COMMUNICATION_ERROR I2C address 0x08

[dpezto]

I just received a 2nd hand PiJuice HAT and I'm having trouble setting it up. When running the CLI the HAT status shows Fault: COMMUNICATION_ERROR.
I ran the i2cdetect -y 1 and got:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         08 -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- -- 

I tried the PiJuice bricked after unsuccessful firmware update using address 0x08 and got the firmware successfully flashed but still pijuice_cli shows the communication error.

What am I missing here?

[tvoverbeek]

Is the i2cdetect -y 1 output after a reboot still the same?

[dpezto]

Yes, it's still the same.

[tvoverbeek]

It seems the previous owner changed the I2C address from the default 14 to 8.
pijuice_cli by default uses address 0x14, since it does not know the address has changed.
It can be changed in the CLI or GUI and the non-standard address is stored in the pijuice settings file /var/lib/pijuice/pijuice_config.JSON.
Edit the settings file /var/lib/pijuice/pijuice_config.JSON by adding the following lines before the closing brace:

  "board": {
    "general": {
      "i2c_addr": "8"
    }
  }

Note 1: Each line starts with 2 spaces
Note 2: You have to be root in order to edit the file.

Try this and see if you can run pijuice_cli without communication error.
In the General tab you can then reset the I2C adddress to its default.

[dpezto]

That was it, thank you!