Tach

[Charliem]

I was thinking of tring to make a tachometer.is the picaxe 18x capable?

[bgrabowski]

Yes, use the count command. Max frequency 25kHz. What transducer will you be using to turn revs into pulses?

[Charliem]

a hall effect sensor.is there any kind of mathimatical formula I need to use?

[bgrabowski]

It's very straightforward. Count the pulses for 1 second. This gives revs per second directly. You may want to display revs per minute, in which case divide by 60.

Assuming pin 0 used for input, the command would be:
count 0,1000,w0
'w0 now holds revs/sec
w1=w0/60
'w1 now holds revs/min

[Charliem]

Thenks for the info.Is there any way to have the output to read in the terminal window? maybe using the sertxd command?if so how would I do that? thanks again charlie

[robbiegrove]

Wouldn't you multiply it by 60, not divide it? To get info via serial just use the debug command..

rpmloop: count 1, 1000, w0
w1 = w0 * 60
debug w1 'w1 = rpm
goto rpmloop

[Bloody-orc]

it is still divide by 60