I am building a top octave generator using arduino: http://arduino.cc/forum/index.php/topic,116391.msg876275.html#msg876275
It is finished and working! Now i want to modify it by adding a frequency divider between Arduino and the optocouplers. I am using a 4040 counter.This i can not get to work. The voltage of the output from the 4040 counter drops when i connnect the optocoupler, so that the optocoupler does not turn on. My guess is that it has something to do with the optocouplers input impedance, but i am not sure how to fix it.
I am using this circuit: http://www.sparkfun.com/datasheets/Components/PS2532-Example.jpg
I hope i descripe the problem clearly enough. If not let me know.