2025 One Hertz Challenge: A 4-Function Device for Measuring Frequencies
In the realm of electronic engineering, a remarkable creation has emerged—a four-function frequency counter designed by Jacques Pelletier, showcasing a unique blend of old-school techniques and modern CMOS chips.
The construction of this frequency counter is thoroughly old-school, eschewing modern technologies like code and RAM. Instead, it relies solely on raw logic chips, with no microprocessors or microcontrollers involved. The heart of the counter consists of 4553 BCD (binary-coded decimal) counter ICs and 4511 BCD-to-7-segment decoder ICs, both CMOS chips designed for digital counting and display tasks.
These counter chips count incoming frequency pulses in BCD format, while the decoder ICs convert this BCD count into signals that drive classic 7-segment LED displays. The timing for the sampling intervals (1 Hz or 0.1 Hz) is generated from an 8 MHz oscillator, enabling the counter to function as a frequency meter, period meter, chronometer, or a basic counter.
The design is a testament to classical digital electronics, where logic chips are combined to achieve complex measurement tasks directly in hardware rather than through embedded processors. The frequency counter was built using a mix of CMOS chips and smart design, demonstrating that even in an era dominated by software and microprocessors, the principles of traditional electronics can still yield impressive results.
Jacques Pelletier embarked on this project some time ago, when electronic parts were still readily available in local stores. His creation, humble yet capable, is now an entry into the 2025 One Hertz Challenge, a testament to its enduring relevance in the world of electronics. It serves as a reminder that the essence of engineering—innovation, creativity, and problem-solving—remains unchanged, even as technologies evolve.
The frequency counter, although designed with old-school techniques, is not entirely devoid of technology, as it incorporates CMOS chips in its construction.Despite the era being dominated by software and microprocessors, the four-function frequency counter demonstrates that the principles of traditional electronics using logic chips can produce impressive results, without any microcontrollers involved.
