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I want to merge Darkness and PIR Motion Sensor into one circuit


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the circuit on the right is a darkness sensor while on the left is a motion detector using PIR. I want to combine these two circuits into one. The motion sensor must only function if the LDR detects darkness and it must not function if the LDR doesn't detect any darkness. 

im making a school project, the circuit at the right is a darkness sensor using LDR and its steps and components are:
STEP 1 - Connect 555 timer IC on the breadboard
STEP 2 - Connect Pin 8 of 555 Timer to VCC of Battery
and Pin 1 of 555 Timer to GND of Battery
STEP 3 - Connect pin 4 to VCC and Connect pin 6 of 555 Timer to the pin 7 of 555 Timer
STEP 4 - Connect 330-ohm resistor to pin 7 and pin 8 of IC
STEP 5 - Connect 4.7uf polarized capacitor to pin 5 of IC and its negative side to the ground 
STEP 6 - Connect 0.01uf ceramic capacitor to pin 6 of IC and its negative side to the ground
STEP 7 - Connect 4.7k ohm resistor on pin 2 of IC and its negative side to the ground
STEP 8 - Connect LDR to pin 2 and VCC
STEP 9 - Connect 470-ohm resistor to pin 3 of IC and connect its other side to the anode of the LED and its cathode to the ground
STEP 10 - Test if the circuit works

while the circuit on the left is a motion detector alarm using PIR (HC-SR501) and its steps and components are: 
STEP 1 - Connect 555 timer IC on the breadboard and a 74HC04 IC
STEP 2 - Connect Pin 8 of 555 Timer to VCC of Battery
and Pin 1 of 555 Timer to GND of Battery. Also connect pin 14 of 74HC04 IC to VCC and pin 7 of 74HC04 IC to GND.
STEP 3 - Connect pin 4 to VCC and Connect pin 6 of 555 Timer to the pin 7 of 555 Timer
STEP 4 - Connect 100-kilo ohm resistor to pin 7 of 555 IC and its other side to the VCC
STEP 5 - Connect 4.7uf polarized capacitor to pin 7 of 555 IC and its negative side to the ground 
STEP 6 - Connect 0.01uf ceramic capacitor to pin 5 of 555 IC and its negative side to the ground
STEP 7 - Connect a buzzer to pin 3 of 555 IC and its negative side to the ground
STEP 8 - Connect the pin 2 of 555 IC to pin 12 of 74HC04 IC 
STEP 9 - Connect the GND of PIR to the ground, its power pin to the VCC and its Signal/output to the pin 13 of 74HC04 IC 
STEP 10 - Test if the circuit works

do u have any suggestions on how we can merge the two circuit into one according to the said output?IMG_5225.thumb.png.aed6f24527dee523b2fcdf89f979bb68.png

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  • 2 weeks later...

I think it will be much easier if you switch to Arduino. You will need to connect the PIR output to a digital pin. You will also need to conenct the LDR to an analog pin of the Arduino. By using the digitalRead and analogRead functions you can read the PIR and LDR sensor outputs. Then you can connect to the Arduino and turn on a relay/led/buzzer whatever you wish to control. 

https://www.theengineeringprojects.com/2017/08/pir-sensor-arduino-interfacing.html

https://www.hackster.io/electronicsfan123/interfacing-arduino-uno-with-ldr-8760ba

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