NSLU2-Linux
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Info.PinoutOfI2CPort History

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March 30, 2008, at 11:20 AM by bluepup -- Dead link removed
Deleted lines 15-16:

More information about the I²C bus can be found in the I²C FAQ. [dead link]

October 24, 2006, at 11:54 AM by TéJi -- dead link report
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More information about the I²C bus can be found in the I²C FAQ.

to:

More information about the I²C bus can be found in the I²C FAQ. [dead link]

January 07, 2006, at 04:22 PM by tman --
Changed lines 8-9 from:

An example that shows adding a connector for I²C expansion devices and includes test code that runs on OpenSlug is [[http://www.staton.us/electronics/open_slug/i2c_interface.html | NSLU2 I2C Interface].

to:

An example that shows adding a connector for I²C expansion devices and includes test code that runs on OpenSlug is Ken Staton's NSLU2 I²C Interface page.

January 07, 2006, at 02:01 PM by Staton --
Changed lines 8-9 from:

An example that shows adding a connector for I²C expansion devices and includes test code that runs on OpenSlug is [[http://www.staton.us/electronics/open_slug/i2c_interface.html | NSLU2 I2C? Interface].

to:

An example that shows adding a connector for I²C expansion devices and includes test code that runs on OpenSlug is [[http://www.staton.us/electronics/open_slug/i2c_interface.html | NSLU2 I2C Interface].

January 07, 2006, at 01:51 PM by Staton -- Openslug I2C code example
Added lines 8-9:

An example that shows adding a connector for I²C expansion devices and includes test code that runs on OpenSlug is [[http://www.staton.us/electronics/open_slug/i2c_interface.html | NSLU2 I2C? Interface].

September 17, 2005, at 03:01 PM by Phil Endecott --
Changed lines 6-7 from:

I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. There has been an unconfirmed report that the Xicor X1205 RTC chip has been replaced with a ST Microelectronics M41T11 RTC chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the RTC. The RTC is the small 8 pin SOIC near the 4 status LEDs.

to:

I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses its GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. There has been an unconfirmed report that the Xicor X1205 RTC chip has been replaced with a ST Microelectronics M41T11 RTC chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the RTC. The RTC is the small 8 pin SOIC near the 4 status LEDs.

Changed lines 10-11 from:

Note that although most of the NSLU2' components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is open-collector. The onboard I²C pull-ups (R144 & R145) to 3.3V bring the "high" level high enough for 5V devices to see it as a logical one (1). Note that the external devices should share their grounds for this to work.

to:

Note that although most of the NSLU2's components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is open-collector. The onboard I²C pull-ups (R144 & R145) to 3.3V bring the "high" level high enough for 5V devices to see it as a logical one (1). Note that the external devices should share their grounds for this to work.

August 22, 2005, at 02:55 PM by tman --
Changed lines 6-7 from:

I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. There has been an unconfirmed report that the Xicor X1205 RTC chip has been replaced with a ST Microelectronics M41T11? RTC chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the RTC. The RTC is the small 8 pin SOIC near the 4 status LEDs.

to:

I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. There has been an unconfirmed report that the Xicor X1205 RTC chip has been replaced with a ST Microelectronics M41T11 RTC chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the RTC. The RTC is the small 8 pin SOIC near the 4 status LEDs.

August 22, 2005, at 02:54 PM by tman --
Changed lines 6-7 from:

I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

to:

I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. There has been an unconfirmed report that the Xicor X1205 RTC chip has been replaced with a ST Microelectronics M41T11? RTC chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the RTC. The RTC is the small 8 pin SOIC near the 4 status LEDs.

June 09, 2005, at 12:40 AM by tman --
Changed lines 10-16 from:

Note that although most of the NSLU2' components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is open-collector. The onboard I2C? pull-ups (R144 & R145) to 3.3V bring the "high" level high enough for 5V devices to see it as a logical one (1). Note that the external devices should share their grounds for this to work.

