Hello, My plan is to have a photoresistor sense light and the resistance of this photoresistor be sent to a comparator and this will output a high based on the light (making it output a high, when a low resistance or light is detected on the photoresistor), the high output from the comparator will feed into a 555 timer that is set up in maybe (flip flop mode) and set up to output the 555 timer to 2 ms, to rotate my servo 180 degrees.
I am not sure is this would be the correct way to do it. If this even makes sense.
My ultimate goal which I will attach pic below is to have mini solar panels glued to a servo that will be in the zero degrees position and a photoresistor in between that would sense the light. The piece of paper in the picture will eventually be a 3d printed cover, that will have a hole for the photoresistor and when no light is shining, the panels will be covered. When a certain amount of light is shining, it will rotate the servo 180 degrees, exposing the panels to the light.
Sorry is this sound really "Out there", I just like to try new things and see what is feasible.
Thanks and later I'm thinking about adding an Arduino UNO to add more functionality.
TomGeorge:
Hi,
Yes, it is possible.
google lm555 servo control
You should be able to adapt/hack a circuit from there.
Tom...
Thanks for reply tom, i am beginner/intermediate with electronics circuitry. So im not 100% sure,
did that sound right to go photoresistor to a comparator to 555 timer to servo??
Thanks again
tjones9163:
later I'm thinking about adding an Arduino UNO to add more functionality.
Learning from the 555 side of the project will be interesting, of course, but I would be very inclined to ditch that approach and go straight into the Arduino. That might just be me, though. If it was my project (unless there is some constraint forcing you down the 555 route) it wouldn't be so much adding an Arduino as replacing the 555 with an Arduino.
I'm also wondering why you would want to bother covering the (inoperative, in the dark) panels in the first place?
Willpatel_Kendmirez:
Learning from the 555 side of the project will be interesting, of course, but I would be very inclined to ditch that approach and go straight into the Arduino. That might just be me, though. If it was my project (unless there is some constraint forcing you down the 555 route) it wouldn't be so much adding an Arduino as replacing the 555 with an Arduino.
I'm also wondering why you would want to bother covering the (inoperative, in the dark) panels in the first place?
[/quote
thanks for the response. In the long run, it would be mounted to a 3d printed car and it would be easier to move around with the panels retracted in.
You can’t use just one 555 timer chip to generate a servo signal you need tow.
A servo signal is not just a square wave 2mS oscillation, it is 2mS pulses at a rate of 50 per second. That will move the servo to one position but to have to move it back sometimes to an other position and that will need a shorter pulse but still at 50 times a second. So you need one 555 to act in a monostable mode at a pulse width determined by your Arduino and another 555 to trigger the monostable at 50Hz.
Just use the Arduino’s servo libiary and have done.
