pyopticon.built_in_widgets.spiciness_widget module

class pyopticon.built_in_widgets.spiciness_widget.SpicinessWidget(parent_dashboard, name, nickname)

Bases: GenericWidget

This is a silly demonstration of extending the GenericWidget class to make a widget that has no serial connection and only updates every few seconds. The superclass constructor is called with no_serial=True and update_every_n_cycles=3. The widget simply reports how spicy it’s feeling with a value randomly selected from a list.

The use_serial=False option is intended to allow the creation of widgets that do something besides poll a serial connection to update their information, but still have access to the data-logging and other machinery of the GenericWidget class. You might use this to:

  • Make a widget that communicates with a physical device through some means other than a Pyserial serial connection, e.g. a Python package provided by the instrument vendor.

  • Make a widget that reads the latest values from some instrument’s logfile on the computer. This can simplify post-experiment data fusion even if the entire instrument (e.g., a gas chromatograph) is far too complex to configure and run with a PyOpticon interface alone.

  • Make a standalone widget, e.g. a handy calculator, that has GUI elements but doesn’t interface with any physical devices.

The update_every_n_cycles option is meant to help interface with instruments that update less than once per second or take a long time to query. For example, a gas chromatograph will only log new concentration data every few minutes, while reading its logfile may be a slow operation, so polling it every 10 or 20 seconds is plenty and avoids gumming up the program with unnecessary reads. Similarly, if a device for some reason required serial queries to be spaced 200ms apart, and one needed to make 6 queries to extract all the data one wanted from it, beginning a sequence of 6 queries every second would overwhelm the instrument. Using update_every_n_cycles to start a sequence of 6 queries every other or every third second would avoid that issue.

Parameters:

  • parent_dashboard (pyopticon.dashboard.PyOpticonDashboard) – The dashboard object to which this device will be added

  • name (str) – The name that the widget will be labeled with, and under which its data will be logged, e.g. “Methane Mass Flow Controller”

  • nickname (str) – A shortened nickname that can be used to identify the widget in automation scripts, e.g. “CH4 MFC”

on_failed_serial_open(success)

Set readout to ‘no reading’ if initialization failed.

on_update()

Update the device by polling the serial connection.

on_serial_query()

“Nothing is done on a serial query for this device.

on_serial_read()

Updates the readout with a randomly selected level of spiciness. Returns True if this process was successful and False otherwise.

Returns:

True if the device updated itself successfully, False otherwise.

Return type:

bool

on_serial_close()

When serial is closed, set all readouts to ‘None’.