wasp: cst816s: Initial PoC driver

wasp/drivers/cst816s.py

@@ -0,0 +1,30 @@
+"""Hynitron CST816S touch contoller driver for MicroPython."""
+
+import watch
+
+class CST816S:
+    """Hynitron CST816S I2C touch controller driver."""
+    
+    def __init__(self):
+        self.dbuf = bytearray(6)
+        pass
+
+    def get_event(self, queue):
+        """Receive a touch event.
+
+        Check for a pending touch event and, if an event is pending,
+        prepare it ready to go in the event queue.
+
+        :return: True if an event is received, False otherwise.
+        """
+        dbuf = self.dbuf
+
+        try:
+            watch.i2c.readfrom_mem_into(21, 1, dbuf)
+        except OSError:
+            return False
+
+        queue[0] = dbuf[0]
+        queue[1] = ((dbuf[2] & 0xf) << 8) + dbuf[3]
+        queue[2] = ((dbuf[4] & 0xf) << 8) + dbuf[5]
+        return True