I've applied the following extension to my nanoKeyer:
- Memory bank selection
- smaller code changes
The Arduino nano board has a direct input to its 5V regulator. When applying 13.8V to this input, the regulator gets a little bit hot. This simple circuit
reduces the the input voltage about 3.2V, which helps to keep the regulator cooler. Additionaly a reverse-polarity protecion circuit and a rf-filter is provided.
Memory bank selection
On the current nanoKeyer circuit board, only three memory keys and the command key are available. Usually I work /qrp and /p so I don't want to reprogramm the memories constantly.
I've added a single-pole, three position switch to select te memories 1-3, 4-6 or 7-9 on the three memory buttons.
The sketch has to be updated, to support the switch settings correctly.
The updated sketch can be downloaded from here.
Code updated to the Say-Hi Feature
The Say-Hi feature is coded a little bit "ugly". I've updated the feature this way:
The keyer now sends my call during power-up even if the sidetone is switched of. The state of the transmitter key is also save correctly.