tobrien81 wrote:OK, So I need a little help. I have connected my servo to RPi GPIO port 7, the driver loads fine and I get a character file in /dev called /dev/servoblaster. However when I type in echo 0=120 > /dev/servoblaster the servo does not move... Any ideas?
Apologies if these are simple-and-obvious points.
First, do you have a power supply for the servo
? I used 4 NiMH cells, giving me about 5V. Battery positive to the red wire, and battery negative (or Ground, GND or 0V) to the black wire. I recommend that you don't use the 5V supply output from the Pi, because servos can draw a lot of current.
Second, is the 0V line on the servo
connected to 0V or GND on the Pi? You must have a common ground between the Pi and the servo
Finally, are you sure you have the correct pin? The first servo
0) is on GPIO4, which is pin 7. It's the fourth from the left on the lower row. Next to that, pin 9, is GND.
I used this reference:
http://elinux.org/RPi_Low-level_periphe ... .28GPIO.29