Temperature-Based Fan Control Using the MAXQ2000 Microcontroller

Introduction

Withitsnumerousfeatures,theMAXQ2000cancreateamultitudeofusefulapplications,suchascontrollingafan'sspeedbypulsewidthmodulation(PWM).AmongthemanyfeaturesoftheMAXQ2000areitstimerwithPWMandSerialPeripheralInterface(SPI™)and1-Wire®capabilities.ThisapplicationnotedescribeshowtheMAXQ2000canbeusedtodriveafanandchangeitsspeed,inrealtime,byPWM.ThisprocessrequirestheuseofanotherMaximproduct,theMAX1407multichanneldata-acquisitionsystem(DAS).UsingSPI,theMAXQ2000cancommunicatewiththeMAX1407(containinga16-bitanalog-to-digitalconverter[ADC]anddigital-to-analogconverter[DAC]).Asanalternativetousingathermistor,theMAXQ2000's1-WirebusmastercanbeusedinconjunctionwithatemperatureiButton(DS1920).Thesourcecodeusedinthisapplicationnoteisavailablefordownload.Temperature-BasedFanControlUsingtheMAXQ2000MicrocontrollerSep16,2005Abstract:ThisapplicationnotedescribeshowtouseaMAXQ2000microcontrollertocontrolDCfanspeedandmonitortemperaturefromathermistororiButton.IntroductionWithitsnumerousfeatures,theMAXQ2000cancreateamultitudeofusefulapplications,suchascontrollingafan'sspeedbypulsewidthmodulation(PWM).AmongthemanyfeaturesoftheMAXQ2000areitstimerwithPWMandSerialPeripheralInterface(SPI)and1-Wirecapabilities.ThisapplicationnotedescribeshowtheMAXQ2000canbeusedtodriveafanandchangeitsspeed,inrealtime,byPWM.ThisprocessrequirestheuseofanotherMaximproduct,theMAX1407multichanneldata-acquisitionsystem(DAS).UsingSPI,theMAXQ2000cancommunica