title: Grove Pi+ Multichannel Gas Sensor Raspberry Pi
body: <p>I am using a Raspberry Pi 3 B model with a Grove Pi+ (1.2.2 firmware), and Raspbian for Robots Image.
  I am plug-in the Multichannel Gas Sensor in I2C-1 port, and I am trying to execute the code that is <a href="https://github.com/DexterInd/GrovePi/blob/master/Software/Python/grove_i2c_multichannel_gas_sensor/multichannel_gas_sensor.py" rel="nofollow">available in Dexter´s Github</a>. I am getting the following issues:</p>
  
  <pre><code>&gt;     Traceback (most recent call last): File "/home/pi/Desktop/GrovePi/Software/Python/grove_i2c_multichannel_gas_sensor/multichannel_gas_sensor.py",
  &gt; line 85, in m= MutichannelGasSensor() File
  &gt; "/home/pi/Desktop/GrovePi/Software/Python/grove_i2c_multichannel_gas_sensor/multichannel_gas_sensor.py",
  &gt; line 39, in init if self.readR0() &gt;= 0: File
  &gt; "/home/pi/Desktop/GrovePi/Software/Python/grove_i2c_multichannel_gas_sensor/multichannel_gas_sensor.py",
  &gt; line 45, in readR0 rtnData = self.readData(0x11) File
  &gt; "/home/pi/Desktop/GrovePi/Software/Python/grove_i2c_multichannel_gas_sensor/multichannel_gas_sensor.py",
  &gt; line 70, in readData buffer=bus.read_i2c_block_data(self.address, cmd,
  &gt; 4)IOError: [Errno 110] Connection timed out
  </code></pre>
  
  <p>When I was running the old firmware of GrovePi+, this error was not appearing, but it was not working, nothing appears on screen.</p>
  
  <p>Checking the code line by line, I realize that in line 71 is print(data), after the buffer=bus.read_i2c_block_data(self.address, cmd, 4), but "data" variable is not defined in the code. Something is strange in this code.</p>
  
  <p>Can someone help me with this grove pi sensor? Can someone give me any hint?</p>