Re: Testing ti_am335x_adc continuous mode (WAS: Re: [PATCH 2/2]

["Zubair Lutfullah :" <zubair.lutfullah@gmail.com>]

On Mon, Oct 07, 2013 at 01:53:17PM +0200, Sebastian Andrzej Siewior wrote:
> Hi Zubair,
> 
> I have here am335x-evm board. The output of voltage4 (via `cat
> /sys/bus/iio/devices/iio\:device0/in_voltage4_raw´) returns values in
> the range 570…580. I tested the continuous sampling mdoe by executing
> the following commands:
> 
> |echo 1 > /sys/bus/iio/devices/iio\:device0/scan_elements/in_voltage4_en
> |echo 25 > /sys/bus/iio/devices/iio\:device0/buffer/length
> |echo 1 > /sys/bus/iio/devices/iio\:device0/buffer/enable
> |sleep 1
> |echo 0 > /sys/bus/iio/devices/iio\:device0/buffer/enable
> |cat /dev/iio\:device0 > iio
> |hexdump -C iio
> 
> and the output is:
> |00000000  37 02 92 02 1f 07 0a 06  20 06 31 06 2f 07 2a 07
> |00000010  2b 07 2d 07 2c 07 28 07  2c 07 2b 07 2b 07 0c 06
> |00000020  21 06 32 06 2e 07 2c 07  2a 07 2a 07 2c 07 2b 07
> |00000030  29 07 27 07 28 07 29 07  2a 07 0d 06 21 06 35 06
> 
> The first entry is in the range that I would expect. The second is
> slitghly higher. The third and following entries are out of range. Have
> you observed something like that? Is my testing close to what you have
> done or did I make an mistake here?

I can't read the hex dump easily..

Keep in mind that the driver now uses 16 bit storage. 

Also, I used generic_buffer.c after removing the trigger checks.

The driver would report stable values for 1.8V on one channel and gnd
on another channel.

Hope this helps
ZubairLK

> 
> Sebastian
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html