Fixed bug with bits 8-15, improved sample code

KTOWN · KTOWN · commit 3c5d3af876fa · 2013-08-20T13:11:09.000+02:00
diff --git a/Adafruit_MCP230xx/Adafruit_MCP230xx.py b/Adafruit_MCP230xx/Adafruit_MCP230xx.py
@@ -1,193 +1,170 @@
 #!/usr/bin/python
 
-# Copyright 2012 Daniel Berlin (with some changes by Limor Fried,
-# Adafruit Industries)
-
-# Permission is hereby granted, free of charge, to any person obtaining a
-# copy of this software and associated documentation files (the "Software"),
-# to deal in the Software without restriction, including without limitation
-# the rights to use, copy, modify, merge, publish, distribute, sublicense,
-# and/or sell copies of the Software, and to permit persons to whom the
-# Software is furnished to do so, subject to the following conditions:
-
-# The above copyright notice and this permission notice shall be included
-# in all copies or substantial portions of the Software.
+# Copyright 2012 Daniel Berlin (with some changes by Adafruit Industries/Limor Fried)
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy of
+# this software and associated documentation files (the "Software"), to deal  MCP230XX_GPIO(1, 0xin
+# the Software without restriction, including without limitation the rights to
+# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+# of the Software, and to permit persons to whom the Software is furnished to do
+# so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
 
 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
-# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-# DEALINGS IN THE SOFTWARE.
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
 
 from Adafruit_I2C import Adafruit_I2C
-
-class Adafruit_MCP230XX(Adafruit_I2C):
-
-    INPUT  = True
-    OUTPUT = False
-
-    MCP23017_IODIRA = 0x00
-    MCP23017_IODIRB = 0x01
-    MCP23017_GPPUA  = 0x0C
-    MCP23017_GPPUB  = 0x0D
-    MCP23017_GPIOA  = 0x12
-    MCP23017_GPIOB  = 0x13
-    MCP23017_OLATA  = 0x14
-    MCP23017_OLATB  = 0x15
-    MCP23008_IODIR  = 0x00
-    MCP23008_GPIO   = 0x09
-    MCP23008_GPPU   = 0x06
-    MCP23008_OLAT   = 0x0A
-
-
-    def __init__(self, address, num_gpios=8, busnum=-1, debug=False):
-
-        assert 0 < num_gpios < 17, "Number of GPIOs must be between 1 and 16"
-
-        self.i2c       = Adafruit_I2C(address, busnum, debug)
+import smbus
+import time
+
+MCP23017_IODIRA = 0x00
+MCP23017_IODIRB = 0x01
+MCP23017_GPIOA  = 0x12
+MCP23017_GPIOB  = 0x13
+MCP23017_GPPUA  = 0x0C
+MCP23017_GPPUB  = 0x0D
+MCP23017_OLATA  = 0x14
+MCP23017_OLATB  = 0x15
+MCP23008_GPIOA  = 0x09
+MCP23008_GPPUA  = 0x06
+MCP23008_OLATA  = 0x0A
+
+class Adafruit_MCP230XX(object):
+    OUTPUT = 0
+    INPUT = 1
+    
+    def __init__(self, address, num_gpios):
+        assert num_gpios >= 0 and num_gpios <= 16, "Number of GPIOs must be between 0 and 16"
+        self.i2c = Adafruit_I2C(address=address)
+        self.address = address
         self.num_gpios = num_gpios
-        self.pullups   = 0
 
