A signal meter for the BBC micro:bit.

Run this on a couple of micro:bits, to measure their signal strength at different radio transmission powers and distances.

The left button cycles between display modes:

• Grid (default): The top row cycles when packets are received. The remaining four rows are used to display the received packet signal strength. The top left corner of this rectangle is -42 dB; the bottom right rectangle is -128dB. The last few samples are faded; this makes it easier to eyeball a trace of the signal strength history.

  In this mode, button B briefly displays the last received packet signal strength.

• The absolute value of the last received packet signal strength. The absolute value is used because the number is scrolled across the display, and the negative sign makes this take even longer.

• Transmission value (0 or 1), and receive value (0, 1, *). When the receive value is 0 or 1, the meter only attends to signals that match this value.

  In this mode, button B cycles among the values.

• Current radio transmission power.

  In this mode, button B cycles the radio transmission power from 0 to 7 and back to zero again.

Developed at Dinacon 2018.

MIT