feat(apds9960): Add OLED color lamp example.

Author: Kaan Ozen

lib/apds9960/examples/color_lamp.py

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+"""Color lamp example using APDS9960 and SSD1327 OLED.
+
+Detects the color of an object placed near the APDS9960 sensor.
+Includes an auto-calibration phase for ambient room light.
+Displays the dominant color and raw RGBC values on a round OLED layout.
+The background brightness matches the ambient light intensity dynamically.
+"""
+
+from time import sleep_ms
+
+import ssd1327
+from apds9960 import uAPDS9960 as APDS9960
+from machine import I2C, SPI, Pin
+
+# Layout Constants
+MIN_CLEAR = 10
+TITLE_Y = 24
+TITLE_X = 28
+COLOR_Y = 40
+COLOR_X = 44
+GRID_ROW1_Y = 70
+GRID_ROW2_Y = 90
+GRID_COL1_X = 20
+GRID_COL2_X = 72
+
+# Calibration Constants
+CALIB_TEXT1_X = 12
+CALIB_TEXT1_Y = 54
+CALIB_TEXT2_X = 16
+CALIB_TEXT2_Y = 74
+CALIB_COLOR = 15
+CALIB_BASELINE = 50
+CALIB_SAMPLES = 30
+CALIB_DELAY_MS = 100
+CALIB_BUFFER_DIVISOR = 10
+
+# Hardware Initialization
+i2c = I2C(1)
+apds = APDS9960(i2c)
+apds.enable_light_sensor()
+spi = SPI(1)
+dc = Pin("DATA_COMMAND_DISPLAY")
+res = Pin("RST_DISPLAY")
+cs = Pin("CS_DISPLAY")
+display = ssd1327.WS_OLED_128X128_SPI(spi, dc, res, cs)
+
+print("=======================")
+print("      Color Lamp       ")
+print("=======================")
+print("Press Ctrl+C to exit.")
+
+try:
+    # Auto-Calibration Phase
+    print("Calibrating ambient light... Leave the sensor uncovered.")
+    display.fill(0)
+    display.text("Calibrating...", CALIB_TEXT1_X, CALIB_TEXT1_Y, CALIB_COLOR)
+    display.text("Do not cover", CALIB_TEXT2_X, CALIB_TEXT2_Y, CALIB_COLOR)
+    display.show()
+
+    max_clear_calib = CALIB_BASELINE  # Baseline minimum
+    # Sample light for about 3 seconds
+    for _ in range(CALIB_SAMPLES):
+        c = apds.ambient_light()
+        max_clear_calib = max(max_clear_calib, c)
+        sleep_ms(CALIB_DELAY_MS)
+
+    # Add a small buffer to the max calibration so it doesn't max out too easily
+    MAX_CLEAR = max_clear_calib + (max_clear_calib // CALIB_BUFFER_DIVISOR)
+    print("Calibration complete. MAX_CLEAR set to:", MAX_CLEAR)
+    sleep_ms(500)
+
+    # --- Main Loop ---
+    while True:
+        # Read RGBC values from the sensor
+        c = apds.ambient_light()
+        r = apds.red_light()
+        g = apds.green_light()
+        b = apds.blue_light()
+
+        # Determine background greyscale intensity (0 to 15)
+        clamped_c = max(0, min(c, MAX_CLEAR))
+        bg_color = (clamped_c * 15) // MAX_CLEAR
+
+        # Determine text contrast (Dark text on light background, and vice-versa)
+        text_color = 0 if bg_color > 7 else 15
+
+        # Determine dominant color
+        dominant_name = "DARK"
+        if c > MIN_CLEAR:
+            if r > g and r > b:
+                dominant_name = "RED"
+            elif g > r and g > b:
+                dominant_name = "GREEN"
+            elif b > r and b > g:
+                dominant_name = "BLUE"
+            else:
+                dominant_name = "MIXED"
+
+        # Drawing Phase
+        display.fill(bg_color)
+
+        display.text("Dominant:", TITLE_X, TITLE_Y, text_color)
+        display.text(dominant_name, COLOR_X, COLOR_Y, text_color)
+
+        # Draw Raw RGBC values in a 2x2 Grid
+        display.text("R:{}".format(r), GRID_COL1_X, GRID_ROW1_Y, text_color)
+        display.text("G:{}".format(g), GRID_COL2_X, GRID_ROW1_Y, text_color)
+        display.text("B:{}".format(b), GRID_COL1_X, GRID_ROW2_Y, text_color)
+        display.text("C:{}".format(c), GRID_COL2_X, GRID_ROW2_Y, text_color)
+
+        display.show()
+        sleep_ms(100)  # Slower poll rate to avoid screen flickering and make text readable
+
+except KeyboardInterrupt:
+    print("\nColor lamp stopped.")
+finally:
+    # Clean up and power off display on exit
+    display.fill(0)
+    display.show()
+    sleep_ms(100)
+    display.power_off()