-        # Set default pin values -- all inputs with pull-ups disabled.
-        # Current OLAT (output) value is polled, not set.
+        # set defaults
         if num_gpios <= 8:
-            self.direction = 0xFF
-            self.i2c.write8(self.MCP23008_IODIR, self.direction)
-            self.i2c.write8(self.MCP23008_GPPU , self.pullups)
-            self.outputvalue = self.i2c.readU8(self.MCP23008_OLAT)
-        else:
-            self.direction = 0xFFFF
-            self.i2c.write16(self.MCP23017_IODIRA, self.direction)
-            self.i2c.write16(self.MCP23017_GPPUA , self.pullups)
-            self.outputvalue = self.i2c.readU16(self.MCP23017_OLATA)
-
-
-    # Set single pin to either INPUT or OUTPUT mode
-    def config(self, pin, mode):
-
-        assert 0 <= pin < self.num_gpios, "Pin number %s is invalid, must be between 0 and %s" % (pin, self.num_gpios-1)
+            self.i2c.write8(MCP23017_IODIRA, 0xFF)  # all inputs on port A
+            self.direction = self.i2c.readU8(MCP23017_IODIRA)
+            self.i2c.write8(MCP23008_GPPUA, 0x00)
+        elif num_gpios > 8 and num_gpios <= 16:
+            self.i2c.write8(MCP23017_IODIRA, 0xFF)  # all inputs on port A
+            self.i2c.write8(MCP23017_IODIRB, 0xFF)  # all inputs on port B
+            self.direction = self.i2c.readU8(MCP23017_IODIRA)
+            self.direction |= self.i2c.readU8(MCP23017_IODIRB) << 8
+            self.i2c.write8(MCP23017_GPPUA, 0x00)
+            self.i2c.write8(MCP23017_GPPUB, 0x00)
+    
+    def _changebit(self, bitmap, bit, value):
+        assert value == 1 or value == 0, "Value is %s must be 1 or 0" % value
+        if value == 0:
+            return bitmap & ~(1 << bit)
+        elif value == 1:
+            return bitmap | (1 << bit)
+
+    def _readandchangepin(self, port, pin, value, currvalue = None):
+        assert pin >= 0 and pin < self.num_gpios, "Pin number %s is invalid, only 0-%s are valid" % (pin, self.num_gpios)
+        #assert self.direction & (1 << pin) == 0, "Pin %s not set to output" % pin
+        if not currvalue:
+             currvalue = self.i2c.readU8(port)
+        newvalue = self._changebit(currvalue, pin, value)
+        self.i2c.write8(port, newvalue)
+        return newvalue
 
-        if mode is self.INPUT: self.direction |=  (1 << pin)
-        else:                  self.direction &= ~(1 << pin)
 
+    def pullup(self, pin, value):
         if self.num_gpios <= 8:
-            self.i2c.write8(self.MCP23008_IODIR, self.direction)
-        elif pin < 8:
-            # Replace low bits (IODIRA)
-            self.i2c.write8(self.MCP23017_IODIRA, self.direction & 0xFF)
-        else:
-            # Replace high bits (IODIRB)
-            self.i2c.write8(self.MCP23017_IODIRB, self.direction >> 8)
-
-        return self.direction
-
-
-    # Enable pull-up resistor on single input pin
-    def pullup(self, pin, enable, check=False):
-
-        assert 0 <= pin < self.num_gpios, "Pin number %s is invalid, must be between 0 and %s" % (pin, self.num_gpios-1)
-        if check:
-            assert (self.direction & (1 << pin)) != 0, "Pin %s not set to input" % pin
-
-        if enable: self.pullups |=  (1 << pin)
-        else:      self.pullups &= ~(1 << pin)
+            return self._readandchangepin(MCP23008_GPPUA, pin, value)
+        if self.num_gpios <= 16:
+            if (pin < 8):
+                return self._readandchangepin(MCP23017_GPPUA, pin, value)
+            else:
+                return self._readandchangepin(MCP23017_GPPUB, pin-8, value) << 8
 
+    # Set pin to either input or output mode
+    def config(self, pin, mode):        
         if self.num_gpios <= 8:
-            self.i2c.write8(self.MCP23008_GPPU, self.pullups)
-        elif pin < 8:
-            # Replace low bits (GPPUA)
-            self.i2c.write8(self.MCP23017_GPPUA, self.pullups & 0xFF)
-        else:
-            # Replace high bits (GPPUB)
-            self.i2c.write8(self.MCP23017_GPPUB, self.pullups >> 8)
-
-        return self.pullups
-
-
-    # Read value from single input pin
-    def input(self, pin, check=True):
+            self.direction = self._readandchangepin(MCP23017_IODIRA, pin, mode)
+        if self.num_gpios <= 16:
+            if (pin < 8):
+                self.direction = self._readandchangepin(MCP23017_IODIRA, pin, mode)
+            else:
+                self.direction |= self._readandchangepin(MCP23017_IODIRB, pin-8, mode) << 8
 
