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username
Nov4-04, 07:49 PM
Is there such a thing as a morse code ic timer chip or is the only way cascading 555's or something complicated like that. Eproms and machine code is ok if thats what it takes if its cheap and easy for my pc.

Only need maybe 3/4 pulses timed.

EDIT: want to modify my intercom into a system where you press the buzzer in way that lets me in with a simple code square wavish over time.

NoTime
Nov4-04, 09:31 PM
If your pc/os allows direct access to a port pins then it is pretty simple.
Set up your switch to provide the port pin high voltage.
Using the timer periodically poll the pin state.
Count the number of high states for your dash.
Count the number of high states for your dot.
Reset your pattern buffer after a certain period of inactivity.

MaximumTaco
Nov5-04, 08:56 AM
Use say a PICAXE microcontroller

username
Nov10-04, 07:17 AM
Thanks, one of those PICAXE chips should do the job nicely. I can not have my pc constanly connected to the intercom and really need the electronics in the same plastic housing. I could either power the chip from the intercom itself or use a small battery. Should be fun.