I want to build a dog treat dispenser. I bought a Zevro dispenser, and have been following along with tutorials like this one http://www.robpeck.com/2017/11/robs-raspberry-pi-powered-cat-feeders/#.WzFrlS2ZOHp
The main difference between mine and theirs is that I’d like to keep the knob and use a motor and turn it (rather than replace it). I wanted to bolt a plastic disc with a servo to control it.
I’ve got a Raspberry Pi 3b and the Explorer Hat Pro. The hat works fine. I’ve run tests, and everything seems to work. However…
I’ve tried to connect up 2 different servos ( [sg90](http://akizukidenshi.com/download/ds/towerpro/SG90.pdf and hs-311 ) and neither of them seems to work, and I feel like I must be doing something wrong. Not sure how to debug.
I’ve got red to 5V, black to GRND, and yellow to the PWM of the Explorer hat.I’ve also installed pi-blaster. When I run ‘echo 18=0.2 > /dev/pi-blaster’ (following this) it returns immediately and nothing happens.
Do I need a resistor?
I’m not using one right now. If I need to use one, how do I know how strong of a resistor I need?
I have a gear motor working. Why use a servo instead?
I bought one from Pimoroni, and it works just fine when connected to motor outputs of the Explorer and it works fine. I’m not sure I understand why most people go the servo route. I only want to turn the motor on for a second or two at a time in 1 direction. The gear motor seems pretty powerful.
I’m pretty disappointed by the lack of resources around the Explorer Hat! I think I’m gonna write a post once I get things working.