Intermediate
30 min

Redefine fan control with MAX31760 and PIC18F57Q43

Stay cool, stay in control

Fan 2 Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

Fan 2 Click

Dev Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Command your fans with precision and finesse

A

A

Hardware Overview

How does it work?

Fan 2 Click is based on the MAX31760, a precision fan-speed controller from Analog Devices. It can measure temperature and adjust the fan speed to keep the temperature at the same level. Fan 2 Click can also control two fans at the same time. This Click board™ is designed to run on either 3.3V or 5V power supply. It communicates with the target microcontroller over the I2C interface, with additional functionality provided by the following pins on the mikroBUS™ line: INT, AN, RST, and CS. For example, you can set the limit at 25°C, and if the temperature goes over that, the Click board™ will activate the fan; it will keep working until the temperature is 25°C again. The MAX31760 integrates temperature sensing along with

precision PWM fan control. It accurately measures its local die temperature and the remote temperature of a discrete diode-connected transistor, such as a 2N3906 or a thermal diode commonly found on CPUs, graphics processor units (GPUs), and other ASICs. Multiple temperature thresholds, such as local high/overtemperature (OT) and remote high/overtemperature, can be set by an I2C-compatible interface. Fan speed is controlled based on the temperature reading as an index to a 48-byte lookup table (LUT) containing user-programmed PWM values. The flexible LUT-based architecture enables users to program a smooth nonlinear fan speed vs. temperature transfer

function to minimize acoustic fan noise. Two tachometer inputs allow for measuring the speeds of two fans independently. The Click board™ carries a 10-pole terminal block that allows easy connection for pairs of two, three, or four-wire DC fans on the standard way of connection via PWM, TACH, GND, and VFAN lines. A single onboard jumper setting enables a two or 3-wire fan connection. In addition, there are two points (DXP, DXN) on the same terminal for external temperature sensor connection. The click communicates with the MCU over a data interface voltage level of 3.3V only.

Fan 2 Click hardware overview image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

Used MCU Pins

mikroBUS™ mapper

Alert
PA0
AN
Shutdown
PA7
RST
Fan Fault
PD4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PA6
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB1
SCL
I2C Data
PB2
SDA
Power supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Fan 2 Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Charger 27 Click front image hardware assembly
PIC18F47Q10 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Charger 27 Click complete accessories setup image hardware assembly
Curiosity Nano with PICXXX Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
PIC18F57Q43 Curiosity MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.

2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.

DEBUG_Application_Output

Software Support

Library Description

This library contains API for Fan 2 Click driver.

Key functions:

  • fan2_generic_write_byte - Generic Byte Write function

  • fan2_read_tacho - Tachometer Read function

  • fan2_direct_speed_control - Direct Fan Speed Control function

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * \file main.c
 * \brief Fan 2 Click example
 *
 * # Description
 * This example demonstrates the use of Fan 2 Click board.
 * It demonstrates sensor measurements and fan control.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes I2C driver and executes a default configuration for Fan 2 click.
 * Also initializes UART logger for results logging.
 *
 * ## Application Task
 * Increments the fan speed from half speed to maximum, and on each step measures
 * the current fan speed in RPM and the remote temperature in Celsius.
 * Fan speed will be incremented/decremented each second for 10 percents.
 *
 * \author Nemanja Medakovic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "fan2.h"

// ------------------------------------------------------------------ VARIABLES

static fan2_t fan2;
static log_t logger;
static float fan2_speed;
static uint16_t fan2_curr_speed;
static float fan2_temp;
static uint8_t flag;

static char deg_cels[ 3 ] = { 176, 'C', 0 };

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init( void )
{
    fan2_cfg_t fan2_cfg;
    log_cfg_t log_cfg;

    /** 
     * 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.
    fan2_cfg_setup( &fan2_cfg );
    FAN2_MAP_MIKROBUS( fan2_cfg, MIKROBUS_1 );
    fan2_init( &fan2, &fan2_cfg );
    
    fan2_default_cfg( &fan2 );
    fan2_speed = FAN2_HALF_SPEED_PER;
    Delay_ms( 1000 );

    log_printf( &logger, "* * *  Fan 2 initialization done  * * *\r\n" );
    log_printf( &logger, "***************************************\r\n" );
    flag = 0;
}

void application_task( void )
{
    fan2_direct_speed_control( &fan2, fan2_speed );

    Delay_ms( 1000 );
    fan2_read_tacho( &fan2, FAN2_REG_TACH1_CNT, &fan2_curr_speed );
    
    fan2_read_temp( &fan2, FAN2_REG_REMOTE_TEMP_READ, &fan2_temp );

    log_printf( &logger, "* Fan 2 set speed : %.2f %%\r\n", fan2_speed );
    log_printf( &logger, "* Fan 2 current speed : %u RPM\r\n", fan2_curr_speed );
    log_printf( &logger, "* Fan 2 remote temperature : %.2f %s\r\n", fan2_temp, deg_cels );
    log_printf( &logger, "***************************************\r\n" );
    
    if ( flag == 0 ) {
        if ( fan2_speed < FAN2_MAX_SPEED_PER)
            fan2_speed += 10;
        else
            flag = 1;
    }
    
    if ( flag == 1 ) {
        if ( fan2_speed > FAN2_MIN_SPEED_PER)
            fan2_speed -= 10;
        else {
            fan2_speed = FAN2_HALF_SPEED_PER;
            flag = 0;
        }
    }
}

void main( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}


// ------------------------------------------------------------------------ END

Additional Support

Resources

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