-        assert 0 <= pin < self.num_gpios, "Pin number %s is invalid, must be between 0 and %s" % (pin, self.num_gpios-1)
-        if check:
-            assert (self.direction & (1 << pin)) != 0, "Pin %s not set to input" % pin
+        return self.direction
 
-        if self.num_gpios <= 8:
-            value = self.i2c.readU8(self.MCP23008_GPIO)
-            return (value >> pin) & 1
-        elif pin < 8:
-            # Read from low bits (GPIOA)
-            value = self.i2c.readU8(self.MCP23017_GPIOA)
-            return (value >> pin) & 1
-        else:
-            # Read from high bits (GPIOB)
-            value = self.i2c.readU8(self.MCP23017_GPIOB)
-            return (value >> (pin - 8)) & 1
-
-
-    # Write value to single output pin
     def output(self, pin, value):
-        assert 0 <= pin < self.num_gpios, "Pin number %s is invalid, must be between 0 and %s" % (pin, self.num_gpios-1)
         # assert self.direction & (1 << pin) == 0, "Pin %s not set to output" % pin
-
-        if value: new = self.outputvalue |  (1 << pin)
-        else:     new = self.outputvalue & ~(1 << pin)
-
-        # Only write if pin value has changed:
-        if new is not self.outputvalue:
-            self.outputvalue = new
-            if self.num_gpios <= 8:
-                self.i2c.write8(self.MCP23008_OLAT, new)
-            elif pin < 8:
-                # Write to low bits (OLATA)
-                self.i2c.write8(self.MCP23017_OLATA, new & 0xFF)
+        if self.num_gpios <= 8:
+            self.outputvalue = self._readandchangepin(MCP23008_GPIOA, pin, value, self.i2c.readU8(MCP23008_OLATA))
+        if self.num_gpios <= 16:
+            if (pin < 8):
+                self.outputvalue = self._readandchangepin(MCP23017_GPIOA, pin, value, self.i2c.readU8(MCP23017_OLATA))
             else:
-                # Write to high bits (OLATB)
-                self.i2c.write8(self.MCP23017_OLATB, new >> 8)
-
-        return new
-
+                self.outputvalue = self._readandchangepin(MCP23017_GPIOB, pin-8, value, self.i2c.readU8(MCP23017_OLATB)) << 8
 
-# The following two methods (inputAll and outputAll) neither assert
-# inputs nor invoke the base class methods that handle I/O exceptions.
-# The underlying smbus calls are invoked directly for expediency, the
-# expectation being that any I2C access or address type errors have
-# already been identified during initialization.
+        return self.outputvalue
 
-    # Read contiguous value from all input pins
-    def inputAll(self):
-      if self.num_gpios <= 8:
-        return self.i2c.bus.read_byte_data(self.i2c.address,
-         self.MCP23008_GPIO)
-      else:
-        return self.i2c.bus.read_word_data(self.i2c.address,
-         self.MCP23017_GPIOA)
-
-
-    # Write contiguous value to all output pins
-    def outputAll(self, value):
-      self.outputvalue = value
-      if self.num_gpios <= 8:
-        self.i2c.bus.write_byte_data(self.i2c.address,
-         self.MCP23008_OLAT, value)
-      else:
-        self.i2c.bus.write_word_data(self.i2c.address,
-         self.MCP23017_OLATA, value)
 
