Comment by icoder

Cool! I'm working on something comparable, but with the audio stored on a single SD and playback triggered using an RFID tag that we can than stick on wooden figures made by my GF (or anything 3D printed).

I'm still iterating over hardware, realising Pi Zero is a bit of overkill, using too many NiMH batteries in series may actually break those batteries, that ESP8266 has much less GPIO's available than the module design suggests, among other lessons learned.

My current approach is Pi Pico (ESP32 was the alternative) with a DfPlayer Mini and a 32GB SD card.

The DfPlayer isn't too keen on running on 3v3 from cheaper LDO's (which are on the modules I'm using) so my current approach uses a small power bank. That just offloads the hard part (for me) of battery management to the professionals. This weekend I added a few resistors and a transistor to draw extra power (0.5secs every 20 seconds) to keep the power bank awake.

But I have different LDO's and an ESP32 coming in, so it's not fully decided yet. Will for sure scan this thread and OP's article for more ideas!