i2c scan and fake_mcp

diff --git a/src/busio.py b/src/busio.py
index 6912f0cc535c3ed5912d494beebf1a46f7467b25..cdce321172ce6f723ed6bfbb2a9e10027afe7599 100644 (file)
--- a/src/busio.py
+++ b/src/busio.py
@@ -9,6 +9,7 @@ See `CircuitPython:busio` in CircuitPython for more details.
 
 * Author(s): cefn
 """
+import os
 
 try:
     import threading
@@ -50,8 +51,10 @@ class I2C(Lockable):
             self._i2c = _I2C(frequency=frequency)
             return
         if detector.board.microchip_mcp2221:
-            from adafruit_blinka.microcontroller.mcp2221.i2c import I2C as _I2C
-
+            if "BLINKA_FORCEBOARD" not in os.environ:
+                from adafruit_blinka.microcontroller.mcp2221.i2c import I2C as _I2C
+            elif os.environ["BLINKA_FORCEBOARD"] == "MICROCHIP_MCP2221":
+                from adafruit_blinka.microcontroller.fake_mcp2221.i2c import I2C as _I2C
             self._i2c = _I2C(frequency=frequency)
             return
         if detector.board.greatfet_one: