I got my hands on the this cheap demo board a few years ago. It is made by AI-Thinker which is a licensed manufacturer of modules based on WiFi/Bluetooth enabled microcontrollers made by Espressif.

📌 8051 Interrupts – Description An interrupt is a mechanism by which the 8051 microcontroller can temporarily halt its main program to execute a special routine (called Interrupt Service Routine – ...

The intel 8051 series 8bit microcontroller, originally introduced in 1980, remains popular and has had perhaps the longest product life of all such devices. It has become the industry standard for ...

Some people think that programs for microcontrollers like the 8051 that have limited program memory must be written in assembly language rather than a high-level language like C. The executable code ...