ESP32-A2DP VS AutoConnect

Whole thing is programmed using Arduino library in platformio and for a2dp sink im using pschatzmann library https://github.com/pschatzmann/ESP32-A2DP

The ESP8266 won’t work, since it doesn’t support Bluetooth. You’ll need an ESP32 and an I2S DAC. I built something similar based on this library: https://github.com/pschatzmann/ESP32-A2DP

I want to turn a USB computer keyboard into a musical instrument where i can press a key and a sound is played on my bluetooth speaker. I have played around with https://github.com/pschatzmann/ESP32-A2DP and managed to hardcode a little tune and play it on the speaker. Unfortunately that alone already uses 80% of the esp32 flash memory and I need some more space to read the keyboard input and do a little bit of sound design on top of that. I’m looking for suggestions on a controller (combination of controllers) would be best suited for the job, with the constraint that it should have low power consumption.

Check out arduino-audio-tools and other libraries it can make use of, such as ESP32-A2DP. It's tailored towards ESP32 devices, but also supports the RP2040 and others.

For all other i2s pinouts, I'm leaning on this GitHub-project: https://github.com/pschatzmann/ESP32-A2DP

You can use Bluetooth A2DP. This is the same standard used in Bluetooth headphones. Several implementations are available https://github.com/pschatzmann/ESP32-A2DP

A2DP library: https://github.com/pschatzmann/ESP32-A2DP

I recently discovered that the ESP32 could be used to receive audio via Bluetooth and since I'm using one as part of my build anyway (for controlling peripherals and LED outputs) I was thinking to just use the ESP32's onboard Bluetooth rather than a dedicated chip/module. After looking through some example code and the ESP32-A2DP library, I feel confident that this would work but is anyone able to see any caveats in doing this other than not being able to support aptx?

And for Wifi management on ESP32, this awesome repo that "does it all": https://hieromon.github.io/AutoConnect/ -- this repo creates its own access point you can connect to with your phone to pop-up a "captive portal" (like you see at hotels or airports) to enter your own Wifi credentials -- this is only done once -- after that, the ESP32 will connect to the last known good Wifi network. If you don't want that, just use the built-in Wifi functions to create a local Wifi hotspot to connect to. Then creating web pages on the ESP32 is easy -- you can use the "PageBuilder" JSON syntax, or host regular HTML/JS/CSS files on the SPIFF/LittleFS partition and server those in response to incoming requests.

Or if you don't want to have a hardcoded ssid and password in your program, you can use the AutoConnect library

I want the device to be portable, so I want the esp32 to automatically reconnect to Wi-Fi every time I switch it off and back on. I have used this library, and it serves the exact purpose of what I want to do in my project : https://github.com/Hieromon/AutoConnect

I want to save power on a battery powered sensor but I also want to have AutoConnect set up to set up and configure the wifi. Since having the wi-fi running it can take up a lot of energy I would like to make sure that none of the battery is used during the programming set up. I was thinking that the AutoConnect would only run when it detects that it is plugged into a 5v usb port. I also want a switch so that the usb can power either the sensor (lower power) or the wifi configuration (high power) parts of the program. How would I best accomplish this?

It is this one right: https://github.com/Hieromon/AutoConnect ?