Added library for ALS PT19 Analog Light Sensor

Author: Sebastian Goscik

lib/ALSPT19/ALSPT19.py

@@ -0,0 +1,23 @@
+from machine import ADC
+import time
+
+class ALSPT19(object):
+    def __init__(self, pin_name):
+        adc = ADC()
+        self.pin = adc.channel(pin=pin_name, attn=ADC.ATTN_11DB, bits=12)
+        self.threshold = None
+
+    def calibrate(self, samples=300):
+        max_val = 0
+        for _ in range(samples):
+            val = self.pin()
+            if val > max_val:
+                max_val = val
+            time.sleep_ms(10)
+
+        self.threshold = max_val * 1.2
+
+    def is_on(self):
+        if self.pin() > self.threshold:
+            return True
+        return False