Attribute error: 'Adafruit_I2C' object has no attribute 'writeList'

Hi there,

I am using the motor bridge cape using BBB to run stepper motor. When I execute the test file,, I end up in the error “Attribute error: ‘Adafruit_I2C’ object has no attribute ‘writeList’”. Kindly help me in this issue.

Problem fixed. Thanks

1. install the adafruit_gpio

sudo apt-get update

sudo apt-get install build-essential python-pip python-dev python-smbus git

sudo pip install Adafruit-GPIO

2. install adafruit_bbio

sudo apt-get install build-essential python-dev python-pip -y

sudo pip install Adafruit_BBIO

3. change the as below

import Adafruit_GPIO.I2C as I2C

import Adafruit_BBIO.GPIO as GPIO

import time

Reset = “P9_23”

MotorBridge = I2C.Device(0x4b, 2)

GPIO.setup(Reset, GPIO.OUT)

4. Here is the output. I will update wiki soon.

debian@beaglebone:~/MotorBridgeCapeforBBG_BBB/tests$ python

Hello From MotorBridge

Hello From MotorBridge

Hello From MotorBridge


Seeed techsupport team


Hello Fellows and Ladies,

Is the new software, which is found on, for the Motor Bridge Cape ( used w/ only Python3 now?


This error happens because there is no attribute with the name you called, for that Object. This means that you got the error when the “module” does not contain the method you are calling. But it is evident that the method is there, which leads to believe that may be the method was added by you in the python source code after you had already imported the file (module). Or, some times packages get deprecated and they rename some functions. If that is true, then you may want to exit and reimport the module once again to be able to access the new method.

You can do it in another way to reimport the module with changes without having to exit the interpreter is to do the following:

import importlib


I started to use smbus2 which can be installed with pip3 after an apt install python3-pip installation.


# with help from @zmatt on Freenode

from smbus2 import SMBus
import time
import pathlib

# reset pin is P9.23, i.e. gpio1.17
reset_pin = pathlib.Path('/sys/class/gpio/gpio49/direction')

MotorBridge = SMBus('/dev/i2c-2')

ReadMode  = 0
WriteMode = 1
DeAddr    = 0X4B
ConfigValid = 0x3a6fb67c
DelayTime = 0.005

def WriteByte(Reg,Value):
data = [0 for i in range(2)]
data[0] = Reg
data[1] = Value
MotorBridge.write_i2c_block_data(0x4b, 1, data)

def WriteHalfWord(Reg,Value):
    data = [0 for i in range(3)]
    data[0] = Reg
    data[1] = Value & 0xff
    data[2] = (Value>>8) & 0xff
    MotorBridge.write_i2c_block_data(0x4b, 1, data)

def WriteOneWord(Reg,Value):
    data = [0 for i in range(5)]
    data[0] = Reg
    data[1] = Value & 0xff
    data[2] = (Value>>8) & 0xff
    data[3] = (Value>>16) & 0xff
    data[4] = (Value>>24) & 0xff
    MotorBridge.write_i2c_block_data(0x4b, 1, data)

def SetDefault():

On line 302 of the file, change the line to read:

filepath = "/dev/i2c-2".format(bus)

that should do it.

If you are making your source work in a virtual environment, sudo apt install python3-venv will take care of making some nice .txt files for use later in other Linux SBCs, e.g. requirements.txt is one.


P.S. If this makes sense, good. It took a while to get it to work without the read-only, deprecated versioning of Adafruit_GPIO.I2C as I2C.

Thank you for sharing. @silver1row


No issue, @Baozhu. It took me harassing a fellow quite a bit to figure it out. He figured it out before me b/c he knew how to read the file better than me. So, I kind of piggy-backed the source from him.