How to calculate rpm ?

[madara77]

Hi.I am trying to do serial communication with a machine. The machine has 6 cylinders. For communicating with the device i have to send commands to the machine. For the given commands the machine send back the data. For calculating rpm of the machine there is no command. Is there any indirect way of finding out rpm of the machine?

[RavensFan]

If the machine won't tell you its RPM, how do you think you are going to measure it?

Speed is generally measured with a sensor counting pulses for a period of time.  If the machine is not doing it itself and not reporting that number to you through the serial port, you are going to have to add that sensor yourself.

[NIquist]

If you are using serial communication you are limited to the command set of your device.  If it has no way to communicate its speed of revolution then you can't read that info through serial.  Can you set up an external sensor and count its revolutions?  What kind of "machine" is this?

[madara77]

I dont know if it helps, but there is a command which gives pure pulses in hex coded format. Does this help in any way to find rpm?

[RavensFan]

What does the command say?

I don't know what it means to "hex code pure pulses".

[crossrulz]

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@madara77 wrote:

I dont know if it helps, but there is a command which gives pure pulses in hex coded format. Does this help in any way to find rpm?

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Not really.  Due to the asynchronicity of the serial communications, that information is kind of worthless.  It would only be useful if you had the number of pulses in a given set amount of time.