How to Use Enecoder, 2/12 Series, CMOS, 2.4 V to 12 V, DIP-18: Examples, Pinouts, and Specs

The HT12E is a CMOS LSI encoder IC designed by Holtek Semiconductor for use in remote control system applications. It is capable of converting 12 bits of parallel data inputs into a serial output. When combined with a wireless transmitter and a corresponding decoder (such as the HT12D), it can serve as the basis for a simple wireless data link.

• Remote control systems for TVs, DVD players, and home automation
• Wireless doorbells and security systems
• Telemetry and remote sensing
• Robotics communication interfaces

• Operating Voltage: 2.4V to 12V
• Low Power Consumption
• Transmission Code: 12-bit
• Oscillator Frequency: 1MHz (typical)
• CMOS Technology for low power consumption

1. Connect VDD (pin 18) to a 2.4V to 12V power supply.
2. Connect GND (pin 9) to the ground of the power supply.
3. Set the address/data pins (A0-A7 and AD8-AD11) to the desired binary high/low configuration using switches or jumpers.
4. Connect an external resistor between OSC1 (pin 15) and OSC2 (pin 14) to set the oscillator frequency.
5. Connect TE (pin 16) to a control switch or microcontroller output pin to enable/disable transmission.
6. Connect DOUT (pin 17) to the data input of a wireless transmitter module.

• Ensure that the power supply voltage is within the specified range (2.4V to 12V).
• The address pins must match the corresponding decoder (HT12D) for the system to function correctly.
• Avoid long wires on the oscillator pins to prevent noise pickup.
• Use a decoupling capacitor close to the VDD pin to filter out power supply noise.
• The transmission enable (TE) pin should be kept high when not transmitting to reduce power consumption.

• No Output Signal: Ensure that the TE pin is pulled low to enable transmission. Check the power supply and oscillator frequency.
• Intermittent Operation: Verify that all connections are secure and that there is no interference from nearby electronic devices.
• Mismatched Address/Data: Confirm that the address/data settings on the encoder match those on the corresponding decoder.

• Double-check the power supply voltage and connections.
• Ensure that the oscillator frequency is set correctly according to the datasheet.
• Use a multimeter to verify the logic levels on the address/data pins.
• If using a wireless transmitter, confirm that it is functioning properly and within range.

Q: Can I use the HT12E without a microcontroller? A: Yes, the HT12E can be used with simple switches or buttons to set the address/data pins.

Q: What should I do if I experience interference in my wireless system? A: Try changing the address/data code to a different combination, and ensure that the antenna on the transmitter and receiver is optimized for the frequency of operation.

Q: How do I choose the resistor value for the oscillator? A: Refer to the HT12E datasheet for the formula to calculate the resistor value based on the desired oscillator frequency.

// Example code for interfacing HT12E with Arduino UNO for data transmission

#define TE_PIN 2 // Transmission Enable pin connected to Arduino pin 2

void setup() {
  pinMode(TE_PIN, OUTPUT);
  // Set TE_PIN as output to control the Transmission Enable of HT12E
}

void loop() {
  // Begin transmission by pulling TE low
  digitalWrite(TE_PIN, LOW);
  
  // Insert code here to set the address/data pins as needed
  
  // End transmission by pulling TE high
  digitalWrite(TE_PIN, HIGH);
  
  // Wait for some time before the next transmission
  delay(1000);
}

Note: This example assumes that the address/data pins are directly controlled by the user. In a practical application, these pins would be connected to switches or connected to other digital pins on the Arduino for more dynamic control.