C compile errors: stray '\200' in program and expected ')' before numeric constant

Question

I copied this program and am having trouble with the void downFrequency function (I think). This is for Arduino Uno. Here are the compiler errors: Compiling \'MY_dds\' for

Answer 1

The compiler is complaining that there are non-ASCII characters in your source file.

My octal fu is rusty, but it looks like UTF-8 to me. 342 200 223 is E2 80 93 which is Unicode "EN DASH." This code was given a minus sign makeover by a text editor with a degree in cosmetolegy.