Re: [Gumstix-users] using gumstix line 34/39 on the robostix as GPIO

[Dave H. <dhy...@gm...>]

Hi Chris,

On 4/27/06, Chris Sears <chr...@gm...> wrote:
> > Just out of curiosity, what are you planning on using the GPIO lines
> > for? I'm curious why you wouldn't use GPIO lines on the robostix.
>
> I am using three PWMs on the robostix, one for a motor, one for a
> servo and one from a conversion start signal for an 8-channel I2C ADC.
>  The CONVST PWM signal takes a coherent picture of all of the analog
> signals.  I'm also sending this PWM signal into gpio 34 to signal an
> interrupt and wake up a process.  I'll be using char-driver for this.
> The polling process then reads the I2C ADC channels.
>
> The basic reason for not using the robostix for GPIO is that I need
> the PWM interrupt line coming into the gumstix.

Line PE2 on the robostix connects thru the voltage converter to GPIO
69 (LDD11). You could use that, and just have the conversion start PWM
generate an interrupt on the robostix which causes PE2 to be asserted.

I'm assuming that you'll be using edge triggered IRQ on the gumstix
side, so you only need to generate a narrow pulse.

--
Dave Hylands
Vancouver, BC, Canada
http://www.DaveHylands.com/