I2C - Revision history

FabienM: /* On OPOS6UL */

2018-07-26T06:55:44Z

‎On OPOS6UL

FabienM: /* Read Write values */

2018-07-25T15:14:43Z

‎Read Write values

FabienM: /* On OPOS6UL */

2018-07-25T15:10:34Z

‎On OPOS6UL

FabienM: /* Read Write values */

2018-07-25T15:08:23Z

‎Read Write values

FabienM: /* On OPOS6UL */

2018-07-25T14:58:39Z

‎On OPOS6UL

FabienM: /* On OPOS6UL */

2018-07-25T14:51:57Z

‎On OPOS6UL

FabienM: /* On OPOS6UL */

2018-07-25T14:49:23Z

‎On OPOS6UL

FabienM: /* On APF27 */

2018-07-25T14:44:34Z

‎On APF27

FabienM: /* APF27 I2C chips */

2018-07-25T14:43:27Z

‎APF27 I2C chips

FabienM at 14:43, 25 July 2018

2018-07-25T14:43:10Z

@@ Line 34: / Line 34: @@
 </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 ===

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

@@ Line 28: / Line 28: @@
 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
 i2c-1	i2c       	21a4000.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]].
@@ Line 39: / Line 39: @@
 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
   1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
@@ Line 50: / Line 50: @@
 : 60 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
 : -- -- -- -- -- -- -- --
-</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
 x00, using read byte data.
@@ Line 63: / Line 63: @@
 * We can read the switch input with command :
-<source lang="bash">
+<pre class="apf">
 # i2cget -y 1 0x42 1
 x0e
 # i2cget -y 1 0x42 1
 x02
 * 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 0x55
 # i2cset -y 1 0x42 2 0xaa
-</source>
+</pre>
 == On APF27 ==

← Older revision		Revision as of 15:08, 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 ==

@@ Line 40: / Line 40: @@
 To see devices connected on one of the i2c master, use the command i2cdetect with the bus number:
 <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]
   1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
 :          -- -- -- -- -- -- -- -- -- -- -- -- --
@@ Line 55: / Line 51: @@
 : -- -- -- -- -- -- -- --
 </source>
-In this bus we can see 4 devices in addresses 0x40, 0x42, 0x43 and 0x60
+=== Read Write values ===
 == On APF27 ==

@@ Line 27: / Line 27: @@
 == 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.
 == On APF27 ==

← Older revision		Revision as of 14:44, 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 ==

@@ Line 34: / Line 34: @@
 * EEPROM:
-==APF27 I2C chips==
+===APF27 I2C chips===
 List of all hardware devices on APF27 I2C busses

@@ Line 48: / Line 48: @@
                    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
@@ Line 73: / Line 73: @@
                    * 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:
 * Connect pin 1 to the local GND