small messages for kilometres,

no internet or phone network

Not a beep. A chirp:

a diagonal line,

MeshCore's usual setting.

Where each chirp starts

jumps back to the bottom,

back to where it began.

seven bits per chirp.

each step up doubles it.

easier to pick out of noise.

a row of stripes:

why it reaches so far.

multiplies by a falling chirp,

a single tone:

one sharp spike.

a hundred times stronger