Adafruit_PWM_Servo_Driver on rev 2 Raspberry Pi

[micahflee]

I have a 16 channel servo driver (https://www.adafruit.com/products/815) that I connected to my Raspberry Pi rev 2, and now I'm trying to send data over I2C to make the motor work.

I'm trying to follow the instructions at http://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi/using-the-adafruit-library.

It says to clone this repo:

$ git clone https://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code.git
$ cd Adafruit-Raspberry-Pi-Python-Code
$ cd Adafruit_PWM_Servo_Driver

It also says to change the self.i2c = Adafruit_I2C(address) line, for the rev 2 Raspberry Pi:

If you have a second revision raspberry Pi, you'll need to update the default I2C port.  In the file Adafruit_PWM_Servo_Driver/Adafruit_PWM_Servo_Driver.py

change
self.i2c = Adafruit_I2C(address)
to
self.i2c = Adafruit_I2C(address, bus=smbus.SMBus(1))

You also need to add import smbus to the top of the file.

When I follow these instructions and then run "sudo python Servo_Example.py", I get this error:

[pi@raspberrypi] {master} ~/adafruit/Adafruit-Raspberry-Pi-Python-Code/Adafruit_PWM_Servo_Driver$ sudo python Servo_Example.py
Traceback (most recent call last):
  File "Servo_Example.py", line 12, in <module>
    pwm = PWM(0x40, debug=True)
  File "/home/pi/adafruit/Adafruit-Raspberry-Pi-Python-Code/Adafruit_PWM_Servo_Driver/Adafruit_PWM_Servo_Driver.py", line 31, in __init__
    self.i2c = Adafruit_I2C(address, bus=smbus.SMBus(1))
TypeError: __init__() got an unexpected keyword argument 'bus'

It looks like the Adafruit_I2C constructor doesn't let me pass in a bus? Do you know how I can get this working on my rev 2 RPi? Thanks!

[andrewbird]

Hi micahflee,
just reading the code in adafruit's Adafruit_I2C, it looks like you should pass an integer called busnum instead. By default it should do the right thing and select the correct bus based on RPi version, but you can force it by passing 'busnum=1'.

Hope it helps,

Andrew

[micahflee]

Thank you! I'll try this out soon and report back.

[micahflee]

Thanks, that worked.