Update to the VK2ETA variation of Ian Lee's KD8CEC uBitx software #ubitx

John (vk2eta)

I have uploaded an update of both the Raduino and the ATU software in the folder  Variations on KD8CEC Software (by VK2ETA) + ATU sketch .

Is it targeted at portable and /PM operations. It is basically where I want it to be and I don't plan to add much further features unless they are of value to portable operations. 

If you want to use sections of code in your projects, follow the #ifdef/#endif segments that mostly enclose the sections of code of interest. I am happy to help with extraction of code if requested.

The software is organised in options that can be enabled/disabled (mostly) independently.

The key features added in this version are:
1. Reduction in libraries size by 1K byte (this allows for more features to be added in the limited memory of the Arduino).
2. Added a "Stock Standard" option for unmodified rigs wired as per hfsignals instructions.
3. Added a two adjustable levels supply voltage monitor with visual and audio indication. Level two will disable TX to protect the battery.
4. Added the WSPR beacon option from KD8CEC software version 1.061.
5. Changed logic for CW modes: frequency displayed is carrier frequency, with Rx frequency shifted up or down (CWL / CWU).
6. In split modes, the VFO A/B label and frequency change when going from Rx to Tx.
7. RIT display:  frequency is kept fixed, RIT is now shown as +/- frequency difference.
8. Added ALC levels for MAX level too. Used to be no attenuation.

All the best,

73, John (VK2ETA)


Is there a schematic somewhere for this extra arduino / atu?
Would love to build it.


John (vk2eta)

Hello Ad,

Yes there is. It is in the older folder below. The file is called ATU Schematics and pictures.
It is a servo based ATU, not a relay based one. It works nicely, a little slower than a relay version, but with memory tune, stored in EEPROM, it is quite ok. Have a look at the description here:
Schematics are here:

All the best,

73, John


Hello John,

Checked the file ATU schematics and and find only one picture an no schematic.
Is this right.

No hurry lots of other stuf to build.

Skip Davis

John, I only saw one picture of the radio display and no schematic or picture for the ATU also.

Skip Davis, NC9O

John (vk2eta)

Hello Skip,

Yes sorry, I didn't check the upload. 

I have uploaded the updated zip file in the new folder at

Here is a write up I did to describe the ATU:

I have also included here the two parts of the schematic. Part 1, the L-Network:

Control part:

Any question, ask. All the best,

73, John (VK2ETA)

John (vk2eta)

Uploaded a new version at this location:

Continuously looking for program size reduction to have as many features as possible concurrently in the Nano's memory.

Inspired by Ian Lee's KD8CEC version 1.701, I included a modified version of his TinyLCD library.

Compared to the complete default LiquidCrystal library this cut down version saves 452 bytes of program flash memory.

I made it into an object oriented class so it can be easily retrofitted into other projects as there are only two lines of code to change.

All the best,

73, John (VK2ETA)