17 October 2008

FT817 keypad for serious QRP /P contesting

In August 2008, after a productive VHF contest outside at 2700 masl (8800 feet asl), I felt the need to add an external keypad to my FT817 so that some controls would be readily accessible.

After a few months of software and hardware development I am announcing an alpha version of my keypad!

It is based on Atmel's ATtiny2313 microcontroller, uses very few components and does almost everything I wanted it to. Functions have been tailored to what I needed most last August, and the current release does the following:
  • direct frequency dial
  • mode change
  • VFO toggle
To be tested (tonight):
  • Presets QSYs to QRP frequencies (16 of them)
Still being studied:
  • Output power control
  • VOX on/off control
  • Meter mode control
but I am afraid these last will not fit into the 2313 program memory. So a modular approach might be suggested: functions are loaded as needed by the operator depending on the activity type (contesting, SOTA, ragchewing, ...).

Given the 4x4 keypad layout of the top table (see below), key functions are depicted below per each function.

Frequencies are entered with leading zero-padding to 100's of MHz: 007030 for 7030 kHz, 014060 for 14060 kHz, 0035C for 3500 kHz, 028# for 28 MHz, etc etc.
Mode switching is a star "*" followed by another key (see the Modes mapping).
Frequency presets are accessed with pound sign "#" followed by another key (see the Presets mapping).
VFO toggle is a single key press, as well as should be other functions under development (power, vox and meter).

Keypad Layout
1 2 3 A
4 5 6 B
7 8 9 C
* 0 # D

Main Menu
1 2 3 VFO Toggle
4 5 6 PWR cycle
7 8 9 VOX toggle
to Mode 0 to Presets Meter mode

Frequency dial
1 2 3 end
4 5 6 end
7 8 9 end
end 0 end end
014060 = 14060 kHz 144305 = 144305 kHz
014# = 14000 kHz 007C = 7000 kHz


1843 CW 3560 CW 7030 CW 10116 CW
14060 CW 18096 CW 21060 CW 28060 CW
14285 USB 50090 CW 21285 USB 28500 USB
144300 USB 50150 USB 432200 USB 29500 FM

A LED blinks at each keypress. The current consumption is about 10mA and the device can be powered directly from the ACC socket (where the commands are sent).

This keypad is not meant for a home-based station, where some excellent computer programs can do this and a lot more. It is an operator's aid when having fun on the field.

The same code might work with other Yaesu transceivers, like the FT857.