1) Note all HW are way under 0.5%
 2) Note to set new freq a full restart of my windows 7 pc is needed.



tested are in bold

   100           5.5  
   125           6.88  
   150           8.25    .                   .31             Hw under 0.5%
   175           9.63                        .31 to .32    Hw under 0.5%

   193.75         10.66  
   196.88         10.83
  
   200         11.00                         .33 to .35  Hw under 0.5%


   206.25      11.34                          .36      4.85 volts.  .84 amps    11.34 gh    0 HW    with 34820 good.
                                                        .35    4.87 volts   .81 amps    11.38 gh   0 Hw with  85,000+ good
                                                        .34    4.87 volts   .79 amps----11.37 gh   1 Hw  for 9,000+ good shares  
                                   I look at this set of three tests at freq 206.25  and  realize I did not go low enough on the pots's setting


                                            
   212.50         11.69                 0.335 watts per gh  Hw 69 / 30912 shares  hash rate 11.73gh  power .81 amps 4.85 volts

  
   218.75          12.03                           just started  .84 amps 4.84 volts

  
   225.00         12.38  
   237.5         13.06  
   243.75      13.41  
   250           13.75  

And this show us that bitmain just dont care to make a good miner. They want to make profit. Sidehack take time to work with the chip and the result is awesome! 

Cant wait to see the board!  This is really nice 0.34 watt

https://bitcointalk.org/index.php?topic=1072425.msg11649161#msg11649161
winter is coming

Just a thought. . . .

If an MCU is going to be used to program/set CoreV (that has multiple A/D GPIO's) . . .
and if there was a current shunt on the incoming power connector (a circuit trace of a known length with infinitesimal resistance ) . . .
One would be able to calculate (or approximate) real-time power consumption (P=I*V in a DC circuit).

By knowing real-time power consumption, hashing rate, and a little coding, in theory, the device could have an "auto" mode that after a few iterations and time select the most cost effective clock and CoreV values. Precisely calculating and setting optimum W/GH/s.

Like stealing a page from the solar charge controller world, MPPT.
MPPT = Maximum Power Point Tracking.
OHPT = Optimum Hash Point Tracking.

If the MCU selected had a small amount of internal NVRAM, those values (CoreV and Clock Rate) could be stored to minimize the calculations after a power cycle.
After determining the optimum W/GH/s settings (saved to NVRAM), a count down timer could be used to set the periodicity for re-evaluation (say once an hour initially). This value and the std deviation/running average could also be used to "fine tune", stored in NVRAM, the periodicity of re-evaluation. This capability would help account for manufacturing tolerances and make the device aging optimized. The longer the chip has been operated the "smarter" it would become.

Creating a "smart" hashing board/device is/would be another feature set other products lack.

Probably not a cost effective solution on a stickminer, but on an 18+ chip version . . . .
That tech may be patentable, the MCU micro code is definitely copyrightable.
And may be worth something to a larger volume board manufacturer (Bitmain, Spondoolie, Avalon, etc.) or not and maintain a competitive advantage.

Just sayin' . . .

This thought line comes from a recent rather exhaustive (and ongoing) evaluation of Bitmain C1 operating parameters with a focus on the most profitable operating parameters.
Quite revealing with some of the conclusions being of the non-intuitive nature.



"Why Waltz when you can Rock'N'Roll." -- Unknown

Is it still open?

Great pictures and reporting so far, Phil.  I have one request/suggestion: for the cgminer screen caps hit d then i for widescreen reporting and it will show accepted/rejected/hw errors at the top to the right of WU.

Keep it up, great project to be following!

You do, just not as many as you would like.....