DIY Parking Sensor Circuit using IC 555 and IC LM324 is smart device as it helps driver while parking a car, also it finds nearby things that can block the way.
Circuit has two parts:
Transmitter Circuit: which sends IR light using IR LED around the car.
Receiver Circuit: which gets back the IR light if it hits something.
Also, it checks how far the object is and turns ON the LEDs to warn the driver.
Circuit Working:
Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistors (All resistors are 1/4 watt unless specified) | 10k | 1 |
| 4.7k | 1 | |
| 1.5k | 1 | |
| 33Ω | 1 | |
| 1M | 2 | |
| 1k | 8 | |
| Capacitors | Ceramic 47pF | 1 |
| Electrolytic 1μF 25V | 2 | |
| Electrolytic 100μF 25V | 2 | |
| Semiconductors | IC LM324 | 1 |
| IC NE 555 | 1 | |
| Diode 1N4148 | 2 | |
| IR LED Transmitter | 1 | |
| IR LED Receiver | 1 | |
| LED Green 5mm 20mA | 1 | |
| LED Yellow 5mm 20mA | 1 | |
| LED Red 5mm 20mA | 1 |
Circuit has two parts:
1. Parking Sensor Transmitter:
Circuit uses IC 555 in astable mode and it controls IR LED to send fast blinking infrared light.
2. Parking Sensor Receiver:
This circuit uses the LM324 op-amp to receive the reflected IR signal and turn ON the LEDs based on how close the object is.
3. Transmitter Section:
IC1 555 timer works in astable mode and it makes square wave output, hence, this powers IR LED to send pulsing IR light.
Also, R1, R2, and C1 show the blinking speed using the following formula:
f = 1.44 / ((R1 + 2R2) × C1)
4. Receiver Section:
It has IR photodiode IR LED2 and IC2 LM324 op-amp, then IR LED2 sees bounced IR light and gives small voltage.
After that, IC2 boosts signal and LM324 IC works like comparator, which compares signal with voltages set by R7, R8, R9, R10.
Then based on signal strength it turns ON the LEDs to show the distance.
5. Distance Indication:
- LED1 (Green): Shows when object is far.
- LED2 (Yellow): Shows when object is getting closer.
- LED3 (Red): Shows when the object is very close.
Formulas:
DIY Parking Sensor Formula & Calculation
Transmitter Frequency (IC 555 in astable mode):
Formula:
f = 1.44 / ((R1 + 2×R2) × C1)
where,
- R1 is 10kΩ
- R2 is 1kΩ
- C1 is 1µF
How to Build:
To build a DIY Parking Sensor Circuit using IC 555 and IC LM324 follow the below steps for connections and assembling:
- First, collect all the parts as per the circuit diagram.
- Next, connect pin 1 of IC1 555 to GND.
- Join pin 2, 6, 7 of IC1 together.
- Then R1 goes from pin 7 to +12V and also R2 goes between pin 6 and 7.
- Now C1 positive goes to pin 2, 6, 7 and negative to GND.
- Further, IR LED1 positive goes to R3 from pin 3 to +12V.
- On IC2 LM324 connect pin 1 and 2 and add C2 and R4 in parallel.
- After that, connect pin 1 to pin 13 of IC2 through C3 positive side and negative to D1.
- Also, R5 and D2 go between C3 and D1 and GND.
- Next, R6 connects from R5 and D5 to +12V.
- Then Pin 3 of IC2 goes to GND.
- IR LED2 receiver connects between pin 2 of IC2 and GND.
- Pin 4 of IC2 to go to positive of 12V.
- Pins 6, 9, 13 of IC2 to R11 then go to GND.
- R7 from +12V go to pin 5 of IC2.
- R8 from pin 5 go to pin 10 of IC2.
- R9 from pin 10 go to pin 12 of IC2.
- R10 from pin 10 go to GND.
- C4 positive connect to pin 13 and negative to GND.
- Pin 7 connect to R12 and then to cathode of LED1 and anode go to +12V.
- Pin 8 goes to R13 and then to cathode of LED2 and anode goes to +12V.
- Pin 14 go to R14 and then to cathode of LED3 and anode goes to +12V.
- Finally, C5 positive go to +12V and negative go to GND.
Conclusion:
Overall, this DIY Parking Sensor Circuit using IC 555 and IC LM324 is cheap and easy to make.
Furthermore, IC 555 makes IR pulses and LM324 reads reflected signal and lights up LEDs to show how close the object is.
Also, we can upgrade this circuit with buzzer or display for better use.