Raspberry Pi Forums

Good afternoon I am very new to electronics and programming, I have been trying to install servo blaster on my raspberry pi to run a couple of servos on a pan and tilt mechanism but i am unable to get them working

I have been using this blog as a guide

http://computers.tutsplus.com/tutorials ... -mac-57052

the following a re the commands i used. echo is simply unresponsive.Can any one point out what i am doing wrong? It wouldbe a great help.

wget https://github.com/richardghirst/PiBits/zipball/master
mv master pibits.zip
unzip pibits.zip #unzip the code

pi@raspberrypi ~/PiBits/ServoBlaster/user $ sudo make install
[ "`id -u`" = "0" ] || { echo "Must be run as root"; exit 1; }
cp -f servod /usr/local/sbin
cp -f init-script /etc/init.d/servoblaster
chmod 755 /etc/init.d/servoblaster
update-rc.d servoblaster defaults 92 08
update-rc.d: using dependency based boot sequencing
/etc/init.d/servoblaster start
pi@raspberrypi ~/PiBits/ServoBlaster/user $ sudo etc/init.d/servoblaster
sudo: etc/init.d/servoblaster: command not found
pi@raspberrypi ~/PiBits/ServoBlaster/user $ make servod
make: `servod' is up to date.
pi@raspberrypi ~/PiBits/ServoBlaster/user $ ./servod

Board revision: 2
Using hardware: PWM
Using DMA channel: 14
Idle timeout: Disabled
Number of servos: 8
Servo cycle time: 20000us
Pulse increment step size: 10us
Minimum width value: 50 (500us)
Maximum width value: 250 (2500us)
Output levels: Normal

Using P1 pins: 7,11,12,13,15,16,18,22
Using P5 pins:

Servo mapping:
0 on P1-7 GPIO-4
1 on P1-11 GPIO-17
2 on P1-12 GPIO-18
3 on P1-13 GPIO-27
4 on P1-15 GPIO-22
5 on P1-16 GPIO-23
6 on P1-18 GPIO-24
7 on P1-22 GPIO-25

servod: Failed to open /dev/mem: Permission denied
pi@raspberrypi ~/PiBits/ServoBlaster/user $ echo 0=120> /dev/servoblaster
[1] 3157
0=120
bash: gt: command not found
[1]+ Done echo 0=120
bash: /dev/servoblaster: Permission denied
pi@raspberrypi ~/PiBits/ServoBlaster/user $ echo 0=60>/dev/servoblaster
pi@raspberrypi ~/PiBits/ServoBlaster/user $ echo 1=60 > /dev/servoblaster

servod: Failed to open /dev/mem: Permission denied

Permission denied generally means you're running something as pi (or another normal user) that you don't have permissions to. I'm not sure why you're trying to access /dev/mem, but if this is the right thing to do and is causing your issue, you can try it with sudo.

echo 0=120> /dev/servoblaster
[1] 3157
0=120
bash: gt: command not found

Instead of ">" you want an ">" there. Notice you got "0=120" on the screen, which means it didn't go to /dev/servoblaster as you intended, and then bash complained about gt, because it thought that was a new command you were adding to the echo command. ">" will redirect the output of echo to /dec/servoblaster, which is what you want.

well I used that syntax too but the servos were unresponsive

pi@raspberrypi ~/PiBits/ServoBlaster/user $ echo 0=60>/dev/servoblaster
pi@raspberrypi ~/PiBits/ServoBlaster/user $ echo 1=60 > /dev/servoblaster