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Permanent Alarm

Screenshot of 203-permanent-alarm

Let’s extend the alarm device and make the LED stay enabled after trigerring even after the condition is no longer met. This is useful to signalize that something gone wrong even if it was not observed immediatelly.

When the value gets out of the range, the or node sends a pulse to the SET pin of the flip-flop node. So MEM returns True until we reset it, toggle it, or reboot the board.


Let’s make the alarm resettable.

  1. Add a button node.
  2. Set the corresponding PORT.
  3. Link PRS with the RST pin.
  4. Upload the program.

Heat or cool down the thermometer. Use the new button to turn the alarm off until the new trigger event is encountered.

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