Note
This is a web-version of a tutorial chapter embedded right into the XOD IDE.
To get a better learning experience we recommend to install the
desktop IDE or start the
browser-based IDE, and you’ll see the same tutorial there.
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.
Instructions #
Let’s make the alarm resettable.
- Add a
buttonnode. - Set the corresponding
PORT. - Link
PRSwith theRSTpin. - 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.