Merge pull request #18 from fourstix/b_revert

Reverted write_then_readinto() to write() followed by read().

Author: fourstix

README.rst

@@ -160,6 +160,23 @@ Usage Example
    # cs.direction = digitalio.Direction.OUTPUT
    # as3935 = QwiicAS3935_SPI(spi, cs)
 
+Upgrading
+=========
+On supported GNU/Linux systems like the Raspberry Pi, you can upgrade the driver
+to the latest published version.
+
+To upgrade for current user:
+
+.. code-block:: shell
+
+    pip3 install --upgrade sparkfun-circuitpython-qwiicjoystick
+
+To upgrade system-wide (this may be required in some cases):
+
+.. code-block:: shell
+
+    sudo pip3 install --upgrade sparkfun-circuitpython-qwiicjoystick
+
 Contributing
 ============
 

sparkfun_qwiicas3935.py

@@ -598,8 +598,12 @@ def _read_register(self, register):
             # In the original commments, Phil Fenstermacher (pcfens) says this
             # trick is required because smbus doesn't support repeated I2C
             # starts to read the registers directly (singularly) on the sensor.
+            i2c.write(bytes([0x00]))
             result = bytearray(9)
-            i2c.write_then_readinto(bytes([0x00]), result)
+            # write_then_readinto() does not work reliably,
+            # so do explicit write followed by read into
+            # i2c.write_then_readinto(bytes([0x00]), result)
+            i2c.readinto(result)
             if self._debug:
                 print([hex(i) for i in result])
                 print("$%02X => %s" % (register, hex(result[register])))
@@ -621,8 +625,12 @@ def _read_byte(self, register):
             # In the original commments, Phil Fenstermacher (pcfens) says this
             # trick is required because smbus doesn't support repeated I2C
             # starts to read the registers directly (singularly) on the sensor.
+            i2c.write(bytes([0x00]))
             result = bytearray(0x3E)
-            i2c.write_then_readinto(bytes([0x00]), result)
+            # write_then_readinto() does not work reliably,
+            # so do explicit write followed by read into
+            # i2c.write_then_readinto(bytes([0x00]), result)
+            i2c.readinto(result)
             if self._debug:
                 print([hex(i) for i in result])
                 print("$%02X => %s" % (register, hex(result[register])))