Lets not waste any time and being with the practical tutorial. Fist remove the blue LED and the wires connected to it and then remove the LDR (Do not remove the connections only pull of LDR.)
1. Take the IR (Infra Red) LED and bend it to 90 degree and cut the legs as shown in the below image such that it's not too short or too long.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
2. Now connect the cathode terminal of IR LED to the gnd of breadboard power supply as shown in the following image.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
3. We skipped something in the above image we are sorry for that. You can see in the following image, connect pin no 1 of LM324 to the 21nth Pin of Microcontroller 8051 which is Port 2.0. And take an LED and place it on the Port 1.0 or Pin No 1 of microcontroller such that the cathode of LED is connected to the Port 1.0 of microcontroller and anode to the +vcc lane of the breadboard.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
4. Now lets continue with the IR LED. Take a 270 Ohm Resistor and place it between the anode terminal of IR LED and +5V Power lane of breadboard. Take the reference from following image and tally your connections.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
5. The breadboard setup will something look like this given in the following image. And we beleive you have already removed the LDR and Blue LED which we used in the previous chapter.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
6. Now Take the Photo diode or (IR Sensor) and then bend the legs of photo diode to 90 degree and cut the legs. Again we are warning, don't cut too short or too long. So just be careful.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
7. Now Just place it just in front of IR LED as shown in the below image. Again we already said that you only have to remove the LDR and not the connections attached with it.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
8. See here is the closer look of the setup. Just cross check your connections.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
9. Here is the whole view of the setup. Just make sure you have connected everything properly. If you have trouble, you can tally or compare it from the following image. And yes one more important thing. We had attached an LED to the 1st pin of LM324 such that the Anode of LED is connected to pin no 1 of LM324 and the cathode of LED is connected to the gnd of bread board lane as shown in the following image. And program the microcontroller. You will find the source code in the next chapter.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
10. When you are sure that you have got and connected everything perfectly then just power up the circuit with the battery. And put an obstruction between the IR LED and Photodiode and you will see that the LED attached to the microcontroller is glowing after the path has been blocked.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
11. And when the path is unblocked, the LED attached to the microcontroller will stop glowing. This is how this works.
![]() |
Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board |
And you have completed Interfacing LM324 Comparator IC with IR(Infra Red Light) Sensor and 8051 Microcontroller on Bread Board. Now jump to the next section to see the Demo working video of the circuit.
No comments:
Post a comment
Stuck Somewhere ? Comment Your Queries and Experts will Guide You.