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I2C No Device Found

DaveDaveDaveDave New Member Posts: 3

Good afternoon,

Well, I am having some problems with the procedure i2c. Actually I own a board UP Core with bios UP-CHCR1 R1.3(UCR1BM13)(01/18/2018), and I use a Ubuntu 18.04.3 LTS kernel 5.0.0-x and the chosen Bus is the 0 with pinout I2C0_SOCK_SDA 73 e I2C0_SOCK_SCL 75.

The aim is to connect an ADS1115(0x48) through the I2C.

Unfortunately, I am not having a positive result with that, even if I have connected everything because the converter has not being detected. All address are empty by running the tool "i2cdetect -y -r 0" . I checked other buses without any substantial result. After that I have checked the bus 0 status with the “i2cdetect -F 0" command and I got a “NO” answer with the "SMBus Quick Command" voice.

I have connected the same circuit to a microcontroller (ESP32) or RPI and everything works.

Looking forward your reply

Have a nice day

Kind regards

Comments

  • rogertsai(AAEON)rogertsai(AAEON) New Member Posts: 214 ✭✭✭
    edited March 6

    @DaveDave
    I2C0 (73, 75pin) is working normally for me. Please refer to the below for troubleshooting this case
    1. Have you installed UP kernel for Ubuntu 18.04? if not, please refer to the link below
    https://wiki.up-community.org/Ubuntu
    2. If you directly connect a I2C device to the I2C0 of EXHAT-100, you'll need to use a pull-up resistor to SCL& SDA before you connect with the device. Please note that the I2C bus I/O voltage is 1.8V.
    3. If you are using a 3.3V I2C device , you must use a level shifter from 1.8V to 3.3V

    i2cdetect -l //list all I2C bus

    i2cdetect -r -y 0 //scan devices on I2C bus 0, measure i2c with logic analyzer

  • DaveDaveDaveDave New Member Posts: 3

    Good afternoon,
    I have watched some community users working on the I2c1 so I welded again the pin-out on the I2C1.

    1. The Distro is 18.04.3 LTS + kernel patch 4.15 ppa:ubilinux/up (I have tested the ubilinux 4.0 too but no results).
    2. Our connection is managed from the EXHAT-100 pin to the I2C device, and the pull-up resistor are 4.7KOhm(2.2Vr_out).
    3. My I2C device works on 5V.

    Unfortunately I need to find a solution asap concerning this project, otherwise I will be obliged to change board and I would deeply regret it.

    Looking forward your reply
    Kind regards

  • rogertsai(AAEON)rogertsai(AAEON) New Member Posts: 214 ✭✭✭
    edited March 9

    @DaveDave
    Please make sure your I2C device (5V) can be controlled by 1.8v Host.
    If not, for your i2c device, i think you will need to shift the I2C's 1.8V signals to 5V (e.g. level shifter)

    For further details, kindly refer to the following document
    https://downloads.up-community.org/download/up-core-carrier-board-design-guide/

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