Altitude 5 Click

How does it work?

Altitude 5 Click as its foundation uses the KP236, a high-resolution analog barometric air pressure sensor based on a capacitive principle from Infineon Technologies. The KP236 surface is micro-machined with a monolithic integrated signal conditioning circuit implemented in BiCMOS technology that can measure pressure in a range from 40kPa up to 115kPa with an accuracy of ±1Pa over a wide operating temperature range at the industry’s lowest power. The KP236 is primarily developed for measuring barometric air pressure but can also be used in other application fields.

The pressure is detected by an array of capacitive surface micro-machined sensor cells. The sensor cell output is amplified, temperature-compensated, and linearized to obtain an output voltage proportional to the applied pressure. The transfer function for linearization is computed in the digital part of the sensor using a third-order polynomial calculation. The sensor converts pressure into an analog output signal; more precisely, the user can process the output signal in analog or digital form.

The analog output voltage of the KP236 can be converted to a digital value using MCP3221, a successive approximation A/D converter with a 12-bit resolution from Microchip, using a 2-wire I2C compatible interface, or can be sent directly to an analog pin of the mikroBUS™ socket labeled as AN. Selection can be performed by onboard SMD jumper labeled as ADC SEL to an appropriate position marked as AN and I2C. Using MCP3221 and I2C interface, data transfers at rates of up to 100kbit/s in the Standard and 400kbit/s in the Fast Mode.

Since the sensor for operation requires a 5V logic voltage level only, this Click board™ also features the PCA9306 voltage-level translator from Texas Instruments. The I2C interface bus lines are routed to the dual bidirectional voltage-level translator, allowing this Click board™ to work with both 3.3V and 5V MCUs properly.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VIO SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. 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.

Specifications

Pinout diagram

This table shows how the pinout on Altitude 5 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog Signal	AN	1	AN	PWM	16	NC
	NC	2	RST	INT	15	NC
	NC	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	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Altitude 5 Click electrical specifications

Software Support

We provide a library for the Altitude 5 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Altitude 5 Click driver.

Key functions

• altitude5_get_altitude Altitude 5 get altitude function.

• altitude5_get_pressure Altitude 5 get pressure function.

• altitude5_get_adc_voltage Altitude 5 get ADC voltage function.

Example Description

This library contains API for Altitude 5 Click driver. The demo application reads ADC value, calculate pressure and altitude.

 void application_task ( void )  
 { 
     static float pressure; 
     static float altitude; 

     altitude5_get_pressure( &altitude5, &pressure ); 
     log_printf( &logger, " Pressure    : %.2f mBar rn", pressure ); 
     Delay_ms( 100 ); 

     altitude5_get_altitude( &altitude5, &altitude ); 
     log_printf( &logger, " Altitude    : %.2f m rn", altitude ); 
     log_printf( &logger, "----------------------------rn" ); 
     Delay_ms( 1000 ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Altitude5

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.