Hi Roy,

Thanks for the comments. I hope that you are soon able to build a similar setup for yourself.

The SW and FM enable signals are useful for the software in autonomous mode. Each time the radio receiver changes modes, e.g. from MW to FM, the Si4734 is rebooted to the new mode. (The FM and AM signal processing code cannot all fit into RAM at the same time.) So, in order to defeat soft-mute, the new MCU software has to reprogram the parameters each time there is a mode switch. By wiring in the antenna enabling signals, I can detect this. Of course this also enables different programming in different modes.

The debug lead can be used with the ToolStick base adapter and other MCU programming/debug tools sold by Silabs. All Silabs MCU have a two-wire (plus ground) in-system debugging interface. In addition to programming the flash memory, this interface works with the free IDE software for interactive source-level debugging. You can run code, stop a breakpoints, view/change registers, etc. I wired the extra lead so I can access the port by only removing the back of the radio. It would be nice to find another "stealth" location for it. I've thought about somewhere under the battery door or the kick-stand, but space is very tight.

I'm still exploring whether Silicon Labs can make the GUI software generally available. I hope so. But in the meantime, I've started working on an alternative, adapting code that is already publicly available. I finally came up with an interface on the PC side that doesn't need a full-blown C++/C#/.NET development system. Basically, I have four functions that easily compile with "MinGW", a freeware C compiler. Above that, I can build everything with the Tcl scripting language. (Tcl may not be to everyone's liking, but the same basic C code should be "glueable" into other frameworks and provides all the USB functionality that is required.) On the USB side, the radio looks like a standard HID device, which uses device drivers that are already built-into Windows, Linux, and MacOS.

Let me know when you get your ToolStick. I can send you more details about the interface and software.

-Scott-