Bringing it all together

User Interface board

Today was the first time I wired everything together.

The major update for today was to use the SX1509 I/O expander with a 3x4 keypad.  Lessons learned included wiring the thing up correctly!  I was stumped for a while when the SX1509 stopped working which turned out to be due to the I²C pins being one pin off on the breadboard.  Close is not good enough!  ;-)

Control and UI boards

I wired up the volume and bandwidth digital pots and added support for updates from the UI board.  Of course I had an issue where my volume updates seem to work but the value was not retained by the control Arduino.  It turns out I needed to use the volatile keyword on a boolean flag used to indicate the end of a data packet (always use volatile for variables that are shared with an interrupt routine!).

I am now able to quickly change bands/modes and use the optical encoder to set the frequency, volume, and rx bandwidth.

So, what's next?

• Decide how to add 17 meters by using the 80m filter slot.
• Try the transmitter!
• Add a tx amplifier  (20 to 40 watts would be nice)
• Add tx post amp filters
• Add a T/R relay

Stay tuned!