Newbie Questions: USB Audio, Power On/Off

Jeff Anderson

Unaware of the existence of RigPi, I recently completed a Raspberry Pi project to be a remote computer for WSPR using my FT-1000D (if interested, see here).  

Just a couple of days ago I started looking into what it would take to make my Raspberry Pi a full remote-station controller.  And while googling, I discovered the RigPi

Because I already have a Raspberry Pi controlling my radio, it looks like the RSS software is just what I need to upgrade my Pi setup to full station control.  But before I make the purchase from MFJ, I had a few questions...

1.  Currently I am using a USB Audio Adapter for radio audio in/out.  Will the RSS software let me choose this USB Audio Adapter for audio I/O, or does it only use the RigPi Audio board?

2.  I'd like to remotely control station power.  As I understand it, the RigPi's "Keyer PTT" can perform this function (in conjunction with a separate controllable AC power accessory), but this requires that the Keyer IC installed, because it is this IC's PTT Output that controls the "Keyer PTT" signal for remote-control station power.  Correct?

3.  Assuming I'm correct regarding the Keyer IC and remote-control power, is the appropriate Keyer IC K1EL's "WinKeyer3"?  If not, which keyer chip is being used?

Many thanks for your help,

- Jeff, k6jca

Howard Nurse, W6HN

Hi Jeff,

Your blog post on what you've done with WSPR is excellent!

1. RSS will allow you to select an USB audio adapter.  You do not need the RigPi Audio board (it has some useful optional features).
2. RSS uses a GPIO pin for PTT.  You can interface that to an external relay for power control (see RigPi schematics).
3. The RSS Keyer uses K1EL's Winkeyer3 chip.

You can download the current image form the MFJ site or purchase it on a microSD card.  The download is cheaper.

73, Howard W6HN

Jeff Anderson

Thanks very much, Howard!

OK, so it is the "PTT" signal (gpio17) that is used for external power control.  Clearly I'm confused regarding the different PTT signals.  To help me understand...

1.  What is the purpose of "WK-PTT" (the PTT output from the WinKeyer) that is diode-or'd with "PTT" to drive the "PTT Out" jack on the keyer board?

2.  Are there any situations in which I might want to use the "PTT" signal for PTT operation (e.g. to drive Ring of the "Audio Out" jack) while at the same time needing it for external power control via the "PTT Out" jack?  Or are all cases mutually exclusive?

By the way, I've just purchased and downloaded RSS.  Now awaiting a 32 GB card to arrive.


- Jeff, k6jca

Howard Nurse, W6HN

Hi Jeff,

The WK-PTT line allows for setting PTT by means of a WK command.  It is therefore independent of RigPi's normal PTT control.  The hardware PTT is normally used for things like switching a linear during transmit.


Jeff Anderson

Thanks, Howard.  Sounds good.

- Jeff