I2c stops working when another I2C device is connected

@craver2000 wrote:

I am using Touch phat for my raspberry pi zero. I’ve no problems with it, and sudo i2cdetect -y 1 shows that the i2c is detected. However, when I connect two more I2C devices (Adafuit INA219) with I2C address 0x40 and 0x41, all I2c devices including Touch phat stops working. sudo i2cdetect -y 1 shows no I2C device detected. Running my Touch phat script gives me:

Traceback (most recent call last):
  File "script.py", line 11, in <module>
    import touchphat
  File "/usr/lib/python2.7/dist-packages/touchphat/__init__.py", line 13, in <module>
    dh = cap1xxx.Cap1166(i2c_addr=0x2c)
  File "/usr/lib/python2.7/dist-packages/cap1xxx.py", line 283, in __init__
    self.product_id = self._get_product_id()
  File "/usr/lib/python2.7/dist-packages/cap1xxx.py", line 469, in _get_product_id
    return self._read_byte(R_PRODUCT_ID)
  File "/usr/lib/python2.7/dist-packages/cap1xxx.py", line 494, in _read_byte
    return self.i2c.read_byte_data(self.i2c_addr, register)
IOError: [Errno 121] Remote I/O error

The error goes away when I disconnect the INA219 units from my I2C port. I appreciate any advice on why this error is occuring and how I can resolve it.

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