+        self.outputvalue = self._readandchangepin(MCP23017_IODIRA, pin, value, self.outputvalue)
+        return self.outputvalue
+        
+    def input(self, pin):
+        assert pin >= 0 and pin < self.num_gpios, "Pin number %s is invalid, only 0-%s are valid" % (pin, self.num_gpios)
+        assert self.direction & (1 << pin) != 0, "Pin %s not set to input" % pin
+        if self.num_gpios <= 8:
+            value = self.i2c.readU8(MCP23008_GPIOA)
+        elif self.num_gpios > 8 and self.num_gpios <= 16:
+            value = self.i2c.readU8(MCP23017_GPIOA)
+            value |= self.i2c.readU8(MCP23017_GPIOB) << 8
+        return value & (1 << pin)
+
+	def readU8(self):
+		result = self.i2c.readU8(MCP23008_OLATA)
+		return(result)
+
+	def readS8(self):
+		result = self.i2c.readU8(MCP23008_OLATA)
+		if (result > 127): result -= 256
+		return result
+
+	def readU16(self):
+		assert self.num_gpios >= 16, "16bits required"
+		lo = self.i2c.readU8(MCP23017_OLATA)
+		hi = self.i2c.readU8(MCP23017_OLATB)
+		return((hi << 8) | lo)
+
+	def readS16(self):
+		assert self.num_gpios >= 16, "16bits required"
+		lo = self.i2c.readU8(MCP23017_OLATA)
+		hi = self.i2c.readU8(MCP23017_OLATB)
+		if (hi > 127): hi -= 256
+		return((hi << 8) | lo)
+
+	def write8(self, value):
+		self.i2c.write8(MCP23008_OLATA, value)
+
+	def write16(self, value):
+		assert self.num_gpios >= 16, "16bits required"
+		self.i2c.write8(MCP23017_OLATA, value & 0xFF)
+		self.i2c.write8(MCP23017_OLATB, (value >> 8) & 0xFF)        
 
 # RPi.GPIO compatible interface for MCP23017 and MCP23008
 
 class MCP230XX_GPIO(object):
-    OUT   = 0
-    IN    = 1
-    BCM   = 0
+    OUT = 0
+    IN = 1
+    BCM = 0
     BOARD = 0
-
     def __init__(self, busnum, address, num_gpios):
         self.chip = Adafruit_MCP230XX(busnum, address, num_gpios)
     def setmode(self, mode):
-        pass # do nothing
+        # do nothing
+        pass
     def setup(self, pin, mode):
         self.chip.config(pin, mode)
     def input(self, pin):
@@ -196,28 +173,31 @@ def output(self, pin, value):
         self.chip.output(pin, value)
     def pullup(self, pin, value):
         self.chip.pullup(pin, value)
-
+        
 
 if __name__ == '__main__':
-
-    # ****************************************************
+    # ***************************************************
     # Set num_gpios to 8 for MCP23008 or 16 for MCP23017!
-    # If you have a new Pi you may also need to add: bus=1
-    # ****************************************************
-    mcp = Adafruit_MCP230XX(address=0x20, num_gpios=16)
-    
-    # Set pins 0, 1, 2 as outputs
+    # ***************************************************
+    mcp = Adafruit_MCP230XX(address = 0x20, num_gpios = 8) # MCP23008
+    # mcp = Adafruit_MCP230XX(address = 0x20, num_gpios = 16) # MCP23017
+	
+    # Set pins 0, 1 and 2 to output (you can set pins 0..15 this way)
     mcp.config(0, mcp.OUTPUT)
     mcp.config(1, mcp.OUTPUT)
     mcp.config(2, mcp.OUTPUT)
-    
+	
     # Set pin 3 to input with the pullup resistor enabled
-    mcp.pullup(3, True)
-
-    # Read pin 3 and display the results
-    print "%d: %x" % (3, mcp.input(3))
+    mcp.config(3, mcp.INPUT)
+    mcp.pullup(3, 1)
     
+    # Read input pin and display the results
+    print "Pin 3 = %d" % (mcp.input(3) >> 3)
+	
     # Python speed test on output 0 toggling at max speed
-    while True:
-      mcp.output(0, 1) # Pin 0 High
-      mcp.output(0, 0) # Pin 0 Low
+    print "Starting blinky on pin 0 (CTRL+C to quit)"
+    while (True):
+      mcp.output(0, 1)  # Pin 0 High
+      time.sleep(1);
+      mcp.output(0, 0)  # Pin 0 Low
+      time.sleep(1);
