I2C - Revision history

FabienM: /* On OPOS6UL */

2018-07-26T06:55:44Z

On OPOS6UL

← Older revision		Revision as of 08:55, 26 July 2018
Line 34:		Line 34:
	</pre>		</pre>

	The second bus (I2C2) is available on the [[OPOS6ULDev#~~Tested_RPi_shields.2Fhats~~ \| RaspberryPi connector]].		The second bus (I2C2) is available on the [[OPOS6ULDev#Connectors \| RaspberryPi connector]].

	=== Detect ===		=== Detect ===

FabienM: /* Read Write values */

2018-07-25T15:14:43Z

Read Write values

@@ Line 75: / Line 75: @@
 # i2cset -y 1 0x42 2 0x55
 # i2cset -y 1 0x42 2 0xaa
 </pre>

FabienM: /* On OPOS6UL */

2018-07-25T15:10:34Z

On OPOS6UL

← Older revision		Revision as of 17:10, 25 July 2018
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	By default, OPOS6UL kernel and rootfs are compiled with [https://github.com/groeck/lm-sensors lm-sensors] tools. There are 2 i2c busses on the opos6ul numeroted 1 and 2 on schematics and 0,1 under Linux. The i2c busses can be listed with command i2cdetect:		By default, OPOS6UL kernel and rootfs are compiled with [https://github.com/groeck/lm-sensors lm-sensors] tools. There are 2 i2c busses on the opos6ul numeroted 1 and 2 on schematics and 0,1 under Linux. The i2c busses can be listed with command i2cdetect:
	<~~source lang~~="~~bash~~">		<pre class="apf">
	# i2cdetect -l		# i2cdetect -l
	i2c-1 i2c 21a4000.i2c I2C adapter		i2c-1 i2c 21a4000.i2c I2C adapter
	i2c-0 i2c 21a0000.i2c I2C adapter		i2c-0 i2c 21a0000.i2c I2C adapter
	</~~source~~>		</pre>

	The second bus (I2C2) is available on the [[OPOS6ULDev#Tested_RPi_shields.2Fhats \| RaspberryPi connector]].		The second bus (I2C2) is available on the [[OPOS6ULDev#Tested_RPi_shields.2Fhats \| RaspberryPi connector]].
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	To see devices connected on one of the i2c master, use the command i2cdetect with the bus number:		To see devices connected on one of the i2c master, use the command i2cdetect with the bus number:
	<~~source lang~~="~~bash~~">		<pre class="apf">
	# i2cdetect -y 1		# i2cdetect -y 1
	0 1 2 3 4 5 6 7 8 9 a b c d e f		0 1 2 3 4 5 6 7 8 9 a b c d e f
Line 50:		Line 50:
	60: 60 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --		60: 60 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	70: -- -- -- -- -- -- -- --		70: -- -- -- -- -- -- -- --
	</~~source~~>		</pre>
	{{Note\| On some x86 computer, the DDR timing is configured through a little i2c device, if wrong values are written in this component it can brick the computer. It's the reason why i2cdetect add a big warning when we try to detect device on a i2c bus :<pre> WARNING! This program can confuse your I2C bus, cause data loss and worse!		{{Note\| On some x86 computer, the DDR timing is configured through a little i2c device, if wrong values are written in this component it can brick the computer. It's the reason why i2cdetect add a big warning when we try to detect device on a i2c bus :<pre class="apf"> WARNING! This program can confuse your I2C bus, cause data loss and worse!
	I will read from device file /dev/i2c-1, chip address 0x3c, data address		I will read from device file /dev/i2c-1, chip address 0x3c, data address
	0x00, using read byte data.		0x00, using read byte data.
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	* We can read the switch input with command :		* We can read the switch input with command :
	<~~source lang~~="~~bash~~">		<pre class="apf">
	# i2cget -y 1 0x42 1		# i2cget -y 1 0x42 1
	0x0e		0x0e
	# i2cget -y 1 0x42 1		# i2cget -y 1 0x42 1
	0x02		0x02
			</pre>

	~~</source>~~
	* And we can write the leds output with command :		* And we can write the leds output with command :
	<~~source lang~~="~~bash~~">		<pre class="apf">
	# i2cset -y 1 0x42 2 0		# i2cset -y 1 0x42 2 0
	# i2cset -y 1 0x42 2 0x55		# i2cset -y 1 0x42 2 0x55
	# i2cset -y 1 0x42 2 0xaa		# i2cset -y 1 0x42 2 0xaa
	</~~source~~>		</pre>

	== On APF27 ==		== On APF27 ==

FabienM: /* Read Write values */

2018-07-25T15:08:23Z

Read Write values

← Older revision		Revision as of 17:08, 25 July 2018
Line 58:		Line 58:

	=== Read Write values ===		=== Read Write values ===

			Depending on the device plugged on the bus, it's possible to read/write registers with command i2cget and i2cwrite.
			For example, here we have a ioexpander like device plugged at address 0x42.

			* We can read the switch input with command :
			<source lang="bash">
			# i2cget -y 1 0x42 1
			0x0e
			# i2cget -y 1 0x42 1
			0x02

			</source>
			* And we can write the leds output with command :
			<source lang="bash">
			# i2cset -y 1 0x42 2 0
			# i2cset -y 1 0x42 2 0x55
			# i2cset -y 1 0x42 2 0xaa
			</source>

	== On APF27 ==		== On APF27 ==

FabienM: /* On OPOS6UL */

2018-07-25T14:58:39Z

On OPOS6UL

← Older revision		Revision as of 16:58, 25 July 2018
Line 40:		Line 40:
	To see devices connected on one of the i2c master, use the command i2cdetect with the bus number:		To see devices connected on one of the i2c master, use the command i2cdetect with the bus number:
	<source lang="bash">		<source lang="bash">
	# i2cdetect 1		# i2cdetect -y 1
	~~WARNING! This program can confuse your I2C bus, cause data loss and worse!~~
	~~I will probe file /dev/i2c~~-1.
	~~I will probe address range 0x03-0x77.~~
	~~Continue? [Y/n]~~
	0 1 2 3 4 5 6 7 8 9 a b c d e f		0 1 2 3 4 5 6 7 8 9 a b c d e f
	00: -- -- -- -- -- -- -- -- -- -- -- -- --		00: -- -- -- -- -- -- -- -- -- -- -- -- --
Line 55:		Line 51:
	70: -- -- -- -- -- -- -- --		70: -- -- -- -- -- -- -- --
	</source>		</source>
			{{Note\| On some x86 computer, the DDR timing is configured through a little i2c device, if wrong values are written in this component it can brick the computer. It's the reason why i2cdetect add a big warning when we try to detect device on a i2c bus :<pre> WARNING! This program can confuse your I2C bus, cause data loss and worse!
			I will read from device file /dev/i2c-1, chip address 0x3c, data address
			0x00, using read byte data.
			Continue? [Y/n] </pre> But it's not a problem on APF/OPOS and we can ignore this warnings with option '-y'}}
			In this bus we can see 4 devices in addresses 0x40, 0x42, 0x43 and 0x60.

	~~In this bus we can see 4 devices in addresses 0x40, 0x42, 0x43 and 0x60~~		=== Read Write values ===

	== On APF27 ==		== On APF27 ==

FabienM: /* On OPOS6UL */

2018-07-25T14:51:57Z

On OPOS6UL

@@ Line 27: / Line 27: @@
 == On OPOS6UL ==
-By default, OPOS6UL kernel and rootfs are compiled with [https://github.com/groeck/lm-sensors lm-sensors] tools. There are 2 i2c busses on the opos6ul numeroted 1 and 2 on schematics and 0,1 under Linux.
+By default, OPOS6UL kernel and rootfs are compiled with [https://github.com/groeck/lm-sensors lm-sensors] tools. There are 2 i2c busses on the opos6ul numeroted 1 and 2 on schematics and 0,1 under Linux. The i2c busses can be listed with command i2cdetect:
 The second bus (I2C2) is available on the [[OPOS6ULDev#Tested_RPi_shields.2Fhats | RaspberryPi connector]].
 === Detect ===
 == On APF27 ==

FabienM: /* On OPOS6UL */

2018-07-25T14:49:23Z

On OPOS6UL

← Older revision		Revision as of 16:49, 25 July 2018
Line 27:		Line 27:
	== On OPOS6UL ==		== On OPOS6UL ==

	By default, OPOS6UL kernel and rootfs are compiled with lm-sensors tools.		By default, OPOS6UL kernel and rootfs are compiled with [https://github.com/groeck/lm-sensors lm-sensors] tools. There are 2 i2c busses on the opos6ul numeroted 1 and 2 on schematics and 0,1 under Linux.

			The second bus (I2C2) is available on the [[OPOS6ULDev#Tested_RPi_shields.2Fhats \| RaspberryPi connector]].

			=== Detect ===

	== On APF27 ==		== On APF27 ==

FabienM: /* On APF27 */

2018-07-25T14:44:34Z

On APF27

← Older revision		Revision as of 16:44, 25 July 2018
Line 24:		Line 24:

	You can find a sample code under ''target/packages/ch7024ctrl/'' of the Armadeus distribution ( [http://armadeus.svn.sourceforge.net/viewvc/armadeus/trunk/target/packages/ch7024ctrl/ or here through SF's SVN browsing] )		You can find a sample code under ''target/packages/ch7024ctrl/'' of the Armadeus distribution ( [http://armadeus.svn.sourceforge.net/viewvc/armadeus/trunk/target/packages/ch7024ctrl/ or here through SF's SVN browsing] )

			== On OPOS6UL ==

			By default, OPOS6UL kernel and rootfs are compiled with lm-sensors tools.

	== On APF27 ==		== On APF27 ==

FabienM: /* APF27 I2C chips */

2018-07-25T14:43:27Z

APF27 I2C chips

← Older revision		Revision as of 16:43, 25 July 2018
Line 34:		Line 34:
	* EEPROM:		* EEPROM:

	==APF27 I2C chips==		===APF27 I2C chips===

	List of all hardware devices on APF27 I2C busses		List of all hardware devices on APF27 I2C busses

FabienM at 14:43, 25 July 2018

2018-07-25T14:43:10Z

← Older revision		Revision as of 16:43, 25 July 2018
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	I2C ADDRESS 0x50 to 0x57 (bits 0-2 are don't care)		I2C ADDRESS 0x50 to 0x57 (bits 0-2 are don't care)

	==APF27_DEV I2C chips==		===APF27_DEV I2C chips===

	List of all hardware devices on APF27_DEV I2C busses		List of all hardware devices on APF27_DEV I2C busses
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	* EDID memory area (256 bytes) 0x3F (default)		* EDID memory area (256 bytes) 0x3F (default)

	==I2C bus logic 5v level adaptation (if necessary)==		===I2C bus logic 5v level adaptation (if necessary)===
	if you want to use I2C devices which can not work with the I2C voltage of the APF board, a level translator has to be used, for example a PCA9306 from NXP:		if you want to use I2C devices which can not work with the I2C voltage of the APF board, a level translator has to be used, for example a PCA9306 from NXP:
	* Connect pin 1 to the local GND		* Connect pin 1 to the local GND