How to Use IRRECEIVER: Examples, Pinouts, and Specs

The TSOP85238 is an infrared (IR) receiver module manufactured by Vishay. It is designed to detect and demodulate infrared signals, typically used in remote control applications. This component converts modulated IR light signals into electrical signals that can be processed by microcontrollers or other electronic circuits. The TSOP85238 is optimized for 38 kHz carrier frequencies, making it compatible with most consumer remote controls.

• Remote control systems for TVs, audio systems, and set-top boxes
• Home automation systems
• Robotics and IR-based communication
• Proximity sensors and object detection

The TSOP85238 is a highly sensitive and reliable IR receiver module. Below are its key technical details:

The TSOP85238 has a 3-pin configuration as shown below:

1. Power Supply: Connect the V_cc pin to a regulated power supply (2.5 V to 5.5 V). Ensure the supply voltage is stable to avoid erratic behavior.
2. Ground Connection: Connect the GND pin to the ground of your circuit.
3. Output Signal: The OUT pin provides the demodulated digital signal. Connect this pin to a microcontroller input pin or other processing circuitry.
4. Decoupling Capacitor: Place a 100 µF capacitor between V_cc and GND to filter noise and stabilize the power supply.
5. IR LED Placement: Ensure the IR LED transmitting the signal is aligned with the TSOP85238's viewing angle (±45°).

• Avoid exposing the TSOP85238 to direct sunlight or strong ambient light, as this can interfere with its operation.
• Use a 38 kHz modulated IR signal for optimal performance.
• Keep the IR receiver away from high-frequency noise sources, such as switching power supplies.

Below is an example of how to connect the TSOP85238 to an Arduino UNO and read IR signals:

• Connect the TSOP85238's V_cc pin to the Arduino's 5V pin.
• Connect the GND pin to the Arduino's GND.
• Connect the OUT pin to Arduino digital pin 2.

#include <IRremote.h> // Include the IRremote library

const int RECV_PIN = 2; // Define the pin connected to the TSOP85238 OUT pin
IRrecv irrecv(RECV_PIN); // Create an IR receiver object
decode_results results;  // Variable to store decoded IR data

void setup() {
  Serial.begin(9600); // Initialize serial communication
  irrecv.enableIRIn(); // Start the IR receiver
  Serial.println("IR Receiver is ready to receive signals.");
}

void loop() {
  if (irrecv.decode(&results)) { // Check if an IR signal is received
    Serial.print("IR Code Received: ");
    Serial.println(results.value, HEX); // Print the received code in HEX format
    irrecv.resume(); // Prepare to receive the next signal
  }
}

• Install the IRremote library in the Arduino IDE before uploading the code.
• The received IR codes will be displayed in the Serial Monitor.

1. No Signal Detected:

   • Ensure the IR transmitter is emitting a 38 kHz modulated signal.
   • Check the alignment between the IR LED and the TSOP85238.
   • Verify the power supply voltage is within the specified range.

2. Erratic Behavior:

   • Add a decoupling capacitor (100 µF) between V_cc and GND.
   • Reduce ambient light interference by shielding the TSOP85238.

3. Short Reception Range:

   • Use a stronger IR LED or reduce the distance between the transmitter and receiver.
   • Ensure the IR LED is properly driven with sufficient current.

Q: Can the TSOP85238 detect continuous IR signals?
A: No, the TSOP85238 is designed to detect modulated IR signals at 38 kHz. Continuous signals will not be detected.

Q: What is the maximum distance for reliable operation?
A: The TSOP85238 can detect signals up to 45 meters, depending on the strength of the IR LED and environmental conditions.

Q: Can I use the TSOP85238 with a 3.3 V microcontroller?
A: Yes, the TSOP85238 operates within a supply voltage range of 2.5 V to 5.5 V, making it compatible with 3.3 V systems.

Q: How do I prevent interference from ambient light?
A: Avoid direct sunlight and use the TSOP85238 in a controlled environment. You can also use an IR filter to block unwanted light.

This concludes the documentation for the TSOP85238 IR receiver. For further details, refer to the Vishay datasheet.