Hello. I am a total newbie and I was trying to make a noise detecting app, using bluetooth, an arduino board, and a sound sensing module in which the app automatically starts recording whenever the noise in the surroundings crosses a certain threshold. The app shows this error as soon as it opens. I'm not sure what the problem is. Could someone tell me what I'm doing wrong, and how to correct it? (Please mention how to rectify it using blocks as I'm a novice). Thank you. I'm attaching the source code, the error screenshot as well as the interface of the app.