From ed766a47ed81d5708220a2acf72e1670a7aa16e6 Mon Sep 17 00:00:00 2001
From: ladyada <limor@ladyada.net>
Date: Thu, 14 Feb 2019 16:58:22 -0500
Subject: [PATCH 1/3] bitmask is now within the byte defined for the bit

---
 adafruit_register/i2c_bit.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/adafruit_register/i2c_bit.py b/adafruit_register/i2c_bit.py
index 581be5d..9e59dad 100644
--- a/adafruit_register/i2c_bit.py
+++ b/adafruit_register/i2c_bit.py
@@ -43,10 +43,10 @@ class RWBit:
     :param int register_width: The number of bytes in the register. Defaults to 1.
     """
     def __init__(self, register_address, bit, register_width=1):
-        self.bit_mask = 1 << bit
+        self.bit_mask = 1 << (bit%8) # the bitmask *within* the byte!
         self.buffer = bytearray(1 + register_width)
         self.buffer[0] = register_address
-        self.byte = bit // 8 + 1
+        self.byte = bit // 8 + 1  # the byte number within the buffer
 
     def __get__(self, obj, objtype=None):
         with obj.i2c_device as i2c:
@@ -74,4 +74,4 @@ class ROBit(RWBit):
     :param int register_width: The number of bytes in the register. Defaults to 1.
     """
     def __set__(self, obj, value):
-        raise AttributeError()
+        raise AttributeError()
\ No newline at end of file

From 695205d1febe93106c6beedd3ebfd8b54d62c260 Mon Sep 17 00:00:00 2001
From: ladyada <limor@ladyada.net>
Date: Thu, 14 Feb 2019 17:10:51 -0500
Subject: [PATCH 2/3] handle multibyte (but not straddling' bits)

---
 adafruit_register/i2c_bits.py | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/adafruit_register/i2c_bits.py b/adafruit_register/i2c_bits.py
index 5afecd4..95cbe12 100644
--- a/adafruit_register/i2c_bits.py
+++ b/adafruit_register/i2c_bits.py
@@ -48,12 +48,13 @@ def __init__(self, num_bits, register_address, lowest_bit, register_width=1):
         self.bit_mask = 0
         for _ in range(num_bits):
             self.bit_mask = (self.bit_mask << 1) + 1
-        self.bit_mask = self.bit_mask << lowest_bit
-        if self.bit_mask >= (1 << 8):
-            raise ValueError()
+        self.bit_mask = self.bit_mask << (lowest_bit%8)
+        if self.bit_mask >= 0xFF:
+            raise ValueError("Cannot have more bits than fit in a single byte")
+
         self.buffer = bytearray(1 + register_width)
         self.buffer[0] = register_address
-        self.lowest_bit = lowest_bit
+        self.lowest_bit = lowest_bit % 8  # lowest bit within byte
         self.byte = lowest_bit // 8 + 1
 
     def __get__(self, obj, objtype=None):
@@ -69,6 +70,7 @@ def __set__(self, obj, value):
         with obj.i2c_device as i2c:
             i2c.write(self.buffer, end=1, stop=False)
             i2c.readinto(self.buffer, start=1)
+            
             # Set all of our bits to 1.
             self.buffer[self.byte] |= self.bit_mask
             # Set all 0 bits to 0 by anding together.
@@ -88,4 +90,4 @@ class ROBits(RWBits):
     :param int register_width: The number of bytes in the register. Defaults to 1.
     """
     def __set__(self, obj, value):
-        raise AttributeError()
+        raise AttributeError()
\ No newline at end of file

From 9a8090af9262b7856f7327c01bb67f88229f5682 Mon Sep 17 00:00:00 2001
From: ladyada <limor@ladyada.net>
Date: Thu, 14 Feb 2019 17:11:47 -0500
Subject: [PATCH 3/3] linted

---
 adafruit_register/i2c_bit.py  | 2 +-
 adafruit_register/i2c_bits.py | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/adafruit_register/i2c_bit.py b/adafruit_register/i2c_bit.py
index 9e59dad..92a327c 100644
--- a/adafruit_register/i2c_bit.py
+++ b/adafruit_register/i2c_bit.py
@@ -74,4 +74,4 @@ class ROBit(RWBit):
     :param int register_width: The number of bytes in the register. Defaults to 1.
     """
     def __set__(self, obj, value):
-        raise AttributeError()
\ No newline at end of file
+        raise AttributeError()
diff --git a/adafruit_register/i2c_bits.py b/adafruit_register/i2c_bits.py
index 95cbe12..e67ac0a 100644
--- a/adafruit_register/i2c_bits.py
+++ b/adafruit_register/i2c_bits.py
@@ -70,7 +70,6 @@ def __set__(self, obj, value):
         with obj.i2c_device as i2c:
             i2c.write(self.buffer, end=1, stop=False)
             i2c.readinto(self.buffer, start=1)
-            
             # Set all of our bits to 1.
             self.buffer[self.byte] |= self.bit_mask
             # Set all 0 bits to 0 by anding together.
@@ -90,4 +89,4 @@ class ROBits(RWBits):
     :param int register_width: The number of bytes in the register. Defaults to 1.
     """
     def __set__(self, obj, value):
-        raise AttributeError()
\ No newline at end of file
+        raise AttributeError()