PWM script for raspbian


 
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# 1  
Old 07-25-2014
PWM script for raspbian

Hello Community,

I'm a little new to shell scripting and i was trying to write a servo control script for my Raspberry PI, using raspbian.

here is the code.

Code:
#!/bin/sh
#Signal time
signal_time_gpio27=0.0015s
#Delay time
signal_delay_gpio27=0.02s


if 
grep -lq 0 /sys/class/gpio/gpio27/value 
then
echo 1 >/sys/class/gpio/gpio27/value | 2>/dev/null
while true
do
sleep $signal_time_gpio27
echo 0 >/sys/class/gpio/gpio27/value | 2>/dev/null
sleep $signal_delay_gpio27
echo 1 >/sys/class/gpio/gpio27/value
done
else
echo 0 >/sys/class/gpio/gpio27/value | 2>/dev/null
echo "ERROR! Output is 1 - reset to 0"
echo "Current output:"
cat /sys/class/gpio/gpio27/value
fi

Unfortunately the servo does not move..

teach me masters


regards,

drux
# 2  
Old 07-26-2014
Not sure if the pipe will influence or not the redirection to /sys/.../value...
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