Hello, I am a beginner and trying to use the HT12E encoder to control an IR LED, but I am having trouble. The IR LED stays ON even when no button is pressed. I need help troubleshooting.

• Circuit Setup:
  • HT12E Pin 17 → IR LED Signal Pin
  • IR LED Module (HW-489) → Connected to 5V and GND
  • HT12E Data Pins (Pin 10 to 13) → Connected to 5V
  • Button → Connected between Pin 10 and GND
  • Oscillator Resistor (1MΩ) → Connected between Pins 15 and 16
• Troubleshooting Done:
  • Measured Pin 17 voltage → 1.4V to 1.5V fluctuating
  • Tried replacing HT12E chip, IR LED module, and resistors
  • Removed the button but the LED still stays ON
  • Used a multimeter to check connections
• Questions I Need Help With:
  • Is my wiring correct for controlling an IR LED with HT12E?
  • Why is Pin 17 output not changing when pressing a button?
  • Do I need additional pull-up or pull-down resistors?
  • Should I try a normal IR LED instead of the HW-489 module?

 

Welcome to AAC!

I like to build a very small component test circuit to ensure that the components actually work. Also, double check the frequencies of your emitter and receiver LEDs. They do come in different frequencies.

 

Is my wiring correct for controlling an IR LED with HT12E?

This is the wiring diagram from the spec sheet. Note the pin numbers.
All address and data pins are normally pulled to ground.

 

If you have a digital multimeter you should measure the voltage across one or more of the switches. The voltage should be close to the pin 18 supply voltage. Do you have an actual data sheet for that IC device?? Have you read and understood the data sheet??

 

I did not build the ht12d side, so there is no mismatch, and I tested all four buttons. I even checked different types of buttons and directly wired to check the IR LED, but it was still on. I also tried to use the LED model, but even the LED model did the same thing same led to a video that contained ht12 and ir setup or the same thing close to it thanks

 

You seem to have transmission enable straped to ground. It should be connected to the push button. Read the first paragraph on page 5 of the data sheet. Pulsing AD8 -AD11 to ground only initiates a transmission on a HT12A. I have never used an HT12 and have only skimmed the data sheet so my understanding may be wrong.
Les.