RPM counter with Blockly

Dave Newbie

Hi, totally new to blockly. Trying to read RPM from a half hull senor which goes low twice in one revolution. Any help would be appreciated.

Francis Bauer

It sounds like your sensor just puts out simple high/low pulses per revolution. If so, you could probably use one of the counters in a cog to detect the pulse transistions. What voltages are we talking about here 12v, 5v or 3.3v? You will probably need to use a resistor or a transistor or level shifter to condition the incoming signal to be appropriate for the input pin of the propeller board being used.

Dave Newbie

Yes you are correct, works with 5V. So assume count low pulse. Not sure about the code.

Dave Newbie

Will this work FQ = (count(2, 1000));

kwinn

Dave Newbie wrote: »

Will this work FQ = (count(2, 1000));

It should, but if the RPM pulses go low twice per revolution then counting for 500mS should give you the RPM without any additional calculations.

Dave Newbie

Thanks that's a good idea