Wind River Support Network


LIN5-18979 : ad7298 on ECS-gen2: the value "in_voltage0_raw" does not change when give AVIN0(R155) to an 5V voltge

Created: Jun 24, 2014    Updated: Dec 19, 2017
Resolved Date: Jul 7, 2014
Found In Version:
Fix Version:
Severity: Standard
Applicable for: Wind River Linux 5
Component/s: BSP - Async


I give the AVIN0 pin an  5V voltage and  could not see the in_voltage0_raw changed:
the value is hoped to be 2500, but it does not change and keep to be 2:

root@localhost:/sys/bus/iio/devices/iio:device0# cat in_voltage0_raw
root@localhost:/sys/bus/iio/devices/iio:device0# cat in_voltage0_raw

Steps to Reproduce

1) build an standard linux project with  bts layer and delpoy it on  ECS target
2) login in linux shell . generate an 5V voltage with I/O expander 
J18, Digital 0:
echo -n "50" > /sys/class/gpio/export
echo -n "out" > /sys/class/gpio/gpio50/direction
echo -n "1" > /sys/class/gpio/gpio50/value

I check the voltage of the J18, Digital 0 , about 4.95V

3)  connect  AVIN0 to the  J18 Digital 0, with an cable. 

4) see if the value changes:
     # cd /sys/bus/iio/devices/iio:device0
     # cat in_voltage0_raw

Other Downloads

Live chat