feat(vl53l1x): Add radar screen example with OLED.

lib/vl53l1x/examples/radar_screen.py

@@ -0,0 +1,78 @@
+"""Radar screen example using VL53L1X and SSD1327 OLED.
+
+Displays a real-time distance bar on the screen. The closer the object,
+the longer and brighter the bar, similar to a car parking sensor.
+Adapted for a round display bezel.
+"""
+
+from time import sleep_ms
+
+import ssd1327
+from machine import I2C, SPI, Pin
+from vl53l1x import VL53L1X
+
+MAX_DISTANCE_MM = 1000
+
+# Layout constants for the round screen
+BAR_X = 24
+BAR_Y = 70
+BAR_MAX_WIDTH = 80
+BAR_HEIGHT = 15
+TEXT_LBL_X = 28
+TEXT_LBL_Y = 35
+TEXT_VAL_X = 36
+TEXT_VAL_Y = 50
+TEXT_OUT_X = 16  # Shifted left to fit the longer "Out of range" text
+
+i2c = I2C(1)
+tof = VL53L1X(i2c)
+
+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)
+
+try:
+    while True:
+        distance = tof.read()
+
+        # Clear the display frame buffer
+        display.fill(0)
+
+        # Clamp distance to maximum range and compute integer proximity
+        clamped_dist = max(0, min(distance, MAX_DISTANCE_MM))
+        proximity = MAX_DISTANCE_MM - clamped_dist
+
+        # Map proximity to bar width (max 80px) and brightness (max 15)
+        bar_width = (80 * proximity) // MAX_DISTANCE_MM
+        brightness = (15 * proximity) // MAX_DISTANCE_MM
+
+        # If the object is within the detection range, ensure minimum visibility
+        if distance <= MAX_DISTANCE_MM:
+            bar_width = max(1, bar_width)
+            brightness = max(1, brightness)
+
+        # Draw the outline box (1 pixel larger than the max bar size) at max brightness
+        display.framebuf.rect(BAR_X - 1, BAR_Y - 1, BAR_MAX_WIDTH + 2, BAR_HEIGHT + 2, 15)
+        # Draw the distance bar centered: x=24, y=70, max_width=80, height=15
+        display.framebuf.fill_rect(BAR_X, BAR_Y, bar_width, BAR_HEIGHT, brightness)
+
+        # Display distance or "Out of range"
+        if distance > MAX_DISTANCE_MM:
+            display.text("Out of range", TEXT_OUT_X, TEXT_VAL_Y, 15)
+        else:
+            display.text("{} mm".format(distance), TEXT_VAL_X, TEXT_VAL_Y, 15)
+
+        # Send the buffer to the physical screen
+        display.show()
+
+        sleep_ms(50)
+
+except KeyboardInterrupt:
+    pass
+finally:
+    # Clear the screen on exit or error
+    display.fill(0)
+    display.show()