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Rs 232 - Troubleshooting

This page contains some tips in case you are having problems using this product.

Check wiring​

Ensure that the RS-232 breakout board is correctly wired to the Dasduino CONNECTPLUS:

  • TX on the Dasduino should connect to DIN1 (TTL Transmit) on the breakout board.
  • RX on the Dasduino should connect to ROUT1 (TTL Receive) on the breakout board.
  • Ensure that DOUT1 (RS-232 Transmit) and RIN1 (RS-232 Receive) are properly connected between both breakout boards.

Verify baud rate​

Both devices must use the same baud rate. If you’re using 9600, ensure that both the sender and receiver are configured with this value in their code.

Check common ground​

Both devices must share a common ground. Ensure that the GND pin of the RS-232 breakout board is connected to the GND pin of the Dasduino.

Test with a loopback​

To verify if each RS-232 breakout board is functioning:

  1. Connect TX to RX directly on the same breakout board.
  2. Send data from the Dasduino and check if it echoes back correctly.

Try running our examples​

If you’re confident that your wiring and configuration are correct, try running our RS-232 Communication Example.

Trim received data​

RS-232 communication often appends extra characters like spaces or newline characters (\n). Use .trim() in your code to clean up received strings before processing them.

Verify TX/RX connections​

Ensure that:

  • The sender’s TX pin is connected to the receiver’s RX pin.
  • The sender’s RX pin is connected to the receiver’s TX pin.

Check voltage levels​

Ensure that both devices are powered correctly:

  • The RS-232 breakout board should be powered with 5V from the Dasduino.
  • Ensure that there is no voltage mismatch between devices.

Debug with Serial Monitor​

Add debugging messages Serial.println() in your code to confirm whether data is being sent or received correctly.

Test LED circuit​

Manually test the LED by connecting it directly to 5V and GND through a resistor. If it doesn’t light up, there may be an issue with your LED or wiring.

Verify GPIO output​

Use a simple sketch to toggle the GPIO pin controlling the LED:

void setup() {
  pinMode(33, OUTPUT);
}

void loop() {
  digitalWrite(33, HIGH); // Turn on LED
  delay(1000);
  digitalWrite(33, LOW);  // Turn off LED
  delay(1000);
}