using I2C1 on the beaglebone black

Don Lawrence

Expert 1320 points

Hi. I am trying to get i2c1 up and running.

I noticed in the TRM for i2c0 the Control Module registers for SCL and SDA Pad Control:

988h conf_i2c0_sda
98Ch conf_i2c0_scl

However there are no pin addresses for i2c1.

In hw_control_AM335x.h the i2c0 pins are called:

CONTROL_CONF_I2C0_SDA & CONTROL_CONF_I2C0_SCL

However there is nothing for i2c1.

Are they named something else?

Does someone know where these DEFINES are?

thanks................dd

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Don,

The Sitara processor I/O pin naming convention follows this rule: Pin names, respectively padconf register names are taken from the Mode 0 functionality of the pin. I2C1 is not available in Mode 0 on any pins, therefore the missing names. On the BBB I2C1 is routed out from pins B16 (I2C1_SDA, pin name SPI0_D1) and A16 (I2C1_SCL, pin name SPI0_CS0). I2C1 is Mode 2 on both pins.

This information can be found in sections 4.2 - 4.3 in the AM335X Datasheet Rev. H and the BBB Schematics.

0 Don Lawrence over 10 years ago in reply to Biser Gatchev-XID

Expert 1320 points

OK Biser. That is it. But still incommunicado.

I must be doing something else wrong.

Thanks.................dd

0 Biser Gatchev-XID over 10 years ago in reply to Don Lawrence

TI__Guru**** 393215 points

Note that the I2C lines do not have external pullup resistors. You must provide these, connected to the BBB +3.3V power supply rail.

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using I2C1 on the beaglebone black