Difference between revisions of "Talking Darkroom Timer"

From Hackstrich
(Created page with "I got tired of having to mess with darkroom timers in the dark while processing colour prints in trays, so designed and built a timer that understands entire processes and wal...")
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Revision as of 14:37, 7 September 2016

I got tired of having to mess with darkroom timers in the dark while processing colour prints in trays, so designed and built a timer that understands entire processes and walks you through them step-by-step with speech. The timer reads process information from paper instruction sheets using Aztec 2D barcodes and then times each required step.

Components

  • Timer itself, located above the left side of the sink near the ceiling
    • Raspberry Pi 2
    • Adafruit LCD Plate
    • Proto Plate with RS232 level shifter for barcode reader
  • Speaker above the timer
  • 2D barcode reader mounted on the shelf aimed at the wall
  • Control panel below the sink with the following controls:
    • Large green SELECT button
    • Navigation left/right control
    • Active/Standby toggle switch
  • Aztec Code barcodes on each process sheet, which contain all timing information

Usage Procedure

  • Set the Active/Standby switch on the timer control panel to Active
  • Scan the barcode for the process you want under the crosshairs that appear on the wall
    • Barcodes can be found on instruction sheets for each process that are hung up behind the door.
  • Double check that the timer is displaying the process you want to run, and press the big green SELECT button
  • The timer may ask if you want to adjust the time for specific steps.
    • If you don't, just press SELECT.
    • If you do, use the navigation buttons to change to Yes and press SELECT.
  • The timer will show and read out each step as it's ready.
  • Press SELECT to start each step.
    • If you want to run a different step instead, use the navigation buttons to scroll through.
  • To abort a step in progress, hold the SELECT button until you hear a buzzer.

Other Information