QMP6988 same address PaHub



  • hello everyone.
    I need some help. I'm trying to run multiple units through a PaHub but I'm experiencing problems with the ENV3 sensor, specifically the pressure.
    I realized that both the QMP6988 sensor and the PaHub use the same address, 0x70. Also, I read in the QMP6988 data sheet that it has two available addresses, the second of which is 0x56. I have tried every way to make QMP6988 communicate via address 0x56, but with no result always 0x70 uses. Can anyone help me please?
    I thank you in advance.
    Best regards Nicholas.



  • Hello @Nicholas-Parasporo

    I understand that to change the I2C address of the QMP6988 you need to modify the hardware. The SDO pin determines the I2C address. See schematic here. And documentation here. Section 4.5 I2C Protocol (page 18/27)

    • SDO low -> 0x70
    • SDO high -> 0x56

    Thanks
    Felix



  • @nicholas-parasporo
    Hi! The PaHub can support two devices of the same address. It is an I2C device splitter, which can expand a single Grove i2c interface to six channels, and allows you to mount slave devices with the same I2C address.
    More here!
    https://docs.m5stack.com/en/unit/pahub
    Cheers, Terry



  • Connect the QMP6 to the hub and the hub gives it a different virtual address.
    Address are often set at the hardware level and can sometimes be changes by changing the solder points on the PCB of the sensor.