TL;DR: I can do this in a matter of hours and, as a sign of commitment, I can actually do it completely *before* you even accept this bid. No strings attached, you can pay after that.
Hello, I have plenty of experience working with MCUs(especially freescale and STs families), especially with arm-based ones and lately with the esp8266 and esp32 family of microcontrollers. I've worked at Freescale Semiconductors for half a decade as an engineer.
This project, as you said, is quite simple. I can just do it in one day, and you can accept the bid and pay me if you're satisfied with the work. Let's talk about it.