Make sure that you do not connect the I²C bus pins to 5V as they are connected directly to the GPIO pins of the IXP420 and are not buffered. Anything higher than 3.3V will blow the driver in the IXP420 and there is no way to fix it. If you do manage to blow a pin then you will have to reuse one of the other GPIO pins like the disk LED lines. This will require soldering as you will need to remove the LED, SMD resistor for the LED and add a suitable I²C pull up.

More information about the I²C bus can be found in the I2C FAQ.

I2CChip.com has lots of good information on I²C (including pinouts of cables).

to:

Note that although most of the NSLU2' components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is open-collector. The onboard I²C pull-ups (R144 & R145) to 3.3V bring the "high" level high enough for 5V devices to see it as a logical one (1). Note that the external devices should share their grounds for this to work.

Make sure that you do not connect the I²C bus pins to 5V as they are connected directly to the GPIO pins of the IXP420 and are not buffered. Anything higher than 3.3V will blow the driver in the IXP420 and there is no way to fix it. If you do manage to blow a pin then you will have to reuse one of the other GPIO pins like the disk LED lines. This will require soldering as you will need to remove the LED, the SMD resistor for the LED and add a suitable I²C pull up.

More information about the I²C bus can be found in the I²C FAQ.

I2CChip.com has lots of good information on I²C (including pinouts of cables).

October 28, 2004, at 03:42 PM by tman --
Added lines 12-13:

Make sure that you do not connect the I²C bus pins to 5V as they are connected directly to the GPIO pins of the IXP420 and are not buffered. Anything higher than 3.3V will blow the driver in the IXP420 and there is no way to fix it. If you do manage to blow a pin then you will have to reuse one of the other GPIO pins like the disk LED lines. This will require soldering as you will need to remove the LED, SMD resistor for the LED and add a suitable I²C pull up.

October 20, 2004, at 09:46 PM by VoodooZ --
Changed line 10 from:

Note that although most of the NSLU2' components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is an open-collector bus. A pull-up to 3.3V is high enough for 5V devices to see the signal as a logical one (1). Note that the external devices should share their grounds for this to work.

to:

Note that although most of the NSLU2' components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is open-collector. The onboard I2C? pull-ups (R144 & R145) to 3.3V bring the "high" level high enough for 5V devices to see it as a logical one (1). Note that the external devices should share their grounds for this to work.

October 19, 2004, at 12:57 AM by tman --
Changed line 10 from:

Note that although most of the NSLU2' components run at 3.3V, the I2C? bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I2C? devices as the I2C? Bus is an open-collector bus. A pull-up to 3.3V is high enough for 5V devices to see the signal as a logical one (1). Note that the external devices should share their grounds for this to work.

to:

Note that although most of the NSLU2' components run at 3.3V, the I²C bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I²C devices as the I²C Bus is an open-collector bus. A pull-up to 3.3V is high enough for 5V devices to see the signal as a logical one (1). Note that the external devices should share their grounds for this to work.

Changed line 12 from:

More information about the I2C? bus can be found in the http://vhimpe.crosswinds.net/electronics/i2cfaq/i2c.html I2C FAQ.

to:

More information about the I²C bus can be found in the http://vhimpe.crosswinds.net/electronics/i2cfaq/i2c.html I2C FAQ.

Changed lines 14-16 from:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables).

--tman

to:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables).

October 14, 2004, at 02:46 PM by VoodooZ --
Changed lines 12-14 from:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables). More information about the I2C? bus can be found in the http://vhimpe.crosswinds.net/electronics/i2cfaq/i2c.html I2C FAQ.

to:

More information about the I2C? bus can be found in the http://vhimpe.crosswinds.net/electronics/i2cfaq/i2c.html I2C FAQ.

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables).

October 14, 2004, at 02:45 PM by VoodooZ --
Changed line 10 from:

Note that although most of the NSLU2' components run at 3.3V, the I2C? bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I2C? devices as I2C? devices use open-collector outputs. The 5V devices should interpret the "high" (3.3V) signal of the master appropriately. Note that the ground needs to me tied together for this to work.

to:

Note that although most of the NSLU2' components run at 3.3V, the I2C? bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I2C? devices as the I2C? Bus is an open-collector bus. A pull-up to 3.3V is high enough for 5V devices to see the signal as a logical one (1). Note that the external devices should share their grounds for this to work.

