Untested draft I2C

diff --git a/python/bitbangio/__init__.py b/python/bitbangio/__init__.py
new file mode 100644 (file)
index 0000000..3634f44
--- /dev/null
+++ b/python/bitbangio/__init__.py
@@ -0,0 +1,52 @@
+from machine import Pin, I2C as _I2C
+
+class I2C:
+    def __init__(self, scl, sda, frequency=400000):
+        self.init(scl, sda, frequency)
+
+    def init(self, scl, sda, frequency):
+        self.deinit()
+        id = -1 # force bitbanging implementation - in future introspect platform if SDA/SCL matches hardware I2C
+        self._i2c = _I2C(id, Pin(scl.id), Pin(sda.id), frequency)
+
+    def deinit(self):
+        try:
+            del self._i2c
+        except AttributeError:
+            pass
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        self.deinit()
+
+    def scan(self):
+        return self._i2c.scan()
+
+    def try_lock(self):
+        if self._locked:
+            return False
+        else:
+            self._locked=True
+            return True
+
+    def unlock(self):
+        if self._locked:
+            self._locked = False
+        else:
+            raise ValueError("Not locked")
+
+    def readfrom_into(self, address, buffer, start=0, end=None):
+        if start is not 0 or end is not None:
+            if end is None:
+                end = len(buffer)
+            buffer = memoryview(buffer)[start:end]
+        return self._i2c.readfrom_into(address, buffer, stop=False)
+
+    def writeto(self, address, buffer, start=0, end=None, stop=True):
+        if start is not 0 or end is not None:
+            if end is None:
+                end = len(buffer)
+            buffer = memoryview(buffer)[start:end]
+        return self._i2c.writeto(address, buffer, stop)