VAR-SOM-MX6 I2C: Difference between revisions
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= | = Reading / Writing from an I2C device= | ||
Variscite includes I2CTools as a part of the default file system build, examples of optional commands: <br> | Variscite includes I2CTools as a part of the default file system build, examples of optional commands: <br> | ||
i2cdump - dump the content of an I2C device <br> | i2cdump - dump the content of an I2C device <br> | ||
i2cset - write a single character to an I2C device<br> | i2cset - write a single character to an I2C device<br> | ||
i2cget - read a single character to an I2C device.<br> | i2cget - read a single character to an I2C device.<br> | ||
<br> | |||
In addition follow 'C' code example as describe in the linux kernel documentation : https://www.kernel.org/doc/Documentation/i2c/dev-interface | In addition follow 'C' code example as describe in the linux kernel documentation : https://www.kernel.org/doc/Documentation/i2c/dev-interface | ||
Revision as of 14:44, 10 December 2015
I2C buses
List I2C available devices:
root@var-som-mx6:~# ls -l /dev/i2c-* crw------- 1 root root 89, 0 Dec 6 10:31 /dev/i2c-0 crw------- 1 root root 89, 1 Dec 6 10:31 /dev/i2c-1 crw------- 1 root root 89, 2 Dec 6 10:31 /dev/i2c-2
System class:
root@var-som-mx6:~# ls /sys/class/i2c-dev/ i2c-0 i2c-1 i2c-2
I2C devices per bus
Scan bus 0:
root@var-som-mx6:~# i2cdetect -y -r 0
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- UU -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Scan bus 1:
root@var-som-mx6:~# i2cdetect -y -r 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- UU -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- UU -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- 37 -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- 49 -- -- -- -- -- --
50: UU -- -- -- -- -- 56 57 -- 59 -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Scan bus 2:
root@var-som-mx6:~# i2cdetect -y -r 2
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
Reading / Writing from an I2C device
Variscite includes I2CTools as a part of the default file system build, examples of optional commands:
i2cdump - dump the content of an I2C device
i2cset - write a single character to an I2C device
i2cget - read a single character to an I2C device.
In addition follow 'C' code example as describe in the linux kernel documentation : https://www.kernel.org/doc/Documentation/i2c/dev-interface
Avoid writing to any Variscite device.
Don't manipulate to any Variscite device you will damage the SOM!
When the device is marked with "UU" it says a driver is using it.
Driver with numbers are available.
Variscite devices:
I2C-0 0x3C CAMERA
I2C-1 0x37 HDMI
I2C-1 0x49 HDMI
I2C-1 0x59 HDMI
I2C-1 0x50
I2C-1 0x56 On-SOM EEPROM - do not alter
I2C-1 0x57 On-SOM EEPROM - do not alter
I2C-2 0x38 Capacitive touch panel
I2C-2 0x68 VAR-DVK-MX6 DS1307 RTC