Author Options:

is there an easy way to manually operate a cd tray? Answered

im in the middle of automating my trash can (i know i can just buy one, but what's the fun in that?) and i got the proximity sensor part to work, but i cant think of a way to turn a short burst (in the sensor test circuit i had the led on the output blinked once when my hand got close yay!) into a signal that would power an old cd motor until it opened, pushing the trash can lid open, wait about 10sec or so, then apply reverse polarity for 2sec or so until it closed. i might be able to use a microcontroller to do this, but im just getting into that and i don't want to use one for this unless there isn't another way. if it's relevant im using a 555 to generate a 38khz pulse to an ir led picked up by rpm7138. any ideas?



9 years ago

A simple 8-pin microcontroller would be the smallest and simplest (in terms of hardware) way of doing it.  But, you could use another 555 timer or two to do it.  Take a look on the web for a monostable timer using the 555.  Here's a fantastic link to get you started.


9 years ago

Try an SR latch with the Set connected to the sensor input and the Reset to a timer circuit. Trigger the timer with the output. To retract the motor, use a second timer with a longer period to wait and trigger a second SR latch, which will need its own timer like the first. Then use these outputs to trigger two transistors to drive the motor both ways.

It would be much easier to use a small uP though, and it would be a good introductory project too.