Temp&Hum 27 Click

How does it work?

Temp&Hum 27 Click is based on the HS4001, a high-performance MEMS-based relative humidity and temperature sensor from Renesas, which delivers fully calibrated and temperature-compensated digital output over a standard I2C interface. This board offers highly accurate and reliable temperature and humidity sensing for a wide range of industrial and automotive applications. Designed to meet demanding environmental requirements, the HS4001 features integrated NIST-traceable calibration, ISO/IEC 17025-compliant production testing, and exceptional sensor-level protection that ensures long-term stability and resistance to environmental stress, aging, and volatile compounds.

With a wide operating temperature range from -40°C to +125°C for industrial use and -40°C to +105°C for automotive applications, this sensor achieves typical accuracy levels of ±1.5%RH for humidity and ±0.2°C for temperature within the critical range of -10°C to +80°C. It supports multiple programmable resolution settings, up to 14-bit resolution with a typical RH resolution of 0.04%, and enables a fast typical humidity response time of just 4 seconds. These features make Temp&Hum 27 Click a solution for climate control systems, HVAC equipment, building automation, medical instrumentation, weather stations, home appliances, and various portable or data logging devices operating in both controlled and harsh environments.

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 HS4001 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.

This Click board™ uses an I2C interface with clock speeds of up to 400kHz, ensuring fast communication with the host MCU. Beyond communication pins, this board is also equipped with alert (ALR) pin to indicate when a measurement is active in periodic measurement mode or to be used to trigger an interrupt on the host MCU so an appropriate action can be taken if the temperature or humidity is outside of the desired limits. To manage the operation of the HS4001 sensor, Temp&Hum 27 Click integrates the MAX40200 from Analog Devices that enables or disables the sensor through the EN pin.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. It also comes equipped with a library containing functions and example code that can be used as a reference for further development.

Click Snap

Click Snap is an innovative feature of our standardized Click add-on boards, designed to bring greater flexibility and optimize your prototypes. By simply snapping the PCB along predefined lines, you can easily detach the main sensor/IC/module area, reducing the overall size, weight, and power consumption - ideal for the final phase of prototyping. For more details about Click Snap, visit the official page dedicated to this feature.

Specifications

Pinout diagram

This table shows how the pinout on Temp&Hum 27 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	EN	Device Enable
	NC	2	RST	INT	15	ALR	Alert Interrupt
ID COMM	CS	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Temp&Hum 27 Click electrical specifications

Software Support

TempHum 27 Click demo application is developed using the NECTO Studio, ensuring compatibility with mikroSDK's open-source libraries and tools. Designed for plug-and-play implementation and testing, the demo is fully compatible with all development, starter, and mikromedia boards featuring a mikroBUS™ socket.

Example Description

This example demonstrates the use of the TempHum 27 Click board by reading ambient temperature and relative humidity values using periodic measurements. After initializing the device and starting the periodic mode at 1 Hz, the application waits for the ALERT pin to indicate data readiness and then logs the measurements to the USB UART terminal.

Key Functions

• temphum27_cfg_setup This function initializes Click configuration structure to initial values.
• temphum27_init This function initializes all necessary pins and peripherals used for this Click board.
• temphum27_get_alert_pin This function reads the logic level of the ALR (alert) pin.
• temphum27_start_periodic_meas This function configures and starts periodic measurement mode at the specified frequency.
• temphum27_read_data_periodic This function reads temperature and/or humidity data in periodic measurement mode.
• temphum27_read_sensor_id This function reads the unique 32-bit sensor ID.

Application Init

Initializes the logger and the Click driver, resets the device, reads and logs the sensor ID, and starts periodic measurements with a 1-second output rate.

Application Task

Waits for the ALERT pin to go low indicating new measurement data is available, then reads and logs the temperature and humidity values.

Application Output

This Click board can be interfaced and monitored in two ways:

• Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
• UART Terminal - Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.

Additional Notes and Information

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.