Difference between revisions of "Continuity Tester"

From Hackstrich
Line 13: Line 13:
  
 
== Rev001 Issues ==
 
== Rev001 Issues ==
* Holes for jacks are way too small
+
* Holes for jacks are way too small (addressed in ECO A)
 
* Footprint for trimmers fits, but is way way oversized
 
* Footprint for trimmers fits, but is way way oversized
 +
* LED footprints are backwards (anode/cathode swapped, addressed in ECO B)
 +
* Beeper/LEDs respond "analogly" due to the capacitor on the TRIGGER line
 +
** Need to add a Schmitt trigger or something similar to make this sound/look nicer
 +
* Current draw idle is a bit higher than I'd like, should try to optimize this further
 +
* Duty cycle control isn't really useful, should reevaluate need for it in Rev002
 +
== Rev001 ECOs ===
 +
* A - Trim legs on both jacks slightly to enable them to fit through the holes.
 +
* B - Mount LEDs upside down to work around the reversed footprint.
 +
 +
== Current Draw ==
 +
* Rev001 w/ ECO A+B
 +
** Idle - 465uA
 +
** Beeper - 1.5mA
 +
** LEDs - 3mA
  
 
[[Category:Current Projects]]
 
[[Category:Current Projects]]

Revision as of 16:45, 12 January 2018

I want to build a continuity tester that's fast, tiny, and can attach to a board I'm reversing so I don't need full multimeter when reversing boards away from a desk. The hardware files for this can be found on GitHub at sarahemm/continuity_tester.

Status

  • 2018-01-11: Received PCBs and parts, started assembling.
  • 2017-12-13: Completed PCB design, sent to OSH Park for manufacturing.
  • 2017-12-11: Started putting idea together after spending lots of hours reversing for the DMS project. BOM and schematic done, PCB layout in progress.

Features

  • Fast, latching to catch quick pulses as probe is dragged along multiple pins.
  • Visual/audio switchable options
  • Lasts a long time on a CR2032 or similar
  • Clips or magnets to a board I'm working on to save having another thing to put somewhere.

Rev001 Issues

  • Holes for jacks are way too small (addressed in ECO A)
  • Footprint for trimmers fits, but is way way oversized
  • LED footprints are backwards (anode/cathode swapped, addressed in ECO B)
  • Beeper/LEDs respond "analogly" due to the capacitor on the TRIGGER line
    • Need to add a Schmitt trigger or something similar to make this sound/look nicer
  • Current draw idle is a bit higher than I'd like, should try to optimize this further
  • Duty cycle control isn't really useful, should reevaluate need for it in Rev002

Rev001 ECOs =

  • A - Trim legs on both jacks slightly to enable them to fit through the holes.
  • B - Mount LEDs upside down to work around the reversed footprint.

Current Draw

  • Rev001 w/ ECO A+B
    • Idle - 465uA
    • Beeper - 1.5mA
    • LEDs - 3mA