FAN 8 Click

Fan 8 Click is a compact add-on board that represents a compliant fan controller. This board features the MAX6615, a fan-speed controller, and a dual-channel temperature monitor with external thermistor inputs from Maxim Integrated, now part of Analog Devices. The MAX6615 controls the speed of two cooling fans based on the temperatures of external thermistors and the device's internal temperature, reporting temperature values in a digital form using the I2C serial interface.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Aug 2021.
• Type : I2C type

Software Support

We provide a library for the FAN8 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 FAN8 Click driver.

Standard key functions :

• fan8_cfg_setup Config Object Initialization function.

  void fan8_cfg_setup ( fan8_cfg_t *cfg );

• fan8_init Initialization function.

  err_t fan8_init ( fan8_t *ctx, fan8_cfg_t *cfg );

• fan8_default_cfg Click Default Configuration function.

  err_t fan8_default_cfg ( fan8_t *ctx );

Example key functions :

• fan8_set_duty_cycle This function sets the duty cycle of the selected fan channel and waits until the duty cycle is set at the PWM output.

  err_t fan8_set_duty_cycle ( fan8_t *ctx, uint8_t fan_ch, uint8_t duty_cycle );

• fan8_measure_rpm This function measures the RPM of the selected fan channel.

  err_t fan8_measure_rpm ( fan8_t *ctx, uint8_t fan_ch, uint8_t num_pulses, uint16_t *fan_rpm );

• fan8_read_temperature This function reads the temperature from the thermistor attached to the selected temperature channel.

  err_t fan8_read_temperature ( fan8_t *ctx, uint8_t temp_ch, float *temperature );

Example Description

This example demonstrates the use of FAN 8 Click board.

The demo application is composed of two sections :

Application Init

Initializes the driver and performs the Click default configuration.

void application_init ( void )
{
    log_cfg_t log_cfg;    /**< Logger config object. */
    fan8_cfg_t fan8_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.
    fan8_cfg_setup( &fan8_cfg );
    FAN8_MAP_MIKROBUS( fan8_cfg, MIKROBUS_1 );
    err_t init_flag = fan8_init( &fan8, &fan8_cfg );
    if ( I2C_MASTER_ERROR == init_flag ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    init_flag = fan8_default_cfg ( &fan8 );
    if ( FAN8_ERROR == init_flag ) 
    {
        log_error( &logger, " Default Config Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
}

Application Task

Changes the speed of fans at both channels by changing the PWM duty cycle, then calculates the fans RPM from measured tachometer signal. It also reads the temperature of two thermistors. The results are being displayed to the USB UART where you can track their changes.

void application_task ( void )
{
    static uint8_t duty_cnt = FAN8_MIN_DUTY_CYCLE;
    static int8_t duty_inc = FAN8_DUTY_CYCLE_STEP_10;
    uint16_t fan_rpm = 0;
    float temperature = 0;

    if ( duty_cnt == FAN8_MAX_DUTY_CYCLE )
    {
        duty_inc = -FAN8_DUTY_CYCLE_STEP_10;
    }
    else if ( duty_cnt == ( FAN8_MIN_DUTY_CYCLE + FAN8_DUTY_CYCLE_STEP_10 ) )
    {
        duty_inc = FAN8_DUTY_CYCLE_STEP_10;
    }
    duty_cnt += duty_inc;

    log_printf( &logger, " - Channel 1 values -\r\n" );
    fan8_set_duty_cycle ( &fan8, FAN8_FAN_CHANNEL_1, duty_cnt );
    log_printf( &logger, " PWM Duty Cycle : %d\r\n", ( uint16_t ) duty_cnt );
    fan8_measure_rpm ( &fan8, FAN8_FAN_CHANNEL_1, FAN8_2_PULSES_PER_REVOLUTION, &fan_rpm );
    log_printf( &logger, " Last measured fan RPM : %u\r\n", fan_rpm );
    fan8_read_temperature ( &fan8, FAN8_TEMP_CHANNEL_1, &temperature );
    log_printf( &logger, " Temperature : %.2f C\r\n\r\n", temperature );

    log_printf( &logger, " - Channel 2 values -\r\n" );
    fan8_set_duty_cycle ( &fan8, FAN8_FAN_CHANNEL_2, duty_cnt );
    log_printf( &logger, " PWM Duty Cycle : %d\r\n", ( uint16_t ) duty_cnt );
    fan8_measure_rpm ( &fan8, FAN8_FAN_CHANNEL_2, FAN8_2_PULSES_PER_REVOLUTION, &fan_rpm );
    log_printf( &logger, " Last measured fan RPM : %u\r\n", fan_rpm );
    fan8_read_temperature ( &fan8, FAN8_TEMP_CHANNEL_2, &temperature );
    log_printf( &logger, " Temperature : %.2f C\r\n\r\n", temperature );

    if ( !fan8_check_fault_indicator ( &fan8 ) )
    {
        log_printf( &logger, " Fault detected!\r\n\r\n", temperature );
    }

    Delay_ms ( 500 );
}

Note

The MAX6615 measures the tachometer signal every 67s, therefore the fan RPM value will be updated once per 67s. An NTC 10K3 thermistor is required for proper temperature measurements.

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.FAN8

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.