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ip_selctor [2014/12/30 17:42]
admin created 		ip_selctor [2014/12/30 22:09] (current)
admin
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 ---- ----
 **IP Selctor** **IP Selctor**
 +with the MCP23008 and MCP23017
 ---- ----
  
- +**Preparing the RPi for I2C:**\\
-**MCP23008 and MCP23017**\\+
 [[http://raspberrypi-aa.github.io/session3/i2c.html]]\\ [[http://raspberrypi-aa.github.io/session3/i2c.html]]\\
 +[[http://www.gsurf.de/vorbereiten-des-raspberry-pi-auf-i2c/]]\\
 +Open the file:\\
 +  $ sudo nano /etc/modprobe.d/raspi-blacklist.conf
 +Comment out:\\
 +  #blacklist i2c-bcm2708
 +Open the file:\\
 +  $ sudo nano /etc/modules
 +Add:\\
 +  i2c-dev
 +Load modules:\\
 +  $ sudo modprobe i2c_bcm2708
 +  $ sudo modprobe i2c-dev
 +Check the i2c modules:\\
 +  $ lsmod
 +  
 +  Module                  Size  Used by
 +  i2c_dev                 3792  0 
 +  i2c_bcm2708             3408  0 
 +Install some programs:\\
 +  $ sudo apt-get update
 +  $ sudo apt-get install i2c-tools
 +  $ sudo apt-get install python-smbus
 +Check the address:\\
 +  $ sudo i2cdetect -y 1
 +  $ sudo i2cdump -y 1 0x20
 +
 +**Library:**\\
 +[[https://learn.adafruit.com/mcp230xx-gpio-expander-on-the-raspberry-pi/overview]]\\
 +Download Adafruit libraries:\\
 +  $ wget https://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code/archive/master.zip
 +unpack:\\
 +  $ unzip master.zip
 +Example:\\
 +  # Set IP Address with MCP23008
 +  from Adafruit_MCP230xx import *
 +  # Use busnum = 0 for older Raspberry Pi's (256MB)
 +  # Use busnum = 1 for new Raspberry Pi's (512MB with mounting holes)
 +  mcp = Adafruit_MCP230XX(busnum = 1, address = 0x20, num_gpios = 8)
 +  # Set pins to input with the pullup resistor enabled
 +  for i in range(0,8):
 +    mcp.pullup(i, 1)
 +  # Read pins and display the results
 +  # bitshift output, third bit is the output
 +  meineIP=0
 +  for i in range(0,8):
 +    print "%d: %x" % (i, mcp.input(i) >> i)
 +    meineIP = meineIP +  mcp.input(i)
 +  print meineIP
 +
 +