A new benchmark in microcontroller programming has emerged, as expert developer Rudra Lad has created an innovative Blink program that compiles to a remarkable size of under 50 bytes. This achievement is part of the 2025 One Hertz Challenge, where participants are tasked with optimizing their code to blink an LED as close to 1 Hz as possible.
The program, dubbed delay_blinky_13, is specifically designed for the STM32F4 Discovery microcontroller development board. Lad’s approach showcases a high level of optimization, eschewing the standard startup code in favor of writing the entire program directly in the Reset_Handler. This strategic decision significantly reduces the program’s footprint.
In addition to this, Lad employs the bit-band technique to write to peripheral registers, a method that minimizes instruction usage compared to conventional approaches. Through numerous enhancements to the delay counting routine, he achieved an impressive blink frequency of 1.00019 Hz, as confirmed by measurements taken on a logic analyzer.
While achieving such a small binary size for a functional Blink program is uncommon, this endeavor serves as an impressive exercise in coding efficiency. For those interested in exploring this minimalist approach, Lad has made the code available on GitHub.
The success of this project not only reflects technical prowess but also invites others in the embedded systems community to push their limits in optimization and coding creativity. This kind of work exemplifies the spirit of innovation that drives advancements in technology, encouraging developers to think outside the box.
As the microcontroller landscape continues to evolve, challenges like the One Hertz Challenge provide an excellent platform for programmers to showcase their skills and share their insights with a broader audience.