Added I2C support

adafruit/Adafruit_I2C.py

@@ -0,0 +1,127 @@
+#!/usr/bin/python
+
+import smbus
+
+# ===========================================================================
+# Adafruit_I2C Base Class
+# ===========================================================================
+
+class Adafruit_I2C:
+
+  def getPiRevision():
+    "Gets the version number of the Raspberry Pi board"
+    # Courtesy quick2wire-python-api
+    # https://github.com/quick2wire/quick2wire-python-api
+    try:
+      with open('/proc/cpuinfo','r') as f:
+        for line in f:
+          if line.startswith('Revision'):
+            return 1 if line.rstrip()[-1] in ['1','2'] else 2
+    except:
+      return 0
+
+  def __init__(self, address, bus=smbus.SMBus(1 if getPiRevision() > 1 else 0), debug=False):
+    self.address = address
+    # By default, the correct I2C bus is auto-detected using /proc/cpuinfo
+    self.bus = bus
+    # 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.debug = debug
+
+  def reverseByteOrder(self, data):
+    "Reverses the byte order of an int (16-bit) or long (32-bit) value"
+    # Courtesy Vishal Sapre
+    dstr = hex(data)[2:].replace('L','')
+    byteCount = len(dstr[::2])
+    val = 0
+    for i, n in enumerate(range(byteCount)):
+      d = data & 0xFF
+      val |= (d << (8 * (byteCount - i - 1)))
+      data >>= 8
+    return val
+
+  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, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1
+
+  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, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1
+
+  def readList(self, reg, length):
+    "Read a list of bytes from the I2C device"
+    results = []
+    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, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1
+
+  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, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1
+
+  def readS8(self, reg):
+    "Reads a signed 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)
+      if (result > 127):
+        return result - 256
+      else:
+        return result
+    except IOError, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1
+
+  def readU16(self, reg):
+    "Reads an unsigned 16-bit value from the I2C device"
+    try:
+      hibyte = self.bus.read_byte_data(self.address, reg)
+      result = (hibyte << 8) + self.bus.read_byte_data(self.address, reg+1)
+      if (self.debug):
+        print "I2C: Device 0x%02X returned 0x%04X from reg 0x%02X" % (self.address, result & 0xFFFF, reg)
+      return result
+    except IOError, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1
+
+  def readS16(self, reg):
+    "Reads a signed 16-bit value from the I2C device"
+    try:
+      hibyte = self.bus.read_byte_data(self.address, reg)
+      if (hibyte > 127):
+        hibyte -= 256
+      result = (hibyte << 8) + self.bus.read_byte_data(self.address, reg+1)
+      if (self.debug):
+        print "I2C: Device 0x%02X returned 0x%04X from reg 0x%02X" % (self.address, result & 0xFFFF, reg)
+      return result
+    except IOError, err:
+      print "Error accessing 0x%02X: Check your I2C address" % self.address
+      return -1

test/test_i2c.py

@@ -0,0 +1,26 @@
+import gaugette.ssd1306 as ssd1306
+import fonts.arial_regular_10
+
+ssd1306 = ssd1306.SSD1306_I2C(buffer_rows=32, buffer_cols=128)
+
+#ssd1306.draw_line(0,0,ssd1306.cols,ssd1306.rows,1)
+#ssd1306.draw_circle(16,18,12,1)
+
+ssd1306.draw_fast_vline(64, 0, 15)
+
+# border-line cases
+y=3
+dh=0
+for i in range(0,8):
+    ssd1306.draw_fast_vline(i, y+0, i+1+dh)
+    ssd1306.draw_fast_vline(8+i, y+i, 8-i+dh)
+    ssd1306.draw_fast_vline(16+i, i, 1)
+    ssd1306.draw_fast_vline(24+i, i, 2)
+    ssd1306.draw_fast_vline(32+i, i, 3)
+    ssd1306.draw_fast_vline(48+i, i, 15-2*i)
+    pass
+
+
+#ssd1306.draw_fast_vline(1, 1, ssd1306.buffer_rows-2)
+#ssd1306.draw_fast_vline(0, 0, ssd1306.buffer_rows)
+#ssd1306.fill_rect(110, 8, 3, 3, 1)