Speedometer and odometer using pic 16f877a

Boney Varkey's picture


Joined: Apr 25, 2018

Replies: 1
Speedometer and odometer using pic 16f877a
April 25, 2018 - 2:54pm

I am interested in the project speedometer and odometer done using pic 18f877a. But I have a doubt.Velocity is given as (RPM (Diameter*pi))/60. After that its written Velocity = RPM* radius of wheel*0.37699.How the value 0.37699 is obtained. If (2*3.14)/60=0.104.Then how the value 0.37699

Aswinth Raj's picture


Joined: Aug 16, 2016

Replies: 987

Hi Boney,

Yes your calculation is correct ,,....


Actually is it 0.10471975512 to be more accurate.

But, this value is for m/s. since the rpm is also in rps and diameter of wheel is given in meters.

Speed is normally given in terms of km/hr. So we convert 0.10471975512m/s to km/h we will get the value 0.3769911184319698

which is used in the program.


Hope this helps you!!