reformat

Author: dhhagan

ADS1115/ADS1115.py

@@ -1,6 +1,5 @@
 import time
 import smbus
-from I2C import Adafruit_I2C
 
 __all__ = ['ADS1115']
 
@@ -175,3 +174,150 @@ def readADCSingleEnded(self, channel=0, pga=6144, sps=250):
             return (val - 0xFFFF)*pga/32768.0
         else:
             return ( (result[0] << 8) | (result[1]) )*pga/32768.0
+
+
+# ===========================================================================
+# Adafruit_I2C Class
+# ===========================================================================
+
+class Adafruit_I2C(object):
+
+    @staticmethod
+    def getPiRevision():
+        "Gets the version number of the Raspberry Pi board"
+        # Revision list available at: http://elinux.org/RPi_HardwareHistory#Board_Revision_History
+        try:
+            with open('/proc/cpuinfo', 'r') as infile:
+                for line in infile:
+                    # Match a line of the form "Revision : 0002" while ignoring extra
+                    # info in front of the revsion (like 1000 when the Pi was over-volted).
+                    match = re.match('Revision\s+:\s+.*(\w{4})$', line)
+                    if match and match.group(1) in ['0000', '0002', '0003']:
+                        # Return revision 1 if revision ends with 0000, 0002 or 0003.
+                        return 1
+                    elif match:
+                        # Assume revision 2 if revision ends with any other 4 chars.
+                        return 2
+                    # Couldn't find the revision, assume revision 0 like older code for compatibility.
+            return 0
+        except:
+            return 0
+
+    @staticmethod
+    def getPiI2CBusNumber():
+        # Gets the I2C bus number /dev/i2c#
+        return 1 if Adafruit_I2C.getPiRevision() > 1 else 0
+
+    def __init__(self, address, busnum=-1, debug=False):
+        self.address = address
+        # By default, the correct I2C bus is auto-detected using /proc/cpuinfo
+        # Alternatively, you can hard-code the bus version below:
+        # self.bus = smbus.SMBus(0); # Force I2C0 (early 256MB Pi's)
+        # self.bus = smbus.SMBus(1); # Force I2C1 (512MB Pi's)
+        self.bus = smbus.SMBus(busnum if busnum >= 0 else Adafruit_I2C.getPiI2CBusNumber())
+        self.debug = debug
+
+    def reverseByteOrder(self, data):
+        ''' Reverses the byte order of an int (16-bit) or long (32-bit) value '''
+        byteCount = len(hex(data)[2:].replace('L','')[::2])
+        val       = 0
+        for i in range(byteCount):
+            val    = (val << 8) | (data & 0xff)
+            data >>= 8
+        return val
+
+    def errMsg(self):
+        print ("Error accessing 0x%02X: Check your I2C address" % self.address)
+        return -1
+
+    def write8(self, reg, value):
+        "Writes an 8-bit value to the specified register/address"
+        try:
+            self.bus.write_byte_data(self.address, reg, value)
+            if self.debug:
+                print ("I2C: Wrote 0x%02X to register 0x%02X" % (value, reg))
+        except IOError:
+            return self.errMsg()
+
+    def write16(self, reg, value):
+        "Writes a 16-bit value to the specified register/address pair"
+        try:
+            self.bus.write_word_data(self.address, reg, value)
+            if self.debug:
+                print ("I2C: Wrote 0x%02X to register pair 0x%02X,0x%02X" % (value, reg, reg+1))
+        except IOError:
+            return self.errMsg()
+
+    def writeRaw8(self, value):
+        "Writes an 8-bit value on the bus"
+        try:
+            self.bus.write_byte(self.address, value)
+            if self.debug:
+                print ("I2C: Wrote 0x%02X" % value)
+        except IOError:
+            return self.errMsg()
+
+    def writeList(self, reg, list):
+        "Writes an array of bytes using I2C format"
+        try:
+            if self.debug:
+                print ("I2C: Writing list to register 0x%02X:" % reg)
+                print (list)
+            self.bus.write_i2c_block_data(self.address, reg, list)
+        except IOError:
+            return self.errMsg()
+
+    def readList(self, reg, length):
+        "Read a list of bytes from the I2C device"
+        try:
+            results = self.bus.read_i2c_block_data(self.address, reg, length)
+            if self.debug:
+                print ("I2C: Device 0x%02X returned the following from reg 0x%02X" % (self.address, reg))
+                print (results)
+            return results
+        except IOError:
+            return self.errMsg()
+
+    def readU8(self, reg):
+        "Read an unsigned byte from the I2C device"
+        try:
+            result = self.bus.read_byte_data(self.address, reg)
+            if self.debug:
+                print ("I2C: Device 0x%02X returned 0x%02X from reg 0x%02X" % (self.address, result & 0xFF, reg))
+            return (result)
+        except IOError:
+            return self.errMsg()
+
+    def readS8(self, reg):
+        "Reads a signed byte from the I2C device"
+        try:
+            result = self.bus.read_byte_data(self.address, reg)
+            if result > 127: result -= 256
+            if self.debug:
+                print ("I2C: Device 0x%02X returned 0x%02X from reg 0x%02X" % (self.address, result & 0xFF, reg))
+            return result
+        except IOError:
+            return self.errMsg()
+
+    def readU16(self, reg, little_endian=True):
+        "Reads an unsigned 16-bit value from the I2C device"
+        try:
+            result = self.bus.read_word_data(self.address,reg)
+            # Swap bytes if using big endian because read_word_data assumes little 
+            # endian on ARM (little endian) systems.
+            if not little_endian:
+                result = ((result << 8) & 0xFF00) + (result >> 8)
+            if (self.debug):
+                print ("I2C: Device 0x%02X returned 0x%04X from reg 0x%02X" % (self.address, result & 0xFFFF, reg))
+            return result
+        except IOError:
+            return self.errMsg()
+
+    def readS16(self, reg, little_endian=True):
+        "Reads a signed 16-bit value from the I2C device"
+        try:
+            result = self.readU16(reg,little_endian)
+            if result > 32767: result -= 65536
+            return result
+        except IOError:
+            return self.errMsg()

ADS1115/I2C.py

@@ -11,7 +11,7 @@
 	from distutils.core import setup
 
 setup(name='ADS1115',
-      version='0.1.0',
+      version='0.1.1',
       description='Python library for interacting with the ADS1115 Analog to Digital Converter.',
       url='http://github.com/dhhagan/Adafruit-Raspberry-Pi-Python-Code',
       author='David H Hagan',