While using the code provided in the Arduino Pro Tutorials for BlinkRedLed_M7, I encountered a compilation error:

Compilation error: stray ‘302円’ in program

This error appears due to an invisible Unicode character in the comment on line 11:

digitalWrite(LEDR, HIGH); // turn the LED off by making the voltage HIGH

To fix this, you can delete the comment on line 11 and retype it, ensuring no hidden characters are present.

Steps to Reproduce

1. Copy the code from the tutorial and paste it into the Arduino IDE.
2. Attempt to compile.
3. Observe the error related to the stray character 302円.

Suggested Solution

Please check the code on the tutorial page for any hidden Unicode characters and remove them. Retyping the comment manually on line 11 seems to resolve the issue.

Environment

• Board: Specify board, e.g., Arduino Portenta H7
• Tutorial Link: https://docs.arduino.cc/tutorials/portenta-h7/dual-core-processing/

Additional Context:

This error can be confusing for users, especially those new to Arduino, as it’s caused by invisible characters that are not easily noticeable.