X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=Notebook;h=ef2464787ee61a668a0737d331be911366c45ed7;hb=7e90a22a80b6d38e5d0fef6f1682ceab316696e5;hp=c9798650b4ed7096151608591c88ec7a1bea2f51;hpb=b752bdd1687668ff5e7f5d642b0c1cc02bb77da1;p=hw%2Fquantimotor

diff --git a/Notebook b/Notebook
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+++ b/Notebook
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 - move switches down box so they aren't spread out into gasket rim area
 
+- add another 2-pin header to PA8 (MCO) so we can sample the master clock to
+  calibrate the SOC oscillator, which means moving the RED RF strength LED to
+  some other gpio line
+
+2019.10.31
+- The more I think about this project, the more I want to go back to a board
+  that just does one each load cell and pressure sensor.  I just haven't ever
+  actually used anything else.
+
+  Discussion with Joe Bowen made it clear that if I were to design such a 
+  board so that it could take option cards, and/or had just a pile of basic
+  analog inputs and maybe switch outputs available, that doing other stuff
+  could be fun, and we'd "grow the system as we need to".  Every time I tried
+  to pin him down on specs, all I got was vagueness.
+
+2020.01.18
+- Maybe the right answer is to move to the ADS131A02 which is the 2-channel
+  version of the acquisition chip, and costs less.  That would support one
+  pressure sensor and one load cell.  Then make it possible to add on other
+  acquisition boards somehow.
+
+2020.10.20
+- sticking with the ADS131A04 and routing the extra two inputs to the header
+  means that supporting 2 burn wires for the strand burner daughter card is
+  dead simple.  it also means that adding a second load cell and pressure
+  sensor if required on a daughter card would also be dead simple.
+
+- for strand burner, I need a daughter card that provides a high-side switch
+  for pyro power (since I need a common ground through the system), and has
+  resistors for 2 ADC inputs hooked to burn wires.  Bring this all out through
+  a 5-pin connector to the outside that hooks to the strand burner end.  We'd
+  also use the existing pressure sensor channel, but not use the load cell.
+
+  So, firmware wants to log all 4 analog inputs all the time.  For a test
+  stand run, only the pressure sensor and load cell are relevant.  For strand
+  burner, pressure sensor and the two burn wires are relevant.
+
+- for Jamie / Estes, I need a daughter card that adds at least 4 thermistor
+  inputs, and support for their Sony camera trigger thing.
+
+- 40 pin header and mating female connector for daughter cards w/q1 pricing
+
+	header	Sullins PRPC020DAAN-RC	DK S2011EC-20-ND	0.90	
+	mating	Sullins PPPC202LFBN-RC	DK S7123-ND		2.38	
+
+- high-side switch for strand burner daughter card.  This is an 8-SO part
+  good to 28V and 21A, 50 mOhm on resistance.  Should be trivial to make 
+  work on a 2-layer PCB
+
+	ST's VN7050ASTR, DK 497-15993-1-ND, 1.58
+
+  Means we need multiple header pins carrying pyro voltage to get enough
+  current, since the header spec is 3A per pin.  2-4 pins each for v_pyro
+  on the pin 1 end, and gnd on the other end should do.
+
+- for strand burner daughter, use CUI TB003-500-P06BE 6-position 5mm pitch
+  screw terminal strip, supports 14-26 AWG wire, 10A per pin continuous,
+  DK 102-6165-ND, $1.01 q1
+