diff --git a/adafruit_bno055.py b/adafruit_bno055.py
index 10fd1be..2ad5a28 100644
--- a/adafruit_bno055.py
+++ b/adafruit_bno055.py
@@ -392,7 +392,9 @@ def _write_register(self, register, data):  # pylint: disable=arguments-differ
         if not isinstance(data, bytes):
             data = bytes([data])
         self._uart.write(bytes([0xAA, 0x00, register, len(data)]) + data)
-        time.sleep(0.1)
+        now = time.monotonic()
+        while self._uart.in_waiting < 2 and time.monotonic() - now < 0.25:
+            pass
         resp = self._uart.read(self._uart.in_waiting)
         if len(resp) < 2:
             raise OSError("UART access error.")
@@ -400,9 +402,16 @@ def _write_register(self, register, data):  # pylint: disable=arguments-differ
             raise RuntimeError("UART write error: {}".format(resp[1]))
 
     def _read_register(self, register, length=1):  # pylint: disable=arguments-differ
-        self._uart.write(bytes([0xAA, 0x01, register, length]))
-        time.sleep(0.1)
-        resp = self._uart.read(self._uart.in_waiting)
+        i = 0
+        while i < 3:
+            self._uart.write(bytes([0xAA, 0x01, register, length]))
+            now = time.monotonic()
+            while self._uart.in_waiting < length + 2 and time.monotonic() - now < 0.1:
+                pass
+            resp = self._uart.read(self._uart.in_waiting)
+            if len(resp) >= 2 and resp[0] == 0xBB:
+                break
+            i += 1
         if len(resp) < 2:
             raise OSError("UART access error.")
         if resp[0] != 0xBB:
diff --git a/docs/conf.py b/docs/conf.py
index c5429f0..543cbaa 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -10,11 +10,7 @@
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = [
-    "sphinx.ext.autodoc",
-    "sphinx.ext.intersphinx",
-    "sphinx.ext.viewcode",
-]
+extensions = ["sphinx.ext.autodoc", "sphinx.ext.intersphinx", "sphinx.ext.viewcode"]
 
 # Uncomment the below if you use native CircuitPython modules such as
 # digitalio, micropython and busio. List the modules you use. Without it, the
@@ -144,7 +140,7 @@
         "Adafruit BNO055 Library Documentation",
         "Radomir Dopieralski",
         "manual",
-    ),
+    )
 ]
 
 # -- Options for manual page output ---------------------------------------
@@ -175,5 +171,5 @@
         "AdafruitBNO055Library",
         "One line description of project.",
         "Miscellaneous",
-    ),
+    )
 ]