# The Shocker Buzzer for Trivia Games (feat. @Kouman ) Source: https://www.youtube.com/watch?v=AsJquvKz07E Recap page: https://rapidrecap.app/video/AsJquvKz07E Generated: 2025-10-17T16:34:36.658+00:00 --- ## Quick Overview Mehdi Sadaghdar, host of ElectroBOOM, successfully modifies a four-player electric shock trivia buzzer game by replacing its internal microcontroller with his own custom board, creating a more complex and fair game logic that incorporates external interrupts and PWM signals for controlled light and sound effects, ultimately demonstrating the superior electronic control possible over the original toy's simpler circuit. **Key Points:** - Mehdi Sadaghdar modifies a four-player electric shock trivia buzzer game by replacing the original control board with a custom microcontroller board. - The original game logic is reverse-engineered, revealing that the host's button controls the timer and high-voltage power supply, while player buttons trigger external interrupts to the microcontroller. - The custom circuit uses J-K Flip-Flops and logic gates to determine the first player to press their button, punishing subsequent presses by activating the shock mechanism. - The host demonstrates the high-voltage output reaching 156.32V DC using an oscilloscope, confirming the shock potential is significant. - The new software allows for complex game states, custom light/sound responses per player, and precise control over shock intensity via PWM signals. - The video concludes with a successful demonstration where the host punishes the contestants for pressing buttons too early or too late, highlighting the improved fairness and control of the custom system. ![Screenshot at 0:48: Mehdi Sadaghdar explains the initial setup of the game where the contestants \(Mia, Kourosh, and Iman\) are physically holding the shock handles while he stands behind the computer.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-00-48.png) **Context:** The video features Mehdi Sadaghdar from ElectroBOOM, who is reviewing and subsequently hacking a commercial four-player electric shock trivia game called 'Lightning Reaction'. The game involves players holding metal handles and pressing buttons to answer trivia questions, with the last person to press or anyone pressing too early getting shocked. Mehdi intends to reverse-engineer the device and replace its simple internal logic with a custom microcontroller setup to demonstrate superior, fairer control over the game mechanics. ## Detailed Analysis Mehdi Sadaghdar begins by showing the 'Lightning Reaction' trivia game, which involves four players holding handles connected to a central unit, and pressing corresponding colored buzzers. After the contestants play a round, resulting in chaos and laughter, Mehdi takes the device apart to investigate its electronics, noting a small microcontroller board inside. He then explains the original, simple logic: the host's button resets the game, and player buttons trigger external interrupts that control the buzzer and light/shock outputs. Using an oscilloscope, he measures the voltage spikes generated by the inductor circuit, finding pulses as high as 156.32V DC. To gain finer control, Mehdi replaces the original board with his own custom microcontroller circuit, outlining the new schematic on a whiteboard, which incorporates J-K Flip-Flops and logic gates to ensure only the first correct press registers and others are penalized with a shock or muted. He programs the custom board using Arduino-like code to manage inputs (player buttons, host button, reset switch) and outputs (LEDs, buzzers, and the high-voltage shock driver). After successfully programming and wiring his custom logic, he tests the game, demonstrating that he can now precisely control which player gets shocked and when, proving the superiority of his custom digital circuit over the original hardware. ### Game Introduction & Initial Play - