Mod 2: DDS VFO Firmware Version 1.1.

1. Added a new configuration option to enable the automatic saving of the current frequency and step. The save occurs 30 seconds after a new frequency is selected via the rotary encoder.
2. Changed the displayed 1KHz step to 1kHz.
3. Updated DDS VFO manual to include changes.

In version 1.0 the configured TX frequency in stored in EEPROM and loaded each time power is applied. As a result the LCD displayed frequency and the DDS output frequency are always the same at power up. Similarly the Step value is always 1kHz at power up.
Version 1.1 has an option to automatically save the current frequency and Step in EEPROM. This overwrites the TX frequency originally programmed during configuration.
So, at power up the displayed frequency and Step are the last ones set before earlier powering off.

The Atmega8 EEPROM is rated for a maximum of 100,000 write/erase cycles. If we were to simply save the frequency and Step each time the encoder changed frequency the allowed cycles would be quickly used up.
To get around this problem the save operation is only performed after an idle period of 30 seconds has elapsed since a frequency change. That is, the encoder must not change (alter frequency) for 30 seconds to allow a save to occur. To further reduce EEPROM writes the save is performed only once, so that if the frequency does not change for a long period the save is not continually repeated.
Using these techniques the EEPROM rating should never be exceeded.
When a save is being performed a small dot is flashed at the end of the frequency on the LCD.

In some cases this operation may not be desired and a new configuration option has been included so that it can be enabled or disabled.

Do I need it?
If you are happy with the operation of Version 1.0 then you do not need to upgrade.

How do I get it?
All new kits will be supplied with version 1.1.
If you have already purchased a kit you can receive the upgrade free of charge.
Simply email us and we will send via email the HEX file as an attachment. Of course you need to be able to reprogram the Atmega8 yourself.

Updated DDS VFO Manual.
An updated DDS VFO Manual issue 1.1 that outlines the operational changes is available for download in the Download page.