Unsolder SJ7

* if you had sectrig=VR or sectrig=auditrigger (and converting to secrig=HALL), than also

** open SJ7 solder-blob on the bottom, so LM1815pin12 output is DISconnected from the microcontroller input pin. This blob is on the bottom, close, to the line of FETs.

** actually this is the only step required if converting from sectrig=auditrigger (because that already has the HALL part of the circuit set up from EC36/13)

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* the instruction says: all 5 throughole pads in the middle must be empty

** note: jumpers are also like wires, might need to reconfigure if they were configured for VR

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Verification, R48, connecting the right signal to EC36/13 pin

* EC36/13 sectrig input pin should be connected to the proper side of R48 (the other side of R48 is +5V)

* With input disconnected: Should measure 3.7V or higher (absolute min 3.3V) at EC36/13 (or the CPU side of SJ7) when powered up and input not connected

* With a 1kOhm resistor between GND and input (instead of HALL sensor), DC voltage should measure between 0.5V and 1.5V

** eg. 870 mV: voltage divider equation: U=5V * R/(R + Rpullup)

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Verify in InputTrigger/TriggerLog