Darkroom/Timer

The darkroom at the lab has a custom talking timer which understands multi-step processes and talks so that it is easy to use even in darkness.

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

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.

To generate new barcodes, you can use the Darkroom Timer Barcode Generator