80-Cent Pedometer as a Pulse/Event Counter
erco
Posts: 20,256
Retasking an Ebay Pedometer (step counter) to count pulses from a BS2. Internal debounce circuitry limits count rate to 4 Hz, but if you need a slow cheap counter w/LCD display and power-off memory using just one I/O pin, it's gonna be hard to beat 80 cents: http://www.ebay.com/itm/151424158305
A simple mod to remove the internal pendulum and make 2 connections:
1) to battery - (wedged wire under button cell) and
2) to the switch contact through a 100K resistor
A 1 ms high pulse is sufficient to count:
You could add another wire to let the micro reset the counter if you like.
A simple mod to remove the internal pendulum and make 2 connections:
1) to battery - (wedged wire under button cell) and
2) to the switch contact through a 100K resistor
A 1 ms high pulse is sufficient to count:
FOR B0=1 TO 39 PULSOUT 0,1 PAUSE 220 ' counter starts missing under 220, call it 4 Hz max NEXT
You could add another wire to let the micro reset the counter if you like.
1000 x 800 - 210K
980 x 770 - 164K
Comments
It was some time ago, but I remember getting to about 12Hz reliably, far too slow to use for my goal of counting pulses from a GM tube. I needed at least 1000Hz.
Hey 12 Hz is 3x faster than 4 Hz, so I'll have to get one.
I better get 3, the twins love math and I'm sure they will want one each as toys.