Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A13 => Topic started by: dhlii on November 10, 2013, 12:44:41 AM

Title: UEXT I2C
Post by: dhlii on November 10, 2013, 12:44:41 AM
I am trying to connect a PCF8574 Via I2c/UEXT-1

I have breadboarded a circuit and can access it using I@C from my laptop.
When I move the power/gnd/sda/scl lines to the A13 UEXT-1 connector and try the same things their
i2cdetect never sees the device and taxes forever to run.

i have the following in my script.fex.

[twi2_para]
twi2_used = 1
twi2_scl = port:PB17<2><default><default><default>
twi2_sda = port:PB18<2><default><default><default>

I can detect devices on i2c-0 and i2c-1

Nothing else in the fex is on PB17 and PB18.

Any clues ?


Title: Re: UEXT I2C
Post by: dhlii on November 11, 2013, 05:16:54 PM
Further information:

Everything works if I use twi0 or twi1 on GPIO2.

So the problem is either pin muxing for UEXT-1 or dead pins.
Title: Re: UEXT I2C
Post by: dhlii on December 08, 2013, 06:09:18 AM
Aparently my A13 has some dead UEXT pins.
I bought another A13 and things worked.