testapp1
========

On startup, transmit callsign, then start transmitting CW codes:

+--------+-----------+
| sign   | timeslot  |
+--------+-----------+
|  E     |     1     |
|  I     |     2     |
|  S     |     3     |
|  H     |     4     |
|  err   | permanent |
+--------+-----------+

CW is output on PB0, noninverted logic.

When SYNCn input on PB2 goes to zero, transmission stops, and the internal time is set to 0.

Modes
-----

When internal time < 10 minutes, transmit only sign without "MO", in short timeslots, then stay silent 30s.

If internal time >= 10 minutes, transmit "MO<sign>" for a full minute timeslot.