DuWayne S blogged about his stand alone simulated analog meter project:
Thinking about what values I would like to display, I came up with three basic items. A S-meter when in receive, and a power output display when in transmit. In transmit, I would also like to have the capability of measuring VSWR. Thinking about the switching functions required for this I will need one control line that monitors transmit/receive, this can come from the PTT or key line in the transceiver. Then I use a second control line to select either power or VSWR when the T/R line is in transmit. Another control line can do the same for the S-meter or some other display when in receive. Since this is based on a VU meter, I will use that for the secondary function in receive. Now looking at the signal lines I need to measure, they are the AGC line for S-meter, audio signal for VU meter. And in transmit, the forward and reverse power levels will take care of power and a computed VSWR reading.
See the full post at DuWayne’s Place blog.