The Official Raspberry Pi Projects Book - Projects_Book_v4

raspberrypi.org/magpi The Official Raspberry Pi Projects Book 57

DOG TREAT MACHINE Projects

>STEP-01

Cutting the parts

Eric used a laser cutter at a local makerspace to

create the plastic stand and cylinders. The inner

cylinder is divided into two compartments; one for

storage and one for dispensing.

>STEP-02

Dispensing mechanism

To make sure the desired number of treats falls into

the dispenser compartment, acrylic semicircles

reduce the size of the opening. One of these is

attached by Velcro and can be adjusted.

>STEP-03

Stepper motor

A stepper motor with driver board is used to rotate

the cylinder, causing the treats to fall out of the

opening, while allowing more treats to drop into

the dispenser compartment.

MAKE A DOG

TREAT DISPENSER

it for four to five months, adding
additional delivery mechanisms
and improving the reliability of the
code, e.g. reconnecting everything
if the WiFi went down.”
Eric says the most difficult part
of the project was getting the

device to deliver a small number
of treats (not zero or too many) by
gravity from its plastic cylinder,
when rotated by a stepper motor.
“The design went through several
iterations before I hit on the
concept of a cylinder with a central
storage area, with an adjustable

opening to a smaller section that

holds and dispenses one serving.”

Following the success of the

treat dispenser, Eric has extended

the project by building a ball

launcher using RFID-tagged balls,

which he’s trained Pickles to

retrieve and place in a receptacle

equipped with an RFID reader.

“Now Pickles can get his own

treats by putting those balls in

the receptacle. He loves it. Now,

he even sits by the ball launcher

making funny noises – his way of

saying ‘Dad, launch a ball!’.”

Now Pickles can get his own

treats by putting those balls

in the receptacle. He loves it

Eric reckons

Pickles thinks

of the device as

“some sort of

God of Treats.

Sometimes, we’ll

see him just

sitting in front of

it, looking up at

it with a mixture

of awe and

delight”

Below The

ingredients for

the perfect dog

treat dispenser

include a Pi,

Camera Module

laser-cut tubes

and stand, and

a stepper motor