Convert high-voltage industrial signals to logic levels with MAX22196 and STM32F091RC
High-performance octal industrial sink/source digital input
Published Apr 29, 2024
Click board™
DIGI IN 2 Click
Dev Board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
Safely interface with high-voltage industrial signals and convert them to logic levels for controlling machinery and processes.
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Hardware Overview
How does it work?
DIGI IN 2 Click is based on the MAX22196, a high-performance octal industrial sink/source digital input IC from Analog Devices. This IC converts eight high-voltage (8V-24V) industrial inputs across channels 1 to 8 into standard logic-level outputs. It incorporates a serial interface for configuring and reading data in a serialized format via SPI. Each input channel can be individually set to operate as sinking (P-type) or sourcing (N-type), with built-in current limiters to reduce power wastage while adhering to the IEC 61131-2 standards. This Click board™ is ideal for various applications, including Programmable Logic Controllers (PLC), factory automation, and process control systems. A distinctive feature of the MAX22196 is its ability to meet IEC 61131-2 Type 1/3 or Type 2 digital input requirements using a single resistor (R7) set at 12kΩ. The device offers flexibility by allowing the users to turn off current sinks or sources. Furthermore, each input channel has a customizable glitch/debounce filter and an optional 16-bit down-counter for enhanced input signal processing. The MAX22196 can draw power from a field supply ranging from 8V to 24V, including a
green LED (VOK), to indicate the presence of a stable field supply. An on-chip 5V linear regulator is another hallmark of the MAX22196, capable of delivering up to 20mA of load current to the VA header, which is left unpopulated. This on-chip regulator can be enabled via the FUNC SEL "R" jumper by placing its position from OFF to ON state. While it's in the OFF position, the VA terminal presents a 5V linear regulator output, and the ON position presents a supply input powered by mikroBUS power rail™ (3.3V or 5V). Regarding communication, the DIGI IN 2 Click interfaces with the host MCU through SPI to perform input data reading, diagnostic data acquisition, and register configuration at speeds up to 12MHz. The voltages at the 1-8 input terminals are compared against internal references to determine whether the field binary output sensor is ON (logic 1) or OFF (logic 0). All eight inputs are simultaneously latched by the assertion of either latch LTC or CS pins, and the data is made available in a serialized form through the SPI. Notably, the MAX22196 can address up to four devices on a shared SPI bus using ADDR SEL jumpers for direct access, and it
supports daisy-chaining through the FUNC SEL "D" jumper. The MAX22196 also features a fault indicator (FLT pin) for communicating various operational errors to the host MCU, including power supply undervoltage, overtemperature conditions, and CRC errors. The READY RDY signal confirms that the MAX22196 is powered on and operational. CRC error detection is enabled by default for enhanced data integrity, which is particularly beneficial in both addressable and daisy-chain SPI configurations. To visually present the status of its digital inputs, the board is equipped with a 3x3 yellow LED driver crossbar matrix. The ninth LED, positioned in the lower-left corner, mirrors the functionality of the VOK LED, providing a quick visual reference for the board's operational status. 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 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
Click board™ 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 DIGI IN 2 Click driver.
Key functions:
digiin2_get_flt_pin- This function is used to get state of the FLT pindigiin2_write_reg- This function is used to write data into the selected register by using SPI serial interfacedigiin2_read_reg- This function reads a data byte from the selected register by using SPI serial interface
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 DIGI IN 2 Click example
*
* # Description
* This example demonstrates the use of DIGI IN 2 Click board by reading and
* displaying the state of the channels.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver, performs the click default configuration.
*
* ## Application Task
* Reads and displays on the USB UART the channel state every second.
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "digiin2.h"
static digiin2_t digiin2;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
digiin2_cfg_t digiin2_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.
digiin2_cfg_setup( &digiin2_cfg );
DIGIIN2_MAP_MIKROBUS( digiin2_cfg, MIKROBUS_1 );
if ( SPI_MASTER_ERROR == digiin2_init( &digiin2, &digiin2_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( DIGIIN2_ERROR == digiin2_default_cfg ( &digiin2 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
uint8_t channel_data = 0;
digiin2_pulse_latch( &digiin2 );
if ( DIGIIN2_OK == digiin2_read_reg( &digiin2, DIGIIN2_REG_DISTATE, &channel_data ) )
{
if ( channel_data & DIGIIN2_CHANNEL_1_MASK )
{
log_printf( &logger, "Channel 1 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 1 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_2_MASK )
{
log_printf( &logger, "Channel 2 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 2 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_3_MASK )
{
log_printf( &logger, "Channel 3 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 3 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_4_MASK )
{
log_printf( &logger, "Channel 4 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 4 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_5_MASK )
{
log_printf( &logger, "Channel 5 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 5 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_6_MASK )
{
log_printf( &logger, "Channel 6 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 6 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_7_MASK )
{
log_printf( &logger, "Channel 7 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 7 counter: LOW \r\n" );
}
if ( channel_data & DIGIIN2_CHANNEL_8_MASK )
{
log_printf( &logger, "Channel 8 counter: HIGH \r\n" );
}
else
{
log_printf( &logger, "Channel 8 counter: LOW \r\n" );
}
log_printf( &logger, "- - - - - - - - - - - - - -\r\n" );
}
else
{
log_error( &logger, " Read error." );
}
if ( DIGIIN2_PIN_STATE_HIGH == digiin2_get_flt_pin( &digiin2 ) )
{
uint8_t flt_data = 0;
digiin2_read_reg( &digiin2, DIGIIN2_REG_FAULT, &flt_data );
log_printf( &logger, "Fault1 data: 0x%.2X \r\n", ( uint16_t ) flt_data );
digiin2_read_reg( &digiin2, DIGIIN2_REG_FAULT2, &flt_data );
log_printf( &logger, "Fault2 data: 0x%.2X \r\n", ( uint16_t ) flt_data );
log_printf( &logger, "- - - - - - - - - - - - - -\r\n" );
}
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
