Merge pull request #129 from makermelissa/main

[hackapet/Adafruit_Blinka_Displayio.git] / displayio / _i2cdisplay.py

diff --git a/displayio/_i2cdisplay.py b/displayio/_i2cdisplay.py
index 67022f5c213048f4704d398d7a72f3429d270cf4..9611fb09187a687351c308a3cbb07097997b8eca 100644 (file)
--- a/displayio/_i2cdisplay.py
+++ b/displayio/_i2cdisplay.py
@@ -23,7 +23,7 @@ displayio for Blinka
 import time
 import busio
 import digitalio
-import circuitpython_typing
+from circuitpython_typing import ReadableBuffer
 from ._constants import CHIP_SELECT_UNTOUCHED, DISPLAY_COMMAND
 
 __version__ = "0.0.0+auto.0"
@@ -80,12 +80,7 @@ class I2CDisplay:
         time.sleep(0.0001)
         self._reset.value = True
 
-    def _begin_transaction(self) -> None:
-        """Lock the bus before sending data."""
-        while not self._i2c.try_lock():
-            pass
-
-    def send(self, command: int, data: circuitpython_typing.ReadableBuffer) -> None:
+    def send(self, command: int, data: ReadableBuffer) -> None:
         """
         Sends the given command value followed by the full set of data. Display state,
         such as vertical scroll, set via ``send`` may or may not be reset once the code is
@@ -99,7 +94,7 @@ class I2CDisplay:
         self,
         data_type: int,
         _chip_select: int,  # Chip select behavior
-        data: circuitpython_typing.ReadableBuffer,
+        data: ReadableBuffer,
     ):
         if data_type == DISPLAY_COMMAND:
             n = len(data)
@@ -109,12 +104,37 @@ class I2CDisplay:
                     command_bytes[2 * i] = 0x80
                     command_bytes[2 * i + 1] = data[i]
 
+            try:
                 self._i2c.writeto(self._dev_addr, buffer=command_bytes)
+            except OSError as error:
+                if error.errno == 121:
+                    raise RuntimeError(
+                        f"I2C write error to 0x{self._dev_addr:02x}"
+                    ) from error
+                raise error
         else:
             data_bytes = bytearray(len(data) + 1)
             data_bytes[0] = 0x40
             data_bytes[1:] = data
-            self._i2c.writeto(self._dev_addr, buffer=data_bytes)
+            try:
+                self._i2c.writeto(self._dev_addr, buffer=data_bytes)
+            except OSError as error:
+                if error.errno == 121:
+                    raise RuntimeError(
+                        f"I2C write error to 0x{self._dev_addr:02x}"
+                    ) from error
+                raise error
+
+    def _free(self) -> bool:
+        """Attempt to free the bus and return False if busy"""
+        if not self._i2c.try_lock():
+            return False
+        self._i2c.unlock()
+        return True
+
+    def _begin_transaction(self) -> bool:
+        """Lock the bus before sending data."""
+        return self._i2c.try_lock()
 
     def _end_transaction(self) -> None:
         """Release the bus after sending data."""