Python wrapper for Atlas Scientific USB sensors

Installing dependencies.

• Install libftdi package.

    sudo apt-get install libftdi-dev 
  

• Install pylibftdi python package.

    sudo pip install pylibftdi
  

• Install dependencies

    sudo apt-get install sqlite
    sudo pip install xlwt
  

• Create SYMLINK of the FTDI adaptors.

  The following will allow ordinary users (e.g. ‘pi’ on the RPi) to access to the FTDI device without needing root permissions:

  If you are using device with root permission, just skip this step.

  Create udev rule file by typing sudo nano /etc/udev/rules.d/99-libftdi.rules and insert below:

    SUBSYSTEMS=="usb", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6015", GROUP="dialout", MODE="0660", SYMLINK+="FTDISerial_Converter_$attr{serial}"
  

  Press CTRL+X, Y and hit Enter to save & exit.

  Restart udev service to apply changes above.

    sudo service udev restart
  

• Modify FTDI python driver

  Since our FTDI devices use other USB PID(0x6015), we need to tweak the original FTDI Driver.

    sudo nano /usr/local/lib/python2.7/dist-packages/pylibftdi/driver.py
  

  Move down to the line 70 and add 0x6015 at the end of line.

  Original line:

    USB_PID_LIST = [0x6001, 0x6010, 0x6011, 0x6014]
  

  Added line:

    USB_PID_LIST = [0x6001, 0x6010, 0x6011, 0x6014, 0x6015]        
  

• Testing Installation.

  Connect your device, and run the following (as a regular user):

    python -m pylibftdi.examples.list_devices
  

  If all goes well, the program should report information about each connected device.

  If no information is printed, but it is when run with sudo,

  a possibility is permissions problems - see the section under Linux above regarding udev rules.

  You may get result like this:

    FTDI:FT230X Basic UART:DA00TN73
  

  FTDI adaptors has its own unique serial number.

  We need this to work with our sensors.

  In the result above, serial number is DA00TN73.

Install library

cd ~
git clone https://github.com/Atlas-Scientific/R-pi-database-.git
cd R-pi-database-
sudo python setup.py install

Test library

Here is the basic sample code.

import pylibAtlas      # import pylibAtlas library

db_test = 'test1.sqlite'
table_test = 'tb_test'

# Create database file and also table with given parameter.
# Note that the table has columns named id, time stamp, val1, val2, val3, val4 to store sensor data. 
pylibAtlas.create_table(db_test, table_test)    

# Once creating the database file and table, now let us read data from the sensor and save to db.
# Assume that sensor data has been saved to sensor_val variable.
pylibAtlas.insert_data(db_test, table_test, sensor_val)

# Now let us try to get last commited value
print "Last value:", pylibAtlas.get_last_value(db_test, table_test)

# Maximum value through the whole db
print "Max value: ", pylibAtlas.get_max_value(db_test, table_test)

# Minimum value through the whole db
print "Min value: ", pylibAtlas.get_min_value(db_test, table_test)

# When we forget table name, we can use this function to get table name from the db file.
print "Table name: ", pylibAtlas.get_table_name(db_test)

# export to excel file which has same file name with db file.
# test1.xlsx file will be created in the same directory.
print "Exporting: ", pylibAtlas.export_xls('test1.sqlite')