Moves the console_menu.py demo from python repo (#46)

Moves the console menu demo from python-lang/utils to the demos. This demonstrates LEDs, console and buttons.

Author: gideongrinberg

robots/misc/console_menu.py

@@ -0,0 +1,200 @@
+#!/usr/bin/env micropython
+from time import sleep
+from sys import stderr
+from os import listdir
+from ev3dev2.button import Button
+from ev3dev2.console import Console
+from ev3dev2.led import Leds
+from ev3dev2.sensor import list_sensors, INPUT_1, INPUT_2, INPUT_3, INPUT_4
+
+
+"""
+Used to create a console menu for switching between programs quickly
+without having to return to Brickman to find and launch a program.
+Demonstrates the EV3DEV2 Console(), Led(), and Button() classes.
+"""
+
+
+def get_positions(console):
+    """
+    Compute a dictionary keyed by button names with horizontal alignment,
+    and column/row location to show each choice on the EV3 LCD console.
+    Parameter:
+    - `console` (Console): an instance of the EV3 Console() class
+    returns a dictionary keyed by button names with column/row location
+    """
+
+    midrow = 1 + console.rows // 2
+    midcol = 1 + console.columns // 2
+    # horiz_alignment, col, row
+    return {
+        "up": ("C", midcol, 1),
+        "right": ("R", console.columns, midrow),
+        "down": ("C", midcol, console.rows),
+        "left": ("L", 1, midrow),
+        "enter": ("C", midcol, midrow)
+    }
+
+
+def wait_for_button_press(button):
+    """
+    Wait for a button to be pressed and released.
+    Parameter:
+    - `button` (Button): an instance of the EV3 Button() class
+    return the Button name that was pressed.
+    """
+    pressed = None
+    while True:
+        allpressed = button.buttons_pressed
+        if bool(allpressed):
+            pressed = allpressed[0]  # just get the first one
+            while not button.wait_for_released(pressed):
+                pass
+            break
+    return pressed
+
+
+def menu(choices, before_run_function=None, after_run_function=None):
+    """
+    Console Menu that accepts choices and corresponding functions to call.
+    The user must press the same button twice: once to see their choice highlited,
+    a second time to confirm and run the function. The EV3 LEDs show each state change:
+    Green = Ready for button, Amber = Ready for second button, Red = Running
+    Parameters:
+    - `choices` a dictionary of tuples "button-name": ("mission-name", function-to-call)
+        Example:
+            choices = {
+                # "button-name": ("mission-name", function-to-call)
+                # or "button-name": ("mission-name", lambda: call(x, y, z))
+                "enter": ("CAL", lambda: auto_calibrate(robot, 1.0)),
+                "up": ("MI2", fmission2),
+                "right": ("MI3", fmission3),
+                "down": ("MI4", fmission4),
+                "left": ("MI5", fmission5)
+            }
+        where fmission2, fmission3 are functions;
+        note don't call them with parentheses, unless preceded by lambda: to defer the call
+    - `before_run_function` when not None, call this function before each mission run, passed with mission-name
+    - `after_run_function` when not None, call this function after each mission run, passed with mission-name
+    """
+
+    console = Console()
+    leds = Leds()
+    button = Button()
+
+    leds.all_off()
+    leds.set_color("LEFT", "GREEN")
+    leds.set_color("RIGHT", "GREEN")
+    menu_positions = get_positions(console)
+
+    last = None  # the last choice--initialize to None
+
+    while True:
+        # display the menu of choices, but show the last choice in inverse
+        console.reset_console()
+        for btn, (name, _) in choices.items():
+            align, col, row = menu_positions[btn]
+            console.text_at(name, col, row, inverse=(btn == last), alignment=align)
+
+        pressed = wait_for_button_press(button)
+
+        # get the choice for the button pressed
+        if pressed in choices:
+            if last == pressed:   # was same button pressed?
+                console.reset_console()
+                leds.set_color("LEFT", "RED")
+                leds.set_color("RIGHT", "RED")
+
+                # call the user's subroutine to run the mission, but catch any errors
+                try:
+                    name, mission_function = choices[pressed]
+                    if before_run_function is not None:
+                        before_run_function(name)
+                    mission_function()
+                except Exception as ex:
+                    print("**** Exception when running")
+                    print(ex)
+                finally:
+                    if after_run_function is not None:
+                        after_run_function(name)
+                    last = None
+                    leds.set_color("LEFT", "GREEN")
+                    leds.set_color("RIGHT", "GREEN")
+            else:   # different button pressed
+                last = pressed
+                leds.set_color("LEFT", "AMBER")
+                leds.set_color("RIGHT", "AMBER")
+
+
+if __name__ == "__main__":
+
+    # This is the main program to demonstrate the console menu logic above.
+    #
+    # Define functions that represent different missions
+    # Note: these can be imported from different modules (files)
+    # and use lambda notation to defer the function call
+    # i.e. lambda : call(a, b, c)
+
+    def calibrate():
+        """ Placeholder for call to your calibration logic to set the black and white values for your color sensors """
+        print("calibrating...")
+        sleep(1)
+
+    def show_sensors(iterations):
+        """ Show the EV3 sensors, current mode and value """
+        sensors = list(list_sensors(address=[INPUT_1, INPUT_2, INPUT_3]))   # , INPUT_4
+        for _ in range(iterations):
+            for sensor in sensors:
+                print("{} {}: {}".format(sensor.address, sensor.mode, sensor.value()))
+                sleep(.5)
+        sleep(10)
+
+    def mission1():
+        print("mission 1...")
+        sleep(1)
+
+    def mission2():
+        print("mission 2...")
+        sleep(1)
+
+    def mission3():
+        print("mission 3...")
+        sleep(1)
+        # for testing when a function generates an error
+        raise Exception('Raised error')
+
+    # Define the functions to be called before and after each run.
+    # Functions will be called with the mission_name as the argument.
+    # Useful for resetting motor positions between runs, etc.
+
+    def before(mission_name):
+        print("before " + mission_name)
+
+    def after(mission_name):
+        print("after " + mission_name)
+        sleep(1)
+
+    # Define the buttons, mission names, functions for the console menu.
+    # Key is the button assignment: one of "enter", "up", "right", "down", "left"
+    # Note the "backspace" button interrupts the program and returns to Brickman
+    # Example:
+    # CHOICES = {
+    #     # "button-name": ("mission-name", function-to-call)
+    #     # or "button-name": ("mission-name", lambda: call(x, y, z))
+    #     "up": ("MI1", mission1),
+    #     "right": ("MI2", mission2),
+    #     "left": ("MI3", mission3),
+    #     "down": ("SHOW", lambda: show_sensors(5)),
+    #     "enter": ("CAL", calibrate)
+    # }
+    # menu(CHOICES, before_run_function=before, after_run_function=after)
+
+    CHOICES = {
+        "up": ("MI1", mission1),
+        "right": ("MI2", mission2),
+        "left": ("MI3", mission3),
+        "down": ("SHOW", lambda: show_sensors(5)),
+        "enter": ("CAL", calibrate)
+    }
+
+    menu(CHOICES, before_run_function=before, after_run_function=after)