{"id":1574,"date":"2024-06-26T14:03:23","date_gmt":"2024-06-26T14:03:23","guid":{"rendered":"https:\/\/iotthinghub.com\/?p=1574"},"modified":"2024-08-11T16:07:06","modified_gmt":"2024-08-11T16:07:06","slug":"rpm-meter","status":"publish","type":"post","link":"https:\/\/iotthinghub.com\/?p=1574","title":{"rendered":"RPM Meter"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

In this project we use IR Tx diode and IR Rx diode. The sensor circuit diagram is as follow-<\/p>\n\n\n\n

\n
\n
\"\"<\/figure>\n<\/div>\n\n\n\n
\n

The RPM meter based on two procedures<\/p>\n\n\n\n

    \n
  1. Count the pulse<\/li>\n\n\n\n
  2. Calculate the value per second<\/li>\n<\/ol>\n\n\n\n

    It is easy to calculate pulse using external interrupt pin. Let use ATmega8 for this purpose. The logic should be as soon as any falling edge is found, it triggered an external interrupt. Now to enable external interrupt on falling edge<\/p>\n<\/div>\n<\/div>\n\n\n

    \n  #include<avr\/interrupt.h>\nsei();\t\/\/Global Interrupt Enable\nGICR |=(1<<INT0);\t\/\/ External Interrupt Request 0 Enable\nMCUCR|=(1<<ISC01);  \/\/ The falling edge of INT0 generates an interrupt request\nISR(TIMER1_COMPA_vect)\n{\n   Global_Variable ++; \/\/ update your global variable\n}\n<\/pre><\/div>\n\n\n
    The next step is to make a delay of 1s with the help of Timer so that we can easily find the counting value of the pulse. This counting pulse is the RPS (Revolution Per second). Let use Timer1 with F_CPU=8MHz and Prescaler=256. The logic is<\/p>\n\n\n
    \n TCCR1B|=(1<<WGM12);   \/\/CTC mode with TOP=OCR1A\n TCCR1B|=(1<<CS12);      \/\/Prescaler=256\n OCR1A=31249;   \/\/F_CPU=8MHz,Prescaler=256  Delay=  1s\n TIMSK|=(1<<OCIE1A); \/\/Timer\/Counter1, Output Compare A Match Interrupt Enable\n ISR(TIMER1_COMPA_vect)\n {\n   rps=  Global_Variable;  \/\/RPS Value\n   rpm=  Global_Variable *60;  \/\/RPM Value\n   Global_Variable =0;\n }\n<\/pre><\/div>\n\n\n
    Since for purity external interrupt will be executed first than the timer compare interrupt. The main program is as follow-<\/p>\n\n\n
    \n\/************************************************************************************************\n*************************************************************************************************\n*************************************RPM Meter***********************************************\n*************************************************************************************************\n\t\tSubeer Kumar Sarkar\n\t\tElectrical & Electronic Engineer\n************************************************************************************************\n************************************************************************************************\n***********************************************************************************************\/\n#include<stdio.h>\n#include<avr\/io.h>\n#include<avr\/interrupt.h>\n#include"lcd.h"\nfloat rpm,sample=0,rps;\nchar display[16];\nint main(void)\n{\nLCD_INIT(); \t\t\t\t\t\t\t\/\/LCD Initilation\nsei();\t\t\t\t\t\t\t\t\t\/\/Globel Interrupt Enable\nGICR |=(1<<INT0);\t\t\t\t\t\t\/\/External Interrupt Request 0 Enable\nMCUCR|=(1<<ISC01);\t\t\t\t\t\t\/\/The falling edge of INT0 generates an interrupt request\nTCCR1B|=(1<<WGM12); \t\t\t\t\t\/\/CTC mode with TOP=OCR1A\nTCCR1B|=(1<<CS12);\t\t\t\t\t\t\/\/Prescaler=256\nOCR1A=31249;\t\t\t\t\t\t\t\/\/F_CPU=8MHz,Prescaler=256  Delay=  1s\nTIMSK|=(1<<OCIE1A);\t\t\t\t\t    \/\/Timer\/Counter1, Output Compare A Match Interrupt Enable\nwhile(1)\n{\n\tLCD_write_string(1,1,"***RPM Meter***");\n\tsprintf(display,"RPM=%.0fRPS=%.0f",(double)rpm,(double)rps);\n\tLCD_write_string(1,2,display);\n}\nreturn 0;\n}\nISR(INT0_vect)\n{\n  sample++;\n}\nISR(TIMER1_COMPA_vect)\n{\n  rps=sample;\n  rpm=sample*60;\n  sample=0;\n}\n<\/pre><\/div>\n\n\n
    \n
    \n
    \n
    download<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n
    \n
    RPM meter.rar<\/a><\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
    In this project we use IR Tx diode and IR Rx diode. The sensor circuit diagram is as follow- The RPM meter based on two procedures It is easy to calculate pulse using external interrupt pin. Let use ATmega8 for this purpose. The logic should be as soon as any falling edge is found, it […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"class_list":["post-1574","post","type-post","status-publish","format-standard","hentry","category-timer-counter"],"_links":{"self":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts\/1574","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1574"}],"version-history":[{"count":15,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts\/1574\/revisions"}],"predecessor-version":[{"id":2597,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=\/wp\/v2\/posts\/1574\/revisions\/2597"}],"wp:attachment":[{"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1574"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1574"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iotthinghub.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1574"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}