Newb wants to build arduino tennis ball launcher

Community Projects
1

Hi all!

So I’m a total newb when it comes to electronics/programming but I really want to start learning how to prototype stuff using arduino. I’m hoping that some of you will be kind enough to help me get started. I want to make a tennisball launcher for my dog as a first DIY project. Silly, I know, but I want to start with something simple that will get me soldering and doing some arduino programming. A parts list would be extremely helpful!

So the idea is to train the dog to drop his ball in a hopper…this is actually the easiest part for me! The ball will roll down beyond the dogs ability to reach in (safety) where it will hit an activation switch and be held by a retention gate. The switch will activate the arduino program, which will start a single motor that will drive two small wheels (like a pitching machine). After the wheels are activated and turning fast enough (which I’ll determine using time, not any wheel speed detector), the gate will drop and the ball will go down the hopper a bit further and be fed into the wheels. Launch! The dog will then get the ball and drop it back into the hopper within one minute, at which point the process will repeat (sort of). I want to make it so that if the dog returns the ball fast enough, the motors won’t ever stop and the program will simply detect the ball, drop the gate, and launch again. If the dog decides he’s done and doesn’t return the ball to the hopper in time, the program will shut off the motor. The motor only needs to be strong enough to launch the ball about 30 feet.

So basically I need an arduino, the activator switch, the gate dropping motor/servo/?? (something that will drop the gate then return to its initial position), and a motor with enough power to get the job done. I can build the body and the mechanical stuff from scrap and thrift store finds. Am I missing anything? If anyone has any suggestions on what specific parts/specs/power requirements/?? I could use, I would be quite appreciative. As I said, I’m a newb and will be using this as an intro to making stuff with arduino, so cheap components would be fine. I have looked into parts and guides and things but frankly, there is soooo much info and soooo many parts that I’m not sure where to start. I’m hoping someone will read this and think, “oh, yeah, get this, this, this and this. Done”

Thanks a ton, I’m looking forward to tinkering!

2

…will be using this as an intro to making stuff with arduino

This project is quite a huge step for an intro into Arduino. The first thing you should do is get an UNO and some basic components that is related to this project. Start with the most basic aspect like getting a motor to turn and shut off after a period of time. Then move on to the next. You want to get just one aspect of your project working at a time, then when you have individual aspects working, start to integrate them together.

Another reason to do it this way is so you can figure out what components you actually need and to troubleshoot if you need to add anything to your project. If you jump in and try to get everything working all at once, the troubleshooting will much harder.

You can also dive into a Google search and see if anybody has done a similar project so you can learn from their mistakes. I am sure that you can find tutorials for spinning a motor of a particular size to get you started.

If you run into any issues while doing something, you can post your issue here and we can help.

3

I’d say the first thing to figure out is what motors are to be used. This will determine what you need for a power supply, what’s needed to control/switch the motors on and off. Then, if I understood the OP correctly, the rest is pretty easy. There needs to be a “ball present” detector (perhaps a simple switch), an Arduino controlled “gate” (which might be a servo or a solenoid, depending on the mechanical design) and a motor on/off “switch” (?FET or relay?). Add a power supply, an on/off switch and some flavor of Arduino (and maybe a horn to warn Fido) and you’re done. To me it’s more a mechanical design project than an electrical or software one.