MCP23017 (and 23008 some day) classes

Author: ladyada

Adafruit_MCP230xx/Adafruit_MCP230xx.py

@@ -0,0 +1,182 @@
+#!/usr/bin/python
+
+# Copyright 2012 Daniel Berlin
+#
+# 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.
+
+from Adafruit_I2C import Adafruit_I2C
+import smbus
+import time
+
+
+MCP23008_IODIRA = 0x00
+
+MCP23017_IODIRA = 0x00
+MCP23017_IODIRB = 0x01
+MCP23017_GPIOA = 0x12
+MCP23017_GPIOB = 0x13
+MCP23017_GPPUA = 0x0C
+MCP23017_GPPUB = 0x0D
+MCP23017_OLATA = 0x14
+MCP23017_OLATB = 0x15
+
+OUTPUT = 0
+INPUT = 1
+    
+class Adafruit_MCP230XX(object):
+
+    def __init__(self, busnum, 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, smbus.SMBus(busnum), True)
+        self.address = address
+        self.num_gpios = num_gpios
+
+        # set defaults
+
+        if num_gpios <= 8:
+            self.i2c.write8(MCP23008_IODIRA, 0xFF)  # all inputs on port A
+            self.direction = self.i2c.readU8(MCP23008_IODIRA)
+            self.i2c.write8(MCP23008_GPPU, 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
+
+
+    def pullup(self, pin, value):
+        if self.num_gpios <= 8:
+            return self._readandchangepin(MCP23008_GPPU, 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)
+
+    # Set pin to either input or output mode
+    def config(self, pin, mode):        
+        if self.num_gpios <= 8:
+            self.direction = self._readandchangepin(MCP23008_IODIR, 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)
+
+        return self.direction
+
+    def output(self, pin, value):
+        assert self.direction & (1 << pin) == 0, "Pin %s not set to output" % pin
+
+        if self.num_gpios <= 8:
+            self.outputvalue = self._readandchangepin(MCP23008_GPIO, pin, value. self.i2c.readU8(MCP23008_OLAT))
+        if self.num_gpios <= 16:
+            if (pin < 8):
+                self.outputvalue = self._readandchangepin(MCP23017_GPIOA, pin, value, self.i2c.readU8(MCP23017_OLATA))
+            else:
+                self.outputvalue = self._readandchangepin(MCP23017_GPIOB, pin-8, value, self.i2c.readU8(MCP23017_OLATB))
+
+        return self.outputvalue
+
+
+        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_GPIO)
+        elif self.num_gpios > 8 and self.num_gpios <= 16:
+            value = self.i2c.readU16(MCP23017_GPIOA)
+            temp = value >> 8
+            value <<= 8
+            value |= temp
+        return value & (1 << pin)
+
+        
+
+# RPi.GPIO compatible interface for MCP23017 and MCP23008
+
+class MCP230XX_GPIO(object):
+    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):
+        # do nothing
+        pass
+    def setup(self, pin, mode):
+        self.chip.config(pin, mode)
+    def input(self, pin):
+        return self.chip.input(pin)
+    def output(self, pin, value):
+        self.chip.output(pin, value)
+    def pullup(self, pin, value):
+        self.chip.pullup(pin, value)
+        
+
+if __name__ == '__main__':
+
+    # input test
+#    for i in range(16):
+#        mcp.pullup(i, 1)
+#    while (True):
+#        for i in range(16):
+#           print "%d: %x" % (i, mcp.input(i) >> i)
+
+    # output test
+#    for i in range(16):
+#        mcp.config(i, OUTPUT)
+#    while (True):
+#        for i in range(16):
+#            mcp.output(i, 0)
+#        time.sleep(0.1)
+#        for i in range(16):
+#            mcp.output(i, 1)
+#        time.sleep(0.1)
+
+
+    mcp = Adafruit_MCP230XX(busnum = 1, address = 0x20, num_gpios = 16)
+    mcp.config(8, OUTPUT)
+    mcp.config(7, OUTPUT)
+    mcp.config(6, OUTPUT)
+    mcp.output(8, 1)
+    mcp.output(7, 1)
+    mcp.output(6, 1)