Canvas graph not plotting

MIT App Inventor Help
5

This is how you are sending your temperature:


void loop() {
  // Read the analog value from LM35
  int analogValue = analogRead(lm35Pin);

  // Convert to voltage (assuming 5V and 10-bit ADC)
  float voltage = analogValue * (5.0 / 1023.0);

  // Convert voltage to temperature in Celsius
  float temperatureC = voltage * 100;

  // Send temperature via Serial (Bluetooth)
  Serial.println((int)temperatureC);

  // Display temperature on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperatureC, 1); // Show 1 decimal place
  lcd.print(" C");

  delay(1000);  // Update every 1 second
}

You are sending one number per line, with nothing extra on the line.

This is how you are trying to receive and process your messages:

bad
bad1624×1652 411 KB

You are looking for non-existent commas.
You also forgot to increment x for your graph, so your graph is just a vertical line all the way at the left.

This draggable block should address both problems:

good
good1624×1622 405 KB

P.S. I did not address the possible need to address vertical scaling, in case there is a big mismatch between the range of Y pixel ranges and incoming temperature values.

Also, there is a hook in the AI2 GraphData component to read such a Bluetooth data stream and plot it directly, with automatic scaling.

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