r\n", ( uint16_t ) cnt );
Delay_ms ( 1000 );
}
if ( HALLCURRENT21_ERROR == hallcurrent21_calib_resolution ( &hallcurrent21,
HALLCURRENT21_CALIBRATING_CURRENT ) )
{
log_error( &logger, " Calibrate resolution." );
for ( ; ; );
}
log_printf( &logger, " Data resolution calibration DONE.\r\n" );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float current = 0;
if ( HALLCURRENT21_OK == hallcurrent21_read_current ( &hallcurrent21, ¤t ) )
{
log_printf( &logger, " Current : %.1f A\r\n\n", current );
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
Additional Support
Resources
Category:Current sensor
