Achieve rapid conversion of analog signals into digital form with AD7490 and STM32F407VGT6
12-bit high speed, low power, 16-channel, successive approximation ADC
Published Mar 21, 2024
Click board™
ADC 24 Click
Dev.Board
Clicker 4 for STM32F4
Compiler
NECTO Studio
MCU
STM32F407VGT6
Invaluable tool for developers needing precise monitoring and data analysis solutions
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Hardware Overview
How does it work?
ADC 24 Click is based on the AD7490, a 12-bit, high-speed, low-power, 16-channel successive approximation ADC from Analog Devices. This ADC minimizes power consumption while maintaining high throughput rates, drawing just 2.5mA from a 5V supply at full capacity. It achieves up to 1MSPS throughput rates and incorporates a low noise, wide bandwidth track-and-hold amplifier that adeptly handles input frequencies beyond 1MHz. This Click board™ is particularly suited for applications requiring extensive system monitoring, such as multichannel system monitoring, power line monitoring, data acquisition, instrumentation, and process control. The AD7490 is equipped with 16 single-ended analog inputs, enhanced by a channel sequencer that enables the programmed and
sequential conversion of channels. The analog input range is configurable, offering a 0V to REFIN or a broader 0V to 2×REFIN range, achieved by the MCP1525 voltage reference from Microchip, with fixed 2.5V output. This flexibility allows users to tailor the ADC to various measurement requirements. For accurate utilization of the 0V to 2×REFIN measurement range, powering the IC with 5V is mandatory, which is achieved with 5V from the mikroBUS™ power rail. Moreover, the AD7490 supports multiple operational modes, such as Normal, Full Shutdown, Auto Shutdown, and Auto Standby, all of which are register-configurable. These modes provide users with various power management options to optimize the balance between power dissipation and throughput rate
based on specific application needs. The conversion process and data acquisition are made using CS and the serial clock signal, ensuring straightforward interfacing with microprocessors or DSPs (SPI/QSPI™/MICROWIRE™/ DSP compatible). The input signal is sampled at the falling edge of CS, initiating conversion at this juncture without any pipeline delays. 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
Clicker 4 for STM32F4 is a compact development board designed as a complete solution that you can use to quickly build your own gadgets with unique functionalities. Featuring an STM32F407VGT6 MCU, four mikroBUS™ sockets for Click boards™ connectivity, power management, and more, it represents a perfect solution for the rapid development of many different types of applications. At its core is an STM32F407VGT6 MCU, a powerful microcontroller by STMicroelectronics based on the high-performance
Arm® Cortex®-M4 32-bit processor core operating at up to 168 MHz frequency. It provides sufficient processing power for the most demanding tasks, allowing Clicker 4 to adapt to any specific application requirements. Besides two 1x20 pin headers, four improved mikroBUS™ sockets represent the most distinctive connectivity feature, allowing access to a huge base of Click boards™, growing on a daily basis. Each section of Clicker 4 is clearly marked, offering an intuitive and clean interface. This makes working with the
development board much simpler and, thus, faster. The usability of Clicker 4 doesn’t end with its ability to accelerate the prototyping and application development stages: it is designed as a complete solution that can be implemented directly into any project, with no additional hardware modifications required. Four mounting holes [4.2mm/0.165”] at all four corners allow simple installation by using mounting screws.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
10
Silicon Vendor
STMicroelectronics
Pin count
100
RAM (Bytes)
100
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 Clicker 4 for STM32F4 as your development board.
Track your results in real time
Application Output
After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.
After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.
Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.
Software Support
Library Description
This library contains API for ADC 24 Click driver.
Key functions:
adc24_get_voltage- This function reads the results of 12-bit ADC raw data and converts them to proportional voltage levels by using the SPI serial interfaceadc24_get_adc_data- This function reads a conversion result and selected channel by using the SPI serial interface
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 main.c
* @brief ADC 24 Click example
*
* # Description
* This example demonstrates the use of the ADC 24 Click board
* by reading and writing data by using the SPI serial interface
* and reading results of AD conversion.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of SPI module and log UART.
*
* ## Application Task
* The demo application reads the voltage levels
* from all 15 analog input channels and displays the results.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "adc24.h"
static adc24_t adc24;
static log_t logger;
static adc24_ctrl_t ctrl;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
adc24_cfg_t adc24_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.
adc24_cfg_setup( &adc24_cfg );
ADC24_MAP_MIKROBUS( adc24_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == adc24_init( &adc24, &adc24_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
ctrl.ch_sel = ADC24_CH_SEL_IN_0;
ctrl.pm = ADC24_PM_NORMAL;
ctrl.seq_shadow = ADC24_SEQ_SHADOW_AN_INPUT;
ctrl.weak = ADC24_WEAK_DOUT_THREE_STATE;
ctrl.range = ADC24_RANGE_VREF_5V;
ctrl.coding = ADC24_CODING_BIN;
log_info( &logger, " Application Task " );
log_printf( &logger, "_____________\r\n" );
}
void application_task ( void )
{
uint8_t ch_pos = 0;
float voltage = 0;
for ( uint8_t n_cnt = ADC24_CH_SEL_IN_0; n_cnt <= ADC24_CH_SEL_IN_15; n_cnt++ )
{
ctrl.ch_sel = n_cnt;
if ( ADC24_OK == adc24_get_voltage( &adc24, ctrl, &ch_pos, &voltage ) )
{
log_printf( &logger, " IN%u : %.3f V\r\n", ( uint16_t ) ch_pos, voltage );
}
Delay_ms( 100 );
}
log_printf( &logger, "_____________\r\n" );
Delay_ms( 1000 );
}
int main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
