05 November 2010

External display for transverter, diagram

Here is the schematic diagram for the external display based on ATmega168 (or mega48 or mega88 or mega328). Click to enlarge:

The component count is as low as possible. You may choose to take the supply from another source than the FT8x7 ACC port, such as a dedicated 9V battery.

You cannot leave out the two N.O. pushbuttons "[Up]" and "[Enter]" ("[Next]" on the diagram), but you can skip the LCD backlight control (mind the total supply current does not exceed 100mA, better less!).

This circuit is also the base for the keypad+display device I am still working on. The keyboard extension chip (PCF8574) will be connected to pins 4-5-6, so leave room for it on your board... in case you'll be interested in that device too.

"Release Candidate 1" ("RC1") firmware is available on request, until I publish it on my website.

Testers needed.

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