KX3/KX2 Memory Commander

Hi all KX3/KX2 users,

Yesterday I finally got to box a project I had made some time ago, and also found the time to write it up on my blog.
It’s a simple box with 6 buttons to trigger the 6 memories in the KX3, nothing more.
But it saves a key press (one key instead of two), and also avoids wear and tear on the buttons on the KX3.
Also, you can place the box closer with you, on your logbook or on your lap, etc …

I have made it self contained, with one Li-Ion cell and a charging/protection ciruit that can be charged with any cell-phone charger.
Total cost is under 10€ if you can find a suitable case in your junkbox.

With some minor changes in the commands, it can be made for a KX2 as well.
If you can’t figure it out yourself, contact me for help.

If needed, I could also change the code to switch between the two rigs, by holding a key when powering up (e.g. 1 = KX3, 2 = KX2).
Also thinking to expand the function of the buttons, short press = send once, long press = autorepeat message, but that wil have to wait a little … until I’m back from my SOTA trips.

I hope to use it soon for my activations in EA7 and EA5 … only two weeks from now … I can’t wait !
And of course I’ll bring it with me to the SOTA dinner in FH …

Luc - ON7DQ


Nice project Luc, thank you for sharing the details and code.


I just checked the KX3/KX2 programming manual, and only three small changes are needed to make this work for the KX2 as well.
See tables 8 and 8A in that manual.
Only the key codes for memories 4-5-6 are different.
KX3 : 28, 21 and 29 … for the KX2 these become : 16, 35 and 44.
I changed my code to have the keycodes in a String array, so commenting/uncommenting the appropriate line does the trick, and at the same time, I made the code much shorter.
New code is on my blog, see link above.

Can anyone out there with a KX2 verify that it works ?

I will make a “dual-rig” version when I find the time …

73 - Luc, ON7DQ