Fan Click

How does it work?

Fan Click is based on the EMS2301, a single/multiple RPM-based PWM fan controller from Microchip. The EMS2301 uses a programmable frequency driver and RPM-based algorithm with an internal clock to allow you to regulate the RPM of a given fan with 1% accuracy from 500 to 16K RPM. It also provides tachometer feedback for fan speed control available on TACH onboard terminal. The Fan Click can operate in either a closed-loop fashion or as a directly PWM-controlled device. In a closed loop, the Fan Speed Control (FSC) algorithm can detect aging, stalled, or locked fans and will trigger an interrupt. In the FSC mode user determines a target tachometer count, and the PWM drive setting is automatically updated to achieve this target speed.

This Click board™ communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting a Fast Mode operation up to 400kHz. The EMS2301 monitors the fans’ tachometer signals to detect fan failure, and when the tachometer count is larger than the fan tachometer limit, the fan is considered failing. If that happens, the alert is triggered over the interrupt INT pin. Meanwhile, the fan driver attempts to alleviate a Stalled/Stack fan condition. Although a 3.3V voltage level only, this Click board™ uses a 5V rail to power a 4-wire fan over a 4-pin screw terminal. This board does not support an external power supply for the fan.

This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing 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 Fan 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	NC
	NC	2	RST	INT	15	INT	Interrupt
	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

Fan Click electrical specifications

Software Support

We provide a library for the Fan 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 Fan Click driver.

Key functions

• Generic write function.

• Generic read function.

• Fan click lock registers.

Example Description

This application is controller for powering and regulating.

 void application_task ( void ) 
 { 
     for ( uint8_t duty = FAN_DUTY_RATIO_0_PER; duty <= FAN_DUTY_RATIO_100_PER; 
           duty += FAN_DUTY_RATIO_10_PER ) 
     { 
         fan_setting( &fan, duty ); 
         log_printf( &logger, " Duty Ratio : %u%%rn", (uint16_t)duty ); 
         Delay_ms( 2000 ); 

         uint16_t tacho = 0; 

         fan_get_tach( &fan, &tacho ); 
         log_printf( &logger, " Rotation per minute : %urpmrnn", tacho ); 
         Delay_ms( 2000 ); 
     } 
 }

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.Fan

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.