Extends your I2C bus using the CAN-physical layer with LT3960 and PIC32MZ1024EFH064
I2C to CAN-physical transceiver
Published Aug 06, 2023
Click board™
I2C to CAN Click
Dev Board
PIC32MZ clicker
Compiler
NECTO Studio
MCU
PIC32MZ1024EFH064
Engineered for resilience in challenging environments, this robust high-speed transceiver extends a single-master I2C bus at speeds up to 400kbps, utilizing the CAN-physical layer to ensure reliable communication even in harsh or noisy conditions
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Hardware Overview
How does it work?
I2C to CAN Click is based on the LT3960, I2C to CAN-Physical transceiver used to send and receive I2C data up to 400kbps using the CAN-Physical layer for differential signaling over twisted pair connections from Analog Devices. Using two integrated CAN transceivers, the LT3960 creates a differential proxy for each single-ended I2C clock and data signal capable of crossing harsh or noisy environments across two twisted pairs. Each transceiver consists of a transmitter and receiver capable of quickly converting an I2C dominant signal into a differential dominant signal and vice versa. Also, it extends functionality in environments with high common-mode voltages due to electrical noise or local ground potential differences. I2C to CAN Click communicates with MCU using the standard I2C 2-Wire interface to
read data and configure settings, supporting Fast Mode operation with a clock frequency up to 400kHz. The LT3960 provides a mode selection feature selectable via jumper labeled as MODE, where the user can choose between the Master or Slave mode of operation. The SHD pin routed to the CS pin of the mikroBUS™ socket is used to put the LT3960 in a low-power Shutdown mode, disabling both the LDO and transceivers and allowing selection between Master and Slave modes when enabled. The selection between Master and Slave modes is performed by positioning the SMD jumper labeled as MODE to an appropriate position marked as SLV and MST. When a jumper is on the MST position, Master mode is selected, and the EN/MODE pin of the LT3960 is tied to a high logic state while floating
this pin, more precisely positioning the SMD jumper to an SLV position, allows the user to select Slave mode of operation. This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows both 3.3V and 5V capable MCUs to use the I2C communication lines properly. Additionally, there is a possibility for the LT3960 power supply selection via jumper labeled as VIN SEL to supply the LT3960 from an external power supply terminal in the range from 4 to 60V or with VCC voltage levels from mikroBUS™ power rails. However, the 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
PIC32MZ Clicker is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit PIC32MZ microcontroller with FPU from Microchip, a USB connector, LED indicators, buttons, a mikroProg connector, and a header for interfacing with external electronics. Thanks to its compact design with clear and easy-recognizable silkscreen markings, it provides a fluid and immersive working experience, allowing access anywhere and under
any circumstances. Each part of the PIC32MZ Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the PIC32MZ Clicker programming method, using USB HID mikroBootloader, or through an external mikroProg connector for PIC, dsPIC, or PIC32 programmer, the Clicker board also includes a clean and regulated power supply module for the development kit. The USB Micro-B connection can provide up to 500mA of current, which is more than enough to operate all onboard
and additional modules. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several buttons and LED indicators. PIC32MZ Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC32
MCU Memory (KB)
1024
Silicon Vendor
Microchip
Pin count
64
RAM (Bytes)
524288
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 PIC32MZ clicker 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 I2C to CAN Click driver.
Key functions:
i2ctocan_set_slave_address- Set I2C Slave address functioni2ctocan_generic_write- I2C to CAN I2C writing functioni2ctocan_generic_read- I2C to CAN I2C reading function
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 I2cToCan Click example
*
* # Description
* This library contains API for the I2C to CAN click driver.
* This demo application shows an example of an I2C CAN click
* wired to the VAV Press click for reading
* differential pressure and temperature measurement.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of I2C module and log UART.
* After driver initialization and default settings,
* the app set VAV Press click I2C slave address ( 0x5C )
* and enable device.
*
* ## Application Task
* This is an example that shows the use of an I2C to CAN click board™.
