Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => iMX233 => Topic started by: tselmeci on October 22, 2013, 12:41:17 pm

Title: GPIO pullups
Post by: tselmeci on October 22, 2013, 12:41:17 pm
Hello all!

I've been doing some development on imx233-olinuxino. I need to use many of the GPIO lines, mostly for output, but I'd also need 5-7 input lines.

As I have observed, certain pins don't have a pullup configuration. I made a try to enable the pullup configuration in the kernel (2.6.35.3) in imx233_olinuxino_pins.c, without effect, so if it's configured as input, the default signal level is still 0.

The pin in question is GPIO.03, which is called GPMI_CLE. Having a look at the mx23 manual, it appears to me that only a few GPIO pins have a built-in pullup resistor in the processor.

I simply can't believe it; could you please confirm or reject this? Furthermore, are there pullups on the PCB itself for certain pins?

Thanks, regards,
Tamas