64 lines
2.0 KiB
Python
64 lines
2.0 KiB
Python
# This example takes the temperature from the Pico's onboard temperature sensor, and displays it on Pico Explorer, along with a little pixelly graph.
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# It's based on the thermometer example in the "Getting Started with MicroPython on the Raspberry Pi Pico" book, which is a great read if you're a beginner!
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import st7789
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import machine
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import utime
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# Pico Explorer boilerplate
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display = st7789.ST7789(st7789.DISPLAY_PICO_EXPLORER, rotate=0)
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display.set_palette_mode(st7789.PALETTE_USER)
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display.set_backlight(1.0)
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WIDTH, HEIGHT = display.get_bounds()
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# reads from Pico's temp sensor and converts it into a more manageable number
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sensor_temp = machine.ADC(4)
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conversion_factor = 3.3 / (65535)
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BLACK = display.create_pen(0, 0, 0)
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WHITE = display.create_pen(255, 255, 255)
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RED = display.create_pen(255, 0, 0)
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GREEN = display.create_pen(0, 255, 0)
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BLUE = display.create_pen(0, 0, 255)
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i = 0
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while True:
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# the following two lines do some maths to convert the number from the temp sensor into celsius
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reading = sensor_temp.read_u16() * conversion_factor
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temperature = round(27 - (reading - 0.706) / 0.001721)
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# this if statement clears the display once the graph reaches the right hand side of the display
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if i >= WIDTH + 1:
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i = 0
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display.set_pen(BLACK)
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display.clear()
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# chooses a pen colour based on the temperature
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display.set_pen(GREEN)
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if temperature > 20:
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display.set_pen(RED)
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if temperature < 13:
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display.set_pen(BLUE)
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# draws the reading as a tall, thin rectangle
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display.rectangle(i, HEIGHT - (temperature * 6), 6, HEIGHT)
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# draws a white background for the text
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display.set_pen(WHITE)
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display.rectangle(1, 1, 65, 33)
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# writes the reading as text in the white rectangle
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display.set_pen(BLACK)
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display.text("{:.0f}".format(temperature) + "c", 3, 3, 0, 4)
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# time to update the display
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display.update()
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# waits for 5 seconds
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utime.sleep(5)
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# the next tall thin rectangle needs to be drawn 6 pixels to the right of the last one
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i += 6
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