* Logs pressure difference [ Pa ] and temperature [ degree Celsius ] values
* of the VAV Press click wired to the I2C to CAN click board™.
* Results are being sent to the Usart Terminal where you can track their changes.
*
* @note
* void get_dif_press_and_temp ( void ) - Get differential pressure and temperature function.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "i2ctocan.h"
#define I2CTOCAN_VAV_PRESS_DEV_ADDR 0x5C
#define I2CTOCAN_VAV_PRESS_CMD_START_PRESSURE_CONVERSION 0x21
#define I2CTOCAN_VAV_PRESS_PRESS_SCALE_FACTOR 1200
#define I2CTOCAN_VAV_PRESS_TEMP_SCALE_FACTOR 72
#define I2CTOCAN_VAV_PRESS_READOUT_AT_KNOWN_TEMPERATURE 105
#define I2CTOCAN_VAV_PRESS_KNOWN_TEMPERATURE_C 23.1
static i2ctocan_t i2ctocan;
static log_t logger;
static float diff_press;
static float temperature;
void get_dif_press_and_temp ( void ) {
uint8_t rx_buf[ 4 ];
int16_t readout_data;
i2ctocan_generic_read( &i2ctocan, I2CTOCAN_VAV_PRESS_CMD_START_PRESSURE_CONVERSION, &rx_buf[ 0 ], 4 );
readout_data = rx_buf[ 1 ];
readout_data <<= 9;
readout_data |= rx_buf[ 0 ];
readout_data >>= 1;
diff_press = ( float ) readout_data;
diff_press /= I2CTOCAN_VAV_PRESS_PRESS_SCALE_FACTOR;
readout_data = rx_buf[ 3 ];
readout_data <<= 8;
readout_data |= rx_buf[ 2 ];
temperature = ( float ) readout_data;
temperature -= I2CTOCAN_VAV_PRESS_READOUT_AT_KNOWN_TEMPERATURE;
temperature /= I2CTOCAN_VAV_PRESS_TEMP_SCALE_FACTOR;
temperature += I2CTOCAN_VAV_PRESS_KNOWN_TEMPERATURE_C;
}
void application_init ( void ) {
log_cfg_t log_cfg; /**< Logger config object. */
i2ctocan_cfg_t i2ctocan_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_printf( &logger, "\r\n" );
log_info( &logger, " Application Init " );
// Click initialization.
i2ctocan_cfg_setup( &i2ctocan_cfg );
I2CTOCAN_MAP_MIKROBUS( i2ctocan_cfg, MIKROBUS_1 );
err_t init_flag = i2ctocan_init( &i2ctocan, &i2ctocan_cfg );
if ( init_flag == I2C_MASTER_ERROR ) {
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
i2ctocan_default_cfg ( &i2ctocan );
log_info( &logger, " Application Task " );
Delay_ms ( 100 );
log_printf( &logger, "--------------------------------\r\n" );
log_printf( &logger, " Set I2C Slave Address \r\n" );
i2ctocan_set_slave_address ( &i2ctocan, I2CTOCAN_VAV_PRESS_DEV_ADDR );
Delay_ms ( 100 );
log_printf( &logger, "--------------------------------\r\n" );
log_printf( &logger, " Enable Device \r\n" );
log_printf( &logger, "--------------------------------\r\n" );
i2ctocan_enable_device( &i2ctocan );
Delay_ms ( 100 );
}
void application_task ( void ) {
get_dif_press_and_temp( );
log_printf( &logger, " Diff. Pressure : %.4f Pa\r\n", diff_press );
log_printf( &logger, " Temperature : %.4f C\r\n", temperature );
log_printf( &logger, "--------------------------------\r\n" );
Delay_ms ( 1000 );
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
/*!
* @file main.c
* @brief I2cToCan Click example
*
* # Description
* This library contains API for the I2C to CAN click driver.
* This demo application shows an example of an I2C CAN click
* wired to the VAV Press click for reading
* differential pressure and temperature measurement.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization of I2C module and log UART.
