Sanity check on my project

Hey everyone,

I’m very much a beginer in electronics and would appreciate a sanity check on a project idea before I go too far down the rabbit hole

This would be only my second project. My first one was a simple setup with a PIR sensor triggering a DFPlayer to play ambient music when someone walks into a room — it works, but I already learned a lot about “what can go wrong”

The idea

I want to build a small soccer goal for my 2-year-old nephew that:

* Plays a continuous crowd/ambient stadium sound
* When a goal is scored:
* Detects the ball entering the goal
* Stops the crowd sound
* Plays a random celebration audio (recorded by family members)
* Then goes back to the crowd loop

I would buy an existing hard plastic goal and adapt.

approach

Detection

* Planning to use IR break beams across the goal
* maybe 2 beams at different heights to improve the chance to sense the goal

Basic logic idea:

* If 1 or more beams are broken within a short time window → count as a goal

Audio

* Using a DFPlayer Mini
* Files on SD card:
* 001 = crowd loop
* 002+ = celebration sounds
* On goal:
* Stop loop
* Play random celebration
* Resume loop

Controller

* Arduino Nano (since I already used it before)

My concerns (would love feedback)

1. Detection reliability

* Is the multi-beam approach overkill or actually necessary?
* Any better way to detect a ball entering a small goal reliably?

2. False positives / weird behavior

* Ball bouncing inside the goal
* Kid sticking hand through beams
* Partial beam breaks

3. Audio limitations

* I know DFPlayer can’t play two sounds at once
* My plan is to stop ambient → play goal → resume

Is there a better/simple way to handle this?

4. Durability (big one)

This will be used by a toddler, so:

* Kicks
* Pulling wires
* Dropping the goal

Plan:

* Everything inside a box
* Sensors embedded in the frame
* No exposed wiring

Anything I’m underestimating here?

5. Power / safety

This is a toy for a 2-year-old.

What I’m considering:

* 4x AA batteries rechargeable
OR USB power bank

My concerns:

* Battery life (it may stay on for long periods playing ambient sound)
* Simplicity (I don’t want something that requires frequent charging or is easy to misuse)
* Robustness (needs to survive drops and rough handling)

Questions:

* What’s the safest and most “toy-kid-friendly-appropriate” power solution here?
* Are power banks actually a good idea for something like this?

6. General complexity

Am I:

* Building something reasonable for a beginner
or
* Creating a nightmare for myself?

🙏 What I’m looking for

* “This will work” vs “this will be painful”
* Simpler alternatives I might be missing
* Best/safest way to power this (especially for a kid’s toy)
* Common pitfalls (especially with IR beams / DFPlayer / Power)

Appreciate any feedback.

Thanks!