Supplement [Digi-Key Follow Me Issue 2]

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Supplement [Digi-Key Follow Me Issue 2] [Copy link]

 

This post is to supplement the use of NUA7802 ADC module in [Digi-Key Follow Me Second Phase Submission Task](https://en.eeworld.com/bbs/thread-1263126-1-1.html), and is selected to be supplemented in Task 3. ### Task 3: Control WS2812B > Task requirements: Use buttons to control the display and color switching of the onboard `NeoPixel LED` - This task uses the onboard buttons, `NeoPixel LED` and additional ADC modules. The program logic is that the development board drives the ADC module to collect data. When the signal collected by the ADC module exceeds the threshold, the color of the onboard `NeoPixel LED` is changed. At the same time, when the button is detected to be pressed, the current screen display and the color of the onboard LED are fixed. When the button is pressed again, the collection continues. - Preparation: Because the ADC module has been added, you need to prepare the two libraries [adafruit-circuitpython-register](https://github.com/adafruit/Adafruit_CircuitPython_Register/releases) and [circuitpython-nau7802](https://github.com/adafruit/CircuitPython_NAU7802/releases/tag/2.1.1) and put them in the `/lib` directory of the development board. - The `code.py` code is as follows: ```python # Import required modulesimport board import time import displayio from digitalio import DigitalInOut, Direction, Pull import neopixel from adafruit_led_animation.animation.blink import Blink from adafruit_led_animation.color import JADE, BLACK, ORANGE, GOLD, OLD_LACE,RED from adafruit_display_text import label from adafruit_bitmap_font import bitmap_font from cedargrove_nau7802 import NAU7802 pixel_pin = board.NEOPIXEL num_pixels = 1 led_color = 0 # Initialize the pixel light pixels = neopixel.NeoPixel( pixel_pin, num_pixels, brightness=0.2, auto_write=False, pixel_order=neopixel.GRB ) # Configure the ADC module nau7802 = NAU7802(board.I2C(), address=0x2A, active_channels=1) # Define the functions required for ADC initialization def zero_channel(): nau7802.calibrate("INTERNAL") nau7802.calibrate("OFFSET") def read_raw_value(samples=2): sample_sum = 0 sample_count = samples while sample_count > 0: while not nau7802.ava ilable(): pass sample_sum = sample_sum + nau7802.read() sample_count -= 1 return int(sample_sum / samples) blink = Blink(pixels, speed=0.5, color=RED) btn = DigitalInOut(board.BOOT0) btn.direction = Direction.INPUT btn.pull = Pull.UP screen = board.DISPLAY text = displayio.Group() font = bitmap_font.load_ font("/font/fusion_pixel.pcf") text_0 = "RED" text_color = RED bt_status = 1 bt_cnt = 0 # Enable nau7802 digital and analog power enabled = nau7802.enable(True) time.sleep(2) # Calibrate and zero channel 1 nau7802.channel = 1 zero_channel() while True: # When a button is detected, determine the next operating status of the system if not btn.value: time.sleep(0.1) if not btn.value & bt_cnt: bt_status = not bt_status bt_cnt = 0 else: pass if bt_status: nau7802.channel = 1 value = read_raw_value() if value > 300 & value < 3000: text_color = JADE elif value < 300 & value > -3000: text_color = ORANGE elif alue < -3000 & value > -6000: text_color = GOLD elif value < -6000 & value > -8000: text_color = OLD_LACE elif value < -8000 & value > -10000: text_color = RED else:pass blink = Blink(pixels, speed=1, color=text_color) text_0 = "NAU7802 read is :\r\n %7.0f" %value text = displayio.Group() content_0 = label.Label(font, text=text_0 ,x=10, y=50, color = text_color, scale=3) text.append(content_0) screen.show(text) screen.refresh() time.sleep(0.1) # sleep for debounce # Execute LED flashing dynamic effect blink.animate() bt_cnt = 1 else: time.sleep(0.1) ``` - The effect is as follows: - Use your finger to approach the differential input terminal of the ADC module, the ADC sampling value will change, the LED color will turn red, and the current state will be fixed after pressing the button - Take your finger off the ADC module and press the button to let the system collect the value of the ADC module. The LED turns green with the ADC sampling value. Press the button again to fix the current value. Worth it