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:
- •
- "--". The address was probed but no chip
answered.
- •
- "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.
- •
- 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.