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i2cdetect(8) [centos man page]

I2CDETECT(8)						      System Manager's Manual						      I2CDETECT(8)

NAME
i2cdetect - detect I2C chips SYNOPSIS
i2cdetect [-y] [-a] [-q|-r] i2cbus [first last] i2cdetect -F i2cbus i2cdetect -V i2cdetect -l DESCRIPTION
i2cdetect is a userspace program to scan an I2C bus for devices. It outputs a table with the list of detected devices on the specified bus. i2cbus indicates the number or name of the I2C bus to be scanned, and should correspond to one of the busses listed by i2cdetect -l. The optional parameters first and last restrict the scanning range (default: from 0x03 to 0x77). i2cdetect can also be used to query the functionalities of an I2C bus (see option -F.) WARNING
This program can confuse your I2C bus, cause data loss and worse! INTERPRETING THE OUTPUT
Each cell in the output table will contain one of the following symbols: o "--". The address was probed but no chip answered. o "UU". Probing was skipped, because this address is currently in use by a driver. This strongly suggests that there is a chip at this address. o An address number in hexadecimal, e.g. "2d" or "4e". A chip was found at this address. OPTIONS
-y Disable interactive mode. By default, i2cdetect will wait for a confirmation from the user before messing with the I2C bus. When this flag is used, it will perform the operation directly. This is mainly meant to be used in scripts. -a Force scanning of non-regular addresses. Not recommended. -q Use SMBus "quick write" commands for probing (by default, the command used is the one believed to be the safest for each address). Not recommended. This is known to corrupt the Atmel AT24RF08 EEPROM found on many IBM Thinkpad laptops. -r Use SMBus "read byte" commands for probing (by default, the command used is the one believed to be the safest for each address). Not recommended. This is known to lock SMBus on various write-only chips (most notably clock chips at address 0x69). -F Display the list of functionalities implemented by the adapter and exit. -V Display the version and exit. -l Output a list of installed busses. SEE ALSO
i2cdump(8), sensors-detect(8) AUTHOR
Frodo Looijaard, Mark D. Studebaker and Jean Delvare This manual page was originally written by Aurelien Jarno <aurel32@debian.org>, for the Debian GNU/Linux system. April 2008 I2CDETECT(8)

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I2CGET(8)						      System Manager's Manual							 I2CGET(8)

NAME
i2cget - read from I2C/SMBus chip registers SYNOPSIS
i2cget [-f] [-y] i2cbus chip-address [data-address [mode]] i2cget -V DESCRIPTION
i2cget is a small helper program to read registers visible through the I2C bus (or SMBus). OPTIONS
-V Display the version and exit. -f Force access to the device even if it is already busy. By default, i2cget will refuse to access a device which is already under the control of a kernel driver. Using this flag is dangerous, it can seriously confuse the kernel driver in question. It can also cause i2cget to return an invalid value. So use at your own risk and only if you know what you're doing. -y Disable interactive mode. By default, i2cget will wait for a confirmation from the user before messing with the I2C bus. When this flag is used, it will perform the operation directly. This is mainly meant to be used in scripts. Use with caution. There are two required options to i2cget. i2cbus indicates the number or name of the I2C bus to be scanned. This number should correspond to one of the busses listed by i2cdetect -l. chip-address specifies the address of the chip on that bus, and is an integer between 0x03 and 0x77. data-address specifies the address on that chip to read from, and is an integer between 0x00 and 0xFF. If omitted, the currently active register will be read (if that makes sense for the considered chip). The mode parameter, if specified, is one of the letters b, w or c, corresponding to a read byte data, a read word data or a write byte/read byte transaction, respectively. A p can also be appended to the mode parameter to enable PEC. If the mode parameter is omitted, i2cget defaults to a read byte data transaction, unless data-address is also omitted, in which case the default (and only valid) transaction is a single read byte. WARNING
i2cget can be extremely dangerous if used improperly. I2C and SMBus are designed in such a way that an SMBus read transaction can be seen as a write transaction by certain chips. This is particularly true if setting mode to cp (write byte/read byte with PEC). Be extremely careful using this program. SEE ALSO
i2cdump(8), i2cset(8) AUTHOR
Jean Delvare This manual page was strongly inspired from those written by David Z Maze for i2cset. May 2008 I2CGET(8)
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