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How to decipher i2cdetect matrix output?



  • I've been looking all over for good documentation for this, but I can't seem to decipher the output given by the console after running the following command:

    i2cdetect -y 0

    I've attached a picture of the console window output after I enter this command.

    0_1562450143298_IMG-3316.JPG



  • @Nathan-Guyette Please read this Linux man page
    i2cdetect(8) - Linux man page



  • Yes thank you, but that doesn't tell me what the rows and columns are, or how to decipher them.



  • @Nathan-Guyette Each I2C device must have a unique 7 bit address from 0x00 to 0x7f hex (ie. from 0 to 127 dec).
    0x00 - 0x02 (more exactly 0x00 - 0x07) and 0x78 - 0x7F are reserved I2C addresses.

    # Omega2+ FW v0.3.2 b223
    
    root@Omega-5BE1:/# i2cdetect -l
    i2c-0	i2c       	10000900.i2c                    	I2C adapter
    
    root@Omega-5BE1:/# i2cdetect -y 0
         0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
    00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
    10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
    20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
    30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
    40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
    50: -- -- -- -- -- -- -- 57 -- -- -- -- -- -- -- -- 
    60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- -- 
    70: -- -- -- -- -- -- -- --  
    
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x00 # seconds
    0x30
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x01 # minutes
    0x50
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x02 # hours
    0x21
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x03 # Day of the Week
    0x01
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x04 # Day
    0x08
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x05 # Month and Century
    0x07
    root@Omega-5BE1:/# i2cget -y 0 0x68 0x06 # Year
    0x19
    

    There are two (2) I2C devices on the i2c-0 bus of this Omega2:
    0x57 is a AT24C32 RAM
    0x68 is a DS3231 RTC
    and the current date and time is (2)019-07-08 Monday 21:50:30 UTC.

    Please search on the web 'DS3231 AT24C32 IIC High Precision Real Time Clock Module For Arduino'
    (on Omega2 the Vcc is 3.3 V)



  • Wow, thank you so much! This is exactly what I was looking for.


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