From Arduino to ESP-IDF: The architecture behind my digital "Swiss Army Knife"

1. Why build another multi-tool? How many of you have often found yourselves wanting to buy a Flipper Zero? I thought about it many times, but there were always problems holding me back: stock is often limited, the price tag is quite high, and above all, you miss out on the thrill of building such a powerful tool literally from scratch. From these observations, my project was born: designing and developing a low-level "Swiss Army Knife". It all started a few months ago. I was thinking about buying an M5Stick S3 after watching some videos online where people spoke very highly of it, especially for one major detail: unlike the Flipper, it has Wi-Fi and Bluetooth modules already built-in. Digging deeper, I quickly realized the advantages of the ESP32-S3 over the classic Arduino. The key features that convinced me were: Dual-core processor: It opens the door to serious features, like managing firmware tasks separately. More RAM: It allows integrating very complex external libraries (like heavy graphical interfaces) without killing performance. Native USB HID: It allows emulating peripherals like keyboards or mice natively and quickly. So, the hardware was decided. But why build a multi-tool? The main reason is to explore and understand the technical background of as many tools as possible. Lately, I feel there is a tendency to overlook the ingenuity of the mechanisms operating right in front of our eyes. We prefer having a ready-made tool, usable perhaps without even knowing the basics of computer science. I wanted to go in the opposite direction and understand exactly how these things work at the code level. 2. Fluid Graphics and Multitasking: How not to blow up an ESP32 A major problem when rendering a graphical interface on a microcontroller is that the CPU has to calculate and send every single pixel. Since this is a time-consuming operation, the entire device gets blocked until the whole interface is completely redrawn. In a multi-tool, if the ESP32 is stuck drawin