Accurately measure temperature with isolation in demanding applications with ISOTMP35-Q1 and ATmega328P
Automotive-grade isolated temperature sensing solution with analog output
Published Dec 03, 2024
Click board™
Temp ISO Click
Dev. board
Arduino UNO Rev3
Compiler
NECTO Studio
MCU
ATmega328P
Isolated temperature monitoring in high-voltage environments, ideal for HV battery systems, power electronics, and industrial applications
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Hardware Overview
How does it work?
Temp ISO Click is based on the ISOTMP35-Q1, an automotive-grade isolated temperature sensor with analog output from Texas Instruments. This sensor is the first of its kind to integrate an isolation barrier with a withstand voltage of up to 3000VRMS, along with a temperature sensor that provides a linear analog output proportional to temperature, offering a slope of 10mV/°C across a wide range of –40°C to 150°C. This Click board™ can achieve precise, isolated temperature measurements while simplifying the design and reducing costs in high-voltage environments. It is an essential tool for applications such as HV battery management systems, high-voltage switching circuits, and thermal protection of power electronics. The ISOTMP35-Q1 enables accurate temperature measurements directly at high-voltage heat sources such as HV FETs, IGBTs, or contactors without requiring additional isolation circuitry. This design minimizes thermal lag, delivering faster and more precise thermal responses compared to traditional setups where the sensor must be placed farther
from the heat source to meet isolation requirements. These capabilities make it ideal for applications in high-voltage environments and battery systems with stacked configurations for high voltage output. This sensor features a robust UL 1577-compliant isolation barrier that ensures long-term reliability, supporting an isolation barrier life exceeding 50 years. It is also AEC-Q100 qualified, with HBM ESD classification level 2 and CDM ESD classification level C5, making it highly suitable for demanding automotive and industrial applications. The sensor delivers a maximum temperature accuracy of ±2.0°C and provides a rapid thermal response due to its optimized package design, which ensures excellent heat flow and minimizes thermal mass. This Click board™ is designed in a unique format supporting the newly introduced MIKROE feature called "Click Snap." Unlike the standardized version of Click boards, this feature allows the main sensor area to become movable by breaking the PCB, opening up many new possibilities for implementation. Thanks to the
Snap feature, the ISOTMP35-Q1 can operate autonomously by accessing its signals directly on the pins marked 1-8. Additionally, the Snap part includes a specified and fixed screw hole position, enabling users to secure the Snap board in their desired location. The ISOTMP35-Q1 outputs a linear analog voltage that is proportional to temperature, allowing easy integration with the host MCU through the AN pin of the mikroBUS™ socket. The high accuracy and fast response time of this Click board™ make it an excellent choice for monitoring high-voltage components, enabling improved safety in automotive and industrial systems. 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
Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an
ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the
first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
32
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
2048
You complete me!
Accessories
Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P 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 Arduino UNO board with our Click Shield for Arduino UNO, 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 Arduino UNO Rev3 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 Temp ISO Click driver.
Key functions:
tempiso_read_temperature- This function reads the voltage level from AN pin and converts it to temperature in degrees Celsius.tempiso_read_voltage_avg- This function reads a desired number of ADC samples and calculates the average voltage level.tempiso_set_vref- This function sets the voltage reference for Temp ISO click driver.
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 Temp ISO Click Example.
*
* # Description
* This example demonstrates the use of Temp ISO click board by reading
* and displaying the temperature measurements.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and logger.
*
* ## Application Task
* Reads the temperature measurement in degrees Celsius and displays
* the results on the USB UART approximately once per second.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "tempiso.h"
static tempiso_t tempiso; /**< Temp ISO Click driver object. */
static log_t logger; /**< Logger object. */
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
tempiso_cfg_t tempiso_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.
tempiso_cfg_setup( &tempiso_cfg );
TEMPISO_MAP_MIKROBUS( tempiso_cfg, MIKROBUS_1 );
if ( ADC_ERROR == tempiso_init( &tempiso, &tempiso_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
float temperature = 0;
if ( TEMPISO_OK == tempiso_read_temperature ( &tempiso, &temperature ) )
{
log_printf( &logger, " Temperature: %.1f degC\r\n\n", temperature );
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:Temperature & humidity