* After driver initialization and default settings,
* the app set VAV Press click I2C slave address ( 0x5C )
* and enable device.
*
* ## Application Task
* This is an example that shows the use of an I2C to CAN click board™.
* Logs pressure difference [ Pa ] and temperature [ degree Celsius ] values
* of the VAV Press click wired to the I2C to CAN click board™.
* Results are being sent to the Usart Terminal where you can track their changes.
*
* @note
* void get_dif_press_and_temp ( void ) - Get differential pressure and temperature function.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "i2ctocan.h"
#define I2CTOCAN_VAV_PRESS_DEV_ADDR 0x5C
#define I2CTOCAN_VAV_PRESS_CMD_START_PRESSURE_CONVERSION 0x21
#define I2CTOCAN_VAV_PRESS_PRESS_SCALE_FACTOR 1200
#define I2CTOCAN_VAV_PRESS_TEMP_SCALE_FACTOR 72
#define I2CTOCAN_VAV_PRESS_READOUT_AT_KNOWN_TEMPERATURE 105
#define I2CTOCAN_VAV_PRESS_KNOWN_TEMPERATURE_C 23.1
static i2ctocan_t i2ctocan;
static log_t logger;
static float diff_press;
static float temperature;
void get_dif_press_and_temp ( void ) {
uint8_t rx_buf[ 4 ];
int16_t readout_data;
i2ctocan_generic_read( &i2ctocan, I2CTOCAN_VAV_PRESS_CMD_START_PRESSURE_CONVERSION, &rx_buf[ 0 ], 4 );
readout_data = rx_buf[ 1 ];
readout_data <<= 9;
readout_data |= rx_buf[ 0 ];
readout_data >>= 1;
diff_press = ( float ) readout_data;
diff_press /= I2CTOCAN_VAV_PRESS_PRESS_SCALE_FACTOR;
readout_data = rx_buf[ 3 ];
readout_data <<= 8;
readout_data |= rx_buf[ 2 ];
temperature = ( float ) readout_data;
temperature -= I2CTOCAN_VAV_PRESS_READOUT_AT_KNOWN_TEMPERATURE;
temperature /= I2CTOCAN_VAV_PRESS_TEMP_SCALE_FACTOR;
temperature += I2CTOCAN_VAV_PRESS_KNOWN_TEMPERATURE_C;
}
void application_init ( void ) {
log_cfg_t log_cfg; /**< Logger config object. */
i2ctocan_cfg_t i2ctocan_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_printf( &logger, "\r\n" );
log_info( &logger, " Application Init " );
// Click initialization.
i2ctocan_cfg_setup( &i2ctocan_cfg );
I2CTOCAN_MAP_MIKROBUS( i2ctocan_cfg, MIKROBUS_1 );
err_t init_flag = i2ctocan_init( &i2ctocan, &i2ctocan_cfg );
if ( init_flag == I2C_MASTER_ERROR ) {
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
i2ctocan_default_cfg ( &i2ctocan );
log_info( &logger, " Application Task " );
Delay_ms ( 100 );
log_printf( &logger, "--------------------------------\r\n" );
log_printf( &logger, " Set I2C Slave Address \r\n" );
i2ctocan_set_slave_address ( &i2ctocan, I2CTOCAN_VAV_PRESS_DEV_ADDR );
Delay_ms ( 100 );
log_printf( &logger, "--------------------------------\r\n" );
log_printf( &logger, " Enable Device \r\n" );
log_printf( &logger, "--------------------------------\r\n" );
i2ctocan_enable_device( &i2ctocan );
Delay_ms ( 100 );
}
void application_task ( void ) {
get_dif_press_and_temp( );
log_printf( &logger, " Diff. Pressure : %.4f Pa\r\n", diff_press );
log_printf( &logger, " Temperature : %.4f C\r\n", temperature );
log_printf( &logger, "--------------------------------\r\n" );
Delay_ms ( 1000 );
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
