About the YCCC SO2R Mini

The YCCC SO2R Mini is a Arduino-based computer-controlled device that provides computer controlled switching of two radios, managing audio routing of headphones and microphone, foot switch control of radio push-to-talk (PTT), and an emulation of the K1EL WinKeyer. Learn more at SO2R Mini.

SkookumLogger fully supports the Mini. This note describes some things you should know if you want to use the keyer emulation, and explains how to update the Mini firmware on macOS.

About the Mini Keyer

The WinKeyer emulation in the firmware provided with some Minis has several bugs: (1) the command for aborting sending does not stop sending until the next character space is encountered; (2) the command for disabling WinKeyer PTT does not disable WinKeyer PTT: (3) serial echo of each character is delivered too soon.

The correct behavior for the first bug is that abort interrupts the current character immediately. For example, when I tap the escape key immediately after the “K” in my call starts sending, the transmitted output should be a dit (not “K”). This matters when you have accidentally started to send the wrong message, and when you are using QSK and need to stop sending immediately to avoid transmitting at the same time as somebody who is calling you.

The consequence of the second bug is that the PTT output of the Mini is asserted during intra-character and inter-character spaces. This prevents QSK unless you unplug the PTT input from the Mini into the radio, but then your foot switch can't function.

The effect of the third bug is that when typing a call sign while it is being sent (this is called “type ahead”) you need to stay further ahead with your typing. For example, for the call DR1A, you must type the “A” before the “1” begins instead of before the “1“ ends.

These bugs are not fatal, and may not matter to you at all depending on your CW operating style. You can eradicate them by updating the Mini firmware to version 2020.02.18.02 or later, thanks to work by K3NG and JH5GHM.

Updating SO2R Mini Firmware

The procedure that is provided on the SO2R Mini web site is unusable for macOS. Here are the steps that I use (thanks JH5GHM for educating me about Arduino):

The value of CODE_VERSION just past the end of the huge initial comment block in the k3ng_keyer.ino file should be 2020.02.18.02 or later to be sure you have the software with the bug fixes.