This Dog Owner Built an Alexa-Controlled Tennis Ball Launcher

Dogs — high-energy working dog breeds in particular — need a lot of exercise and mental stimulation. Fetch is popular because it is a great way to keep your dog active without having to run around yourself. But picking up a tennis ball and throwing it over and over again gets tiresome fast. You already know where this is going: why not build a machine that does all the hard work for you? That's exactly what YouTuber GSeph Electronics did with this Alexa-controlled tennis ball launcher.

This is essentially a tennis ball launcher, like the kind used for tennis practice, but designed for dog-friendly play time. GSeph first experimented with using a small hobby RC electric motor and tire to fling the ball. But that wasn't powerful enough and couldn't spin fast enough to throw a tennis ball more than a few feet. So he turned to something more powerful: a motor scavenged from a benchtop grinder. That motor is powerful, spins at a high speed, and has a grinder wheel that was abrasive enough to grip a tennis ball.

GSeph mounted that motor in an MDF box with some PVC pipe as chute to feed the tennis balls. A custom ESP32-based board controls the electric motor through a relay. A solenoid attached to the hopper tube keep the tennis ball in place until the ESP32 detects it with an infrared sensor. When it detects a ball, it dispenses some dog treats and then releases the tennis ball to launcher. The idea is that GSeph's dog will learn through positive reinforcement to put the tennis ball into the hopper himself. That hasn't been successful yet, but it is a solid idea. Because the ESP32 has WiFi, GSeph was able to connect it to an Amazon Alexa skill. Whenever he wants to activate the system, he can say "Alexa, play with the dog."