Quality Control Checklist

Checklist

• [pass] Powers up over USB

• [pass] Programmable

• [pass] Serial

• [pass] RGB LED

• [mod] Switchable power cycling

• [pass] 2.4V boost converter

• [pass] 3.3V boost converter

• [pass] 5V boost converter

• [pass] VIN measure

• [pass] intADC

• [pass] exADC

• I2C 3.3V

• [pass] I2C 5V

• [pass] exADC MOSFET

• [pass] Battery level MOSFET

• [pass] intADC MOSFET

• Wake switch

• [mod] Voltage ORing VDD

• [pass] Voltage ORing 3.3V

Noted Defects

• Orientation of reset button still wrong

  • Mitigation: remove reset button

  • Alternate: may be possible to disconnect pads diagonally and get intended functionality

• Switchable power cycling resets on set low

  • Root cause: both ideal diodes are turning off at threshold

  • Mitigation: replace R21 with 357K

  • Fix: use mitigation or use ST pin on ideal diode for synchronized switching

• i2c hangs

  • this appears to be due to going low when 3v3 is switch off.

  • Fix: pullups should be agains VDD, not 3V3

Other Notes

• When VIN measure is disable, the ADC still reads a nonzero value

  • Suspect this is a floating voltage, test using current meter

• 5V boost has a very limited swing, around 100mV. Still, the ripple pattern is spiky. We could add a ferrite bead to smooth it. This could go in the place of SB27 to feed the the exADC with smooth 5v. To feed i2c we could place a bead in a similar solder bridge location.

• BOM included wrong pin count socket for J11 and J12