Changed line 12 from:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables).

to:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables). More information about the I2C? bus can be found in the http://vhimpe.crosswinds.net/electronics/i2cfaq/i2c.html I2C FAQ.

October 14, 2004, at 02:38 PM by VoodooZ --
Added lines 10-11:

Note that although most of the NSLU2' components run at 3.3V, the I2C? bus pins (SDA/SCL) from the RTC chip can be safely connected to external 5V I2C? devices as I2C? devices use open-collector outputs. The 5V devices should interpret the "high" (3.3V) signal of the master appropriately. Note that the ground needs to me tied together for this to work.

October 13, 2004, at 12:42 AM by rwhitby --
Changed line 10 from:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I2C? (including pinouts of cables).

to:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I²C (including pinouts of cables).

October 13, 2004, at 12:42 AM by rwhitby --
Added lines 10-11:

http://www.i2cchip.com/i2c_connector.html I2CChip.com has lots of good information on I2C? (including pinouts of cables).

October 10, 2004, at 12:26 AM by tman --
Changed lines 2-3 from:
SCLconnected to pin 6 of the X1205 RTC
SDAconnected to pin 5 of the X1205 RTC
to:
I2C SignalPCB Location
SCLConnected to pin 6 of the X1205 RTC
SDAConnected to pin 5 of the X1205 RTC
September 24, 2004, at 12:17 AM by tman --
Changed line 5 from:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a I²C interface (master) in software to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

to:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a 100KHz I²C master interface in software to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

Deleted line 7:
September 22, 2004, at 09:23 PM by tman --
Changed line 5 from:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU uses it's GPIO pins to emulate a I²C interface (master) in software to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

to:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP420 CPU uses it's GPIO pins to emulate a I²C interface (master) in software to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

September 20, 2004, at 07:32 PM by VoodooZ --
Changed line 5 from:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU uses it's GPIO pins to create a I²C interface to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

to:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU uses it's GPIO pins to emulate a I²C interface (master) in software to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

September 20, 2004, at 05:14 PM by ka6sox --
Added lines 8-10:

--tman

September 20, 2004, at 02:09 PM by tman --
Changed line 5 from:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU has a I²C controller built in which is used in the NSLU2 to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

to:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU uses it's GPIO pins to create a I²C interface to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

September 20, 2004, at 01:38 AM by ka6sox --
Changed line 5 from:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU has a I²C controller built in which is used in the NSLU2 to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs?.

to:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU has a I²C controller built in which is used in the NSLU2 to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs.

September 19, 2004, at 10:10 PM by tman --
Changed lines 5-7 from:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU has a I²C controller built in which is used in the NSLU2 to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. An example would be temperature sensors and ADCs?.

to:

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU has a I²C controller built in which is used in the NSLU2 to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. The X1205 is the small 8 pin SOIC near the 4 status LEDs?.

An example of possible addons would be http://www.semiconductors.philips.com/pip/LM75AD.html temperature sensors, http://www.semiconductors.philips.com/pip/PCF8574A.html IO ports and http://www.analog.com/en/prod/0,,AD7992,00.html ADCs.

September 19, 2004, at 10:00 PM by tman --
Changed lines 1-5 from:

Describe PinoutOfI2CPort here.

to:
SCLconnected to pin 6 of the X1205 RTC
SDAconnected to pin 5 of the X1205 RTC

http://www.semiconductors.philips.com/buses/i2c/ I2C is an inter IC communications bus which is widely used in embedded systems. The Intel IXP425 CPU has a I²C controller built in which is used in the NSLU2 to connect to the Xicor X1205 real time clock chip. Other chips may be added to the bus by tapping the SCL & SDA lines from the X1205. An example would be temperature sensors and ADCs?.

view · edit · print · history · Last edited by bluepup.
Based on work by TéJi, tman, Staton, Phil Endecott, VoodooZ, rwhitby, and ka6sox.
Originally by tman.
Page last modified on March 30, 2008, at 11:20 AM