EZO Carrier Click – pH

How does it work?

EZO Carrier Click – pH is based on the EZO™ pH, a pH measurement interface circuit board from Atlas Scientific. It allows you to interface a pH measurement probe, which measures the potential of hydrogen, by sinking the probe into the solvent you want to measure the pH. The EZO Carrier Click – pH comes with the BNC connector for interfacing the appropriate probe, which MIKROE also offers. The EZO™ pH needs to be isolated from the host MCU; therefore, this Click™ board comes with the Si8400AB, a bidirectional isolator from Skyworks. The isolator provides a standard bidirectional and I2C communication with a clock frequency of up to 1.7MHz.

The EZO™ pH circuit is a very sensitive device, and the sensitivity is what gives the pH circuit its accuracy. It is capable of reading micro-voltages that are bleeding into the solvent. So, to eliminate the electrical noise, besides the Si8400AB isolator, the power supply voltage is also isolated. For this purpose, this Click™ board is equipped with the ROE-0505S, a DC/DC converter from Recom. The EZO™ pH has a flexible calibration protocol allowing for single-point, two-point, or three-point calibration. The temperature compensation should be taken into account. The EZO™ pH features sleep mode, continuous operation, find function, export/import calibration, on-module status LED, and more.

EZO Carrier Click – pH can use a standard 2-wire UART interface to communicate with the host MCU with the default baud rate of 9600bps. While using the UART interface, you can use the library we provide or a simple ASCII set of commands. You can also choose a standard 2-wire I2C interface over the COMM SEL jumpers.

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.

Specifications

Pinout diagram

This table shows how the pinout on EZO Carrier Click – pH 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	NC
	NC	2	RST	INT	15	NC
ID COMM	CS	3	CS	RX	14	TX	UART TX
	NC	4	SCK	TX	13	RX	UART RX
	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

EZO Carrier Click – pH electrical specifications

Software Support

We provide a library for the EZO Carrier pH Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

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

Library Description

This library contains API for EZO Carrier pH Click driver.

Key functions

• ezocarrierph_send_cmd Send command function.

• ezocarrierph_send_cmd_with_par Send command function with parameter.

• ezocarrierph_send_cmd_check Check the sent command.

Example Description

This example demonstrates the use of EZO Carrier pH Click board™ by processing the incoming data and displaying them on the USB UART.

void application_task ( void )  
 { 
     log_printf( &logger, "Reading... rn" ); 
     ezocarrierph_send_cmd( &ezocarrierph, EZOCARRIERPH_CMD_SINGLE_READ ); 
     error_flag = ezocarrierph_rsp_check( &ezocarrierph, EZOCARRIERPH_RSP_OK ); 
     ezocarrierph_error_check( error_flag ); 
     Delay_ms( 5000 ); 
 }

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.EZOCarrierpH

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 MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE 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.