Change analog signals to digital with MAX22005 and STM32F446RE
Digitize your data
Published Oct 08, 2024
Click board™
ADC 18 Click
Dev. board
Nucleo 64 with STM32F446RE MCU
Compiler
NECTO Studio
MCU
STM32F446RE
Translate analog signals for data processing purposes
A
A
Hardware Overview
How does it work?
ADC 18 Click is based on the MAX22005, a high-performance twelve-channel analog-to-digital converter from Analog Devices. The MAX22005 has an integrated 24-bit delta-sigma ADC, input multiplexer, signal conditioning, and control logic block, allowing ADC to communicate with MCU through a high-speed serial interface. An integrated delta-sigma ADC is shared between all channels with an integrated 5ppm/°C precision reference. Using high-voltage, zero-drift input amplifiers, standard industrial analog input voltage ranges are converted to the ADC input voltage range. Input channels can be used as twelve single-ended, six differential, and up to eight multichannel configurable differential inputs. In total, the device supports up to 26 different configurations. The MAX22005 can also be configured as an analog-input
current-mode device using an external precision resistor per channel or configurable analog input using an external precision resistor and low-cost switch per channel. All input ports are robustly protected up to ±36V reverse polarity and ±2kV surge pulses without the need for TVS diodes and factory calibrated with a best-in-class system performance of less than 0.05% FSR Total-Unadjusted-Error (TUE) over temperature. ADC 18 Click communicates with MCU through a standard SPI interface and operates at clock rates up to 30MHz, for all configurations and information management and acquiring conversion results. In addition, it also uses several mikroBUS™ pins. An active-low reset signal routed on the RST pin of the mikroBUS™ socket activates a hardware reset of the system, while the INT pin on the mikroBUS™
socket represents a standard interrupt feature providing a user with feedback information. It also has an additional data-ready interrupt marked as RDY and routed on the AN pin of the mikroBUS™ socket, used to signal when a new ADC conversion result is available in the data register. This Click board™ can only be operated with a 3.3V logic voltage level. It also has an analog inputs external power supply terminal where it is necessary to bring ±15V to accept ± 10V inputs, whose full-scale range is ± 12.5V. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.
Features overview
Development board
Nucleo-64 with STM32F446RE 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-M4
MCU Memory (KB)
512
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
131072
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 STM32F446RE 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 ADC 18 Click driver.
Key functions:
adc18_set_active_channelThis function sets the active channel.adc18_start_conversionThis function starts the conversion with the selected data rate.adc18_read_voltageThis function reads RAW ADC value of previous conversion and converts it to voltage.
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 ADC18 Click example
*
* # Description
* This example demonstrates the use of ADC 18 click board by reading
* the voltage from 12 analog input single-ended channels.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and logger, and performs the click default configuration.
*
* ## Application Task
* Reads and displays the voltage from 12 analog input single-ended channels
* on the USB UART approximately once per second.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "adc18.h"
static adc18_t adc18;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
adc18_cfg_t adc18_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.
adc18_cfg_setup( &adc18_cfg );
ADC18_MAP_MIKROBUS( adc18_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == adc18_init( &adc18, &adc18_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( ADC18_ERROR == adc18_default_cfg ( &adc18 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
static uint8_t channel = ADC18_CH_AI1_SINGLE_ENDED;
if ( ADC18_OK == adc18_set_active_channel ( &adc18, channel ) )
{
adc18_start_conversion ( &adc18, ADC18_DATA_RATE_225_SPS );
// Waits for the availability of the conversion result
while ( adc18_get_rdy_pin ( &adc18 ) );
adc18_stop_conversion ( &adc18 );
float voltage;
if ( ADC18_OK == adc18_read_voltage ( &adc18, &voltage ) )
{
log_printf ( &logger, "Channel AI%u: %.2f V\r\n", channel + 1, voltage );
if ( ++channel > ADC18_CH_AI12_SINGLE_ENDED )
{
channel = ADC18_CH_AI1_SINGLE_ENDED;
log_printf ( &logger, "\r\n" );
Delay_ms ( 1000 );
}
}
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
