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AD5668 support in Linux with ARM Cortex-A8

Question asked by bhaskar9966 on Apr 7, 2016
Latest reply on Apr 11, 2016 by bhaskar9966

Hi all,

 

Greetings !!!

 

I am interfacing EVAL-AD5668SDCZ with TI-AM335x EVAL Board.

I am using Linux-3.12.30.

 

I have done integration and driver compilation and successfully got sysfs entries also.

i am able to send the data to DAC register.

 

But the problem is I am not getting proper output voltage at TP4 (or) OUTPUTA.

I am following the below excellent wiki link from ANALOG DEVICES.

AD5064 IIO Quad-Channel DAC Linux Driver [Analog Devices Wiki]

 

I am getting only Maximum 197.2 mv at the output A.

I am using internal_vref = 2500000 , and below are the sysfs values.

 

$ echo 10000 > /sys/bus/iio/devices/iio\:device0/out_voltage0_raw

$ cat /sys/bus/iio/devices/iio\:device0/out_voltage0_raw

10000

$ cat /sys/bus/iio/devices/iio\:device0/out_voltage0_scale

0.038140

 

U = out_voltage0_raw * out_voltage0_scale = 10000 * 0,038140 mV = 381,14 mV

 

According to the above wiki link, i have to get 381.14mv  mv, but i am only getting 197.2v.

If I am giving 100 to out_voltage0_raw, I am getting 16 mV.

 

What could be the problem ? any jumper settings i have to check in  EVAL-AD5668SDCZ

 

could any body help me in this ?

 

Thank in advance.

 

Regards ,

Bhaskar

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