95 lines
2.8 KiB
Python
95 lines
2.8 KiB
Python
"""
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This example will initialize the display using displayio and draw a bmp image
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background, and overlay text containing the value read from the on-board temperature sensor.
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User may press the A button to switch between celsius and fahrenheit units.
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Required libraries:
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* Adafruit_CircuitPython_Gizmo
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* Adafruit_CircuitPython_ST7789
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* Adafruit_CircuitPython_Display_Text
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* Adafruit_CircuitPython_CircuitPlayground
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"""
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import time
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from adafruit_circuitplayground import cp
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import displayio
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import terminalio
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from adafruit_display_text import label
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from adafruit_gizmo import tft_gizmo
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display = tft_gizmo.TFT_Gizmo()
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# text scaling factor
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TEXT_SCALE = 2
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# previous iteration button value
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old_a_val = cp.button_a
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# boolean for current unit type
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show_c_units = True
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# function to convert celsius degrees to fahrenheit
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def c_to_f(c_val):
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return (c_val * 9 / 5) + 32
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# Open the background image file
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with open("/thermometer_background.bmp", "rb") as bitmap_file:
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# Setup the file as the bitmap data source
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bitmap = displayio.OnDiskBitmap(bitmap_file)
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# Create a TileGrid to hold the bitmap
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tile_grid = displayio.TileGrid(bitmap, pixel_shader=displayio.ColorConverter())
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# Create a Group to hold the TileGrid
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group = displayio.Group()
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# Add the TileGrid to the Group
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group.append(tile_grid)
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# variable with initial text value, temperature rounded to 2 places
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text = "%.2f C" % (round(cp.temperature, 2))
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# Create a Group for the text so we can scale it
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text_group = displayio.Group(max_size=1, scale=TEXT_SCALE, x=0, y=0)
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# Create a Label to show the initial temperature value
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text_area = label.Label(terminalio.FONT, text=text, color=0xFFFFFF)
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# Set the anchor_point for center,top
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text_area.anchor_point = (0.5, 0.0)
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# Set the location to center of display, accounting for text_scale
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text_area.anchored_position = (240 / (2 * TEXT_SCALE), 240 / (2 * TEXT_SCALE))
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# Subgroup for text scaling
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text_group.append(text_area)
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# Add the text_group to main Group
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group.append(text_group)
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# Add the main Group to the Display
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display.show(group)
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# Loop forever
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while True:
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# set current button state to variable
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cur_a_val = cp.button_a
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if cur_a_val and not old_a_val: # if the button was released
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print("Just released")
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# flip the units boolean to the opposite value
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show_c_units = not show_c_units
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if show_c_units:
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# Update the text
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text_area.text = "%.2f C" % (round(cp.temperature, 2))
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else: # show f units
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# Update the text
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text_area.text = "%.2f F" % (round(c_to_f(cp.temperature), 2))
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# set previous button value for next time
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old_a_val = cur_a_val
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# Wait a little bit
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time.sleep(0.2)
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