Re: OMAP5912 touchscreen irq not working

David Brownell
2006-05-27T22:14:53Z

On Saturday 27 May 2006 1:10 pm, Imre Deak wrote:

> I noticed that the ads7846 sampling rate is set too high in board-osk.c.
> The spec allows a maximum bus frequency of 2.5MHz which gives a ~96k
> sample rate.

The spec says max sample rate of 125 KHz (at 5V) and describes Fclk
in terms of Fsample (at an extremely fast 16 bit/sample rate) ...
I saw no limit for Fclk, it's a function of the sample rate.

Regardless, the max sample frequency at 3V is not 96 KHz! The
graph shows 120 KHz... 96 KHz would be for about 2.1V.

> There is also the uwire clock patch in my previous post,
> which might have an effect on this issue.

Unlikely; it worked before, why would it stop working suddenly?
Including with the previous SPI clock... it's some other change
causing the breakage.

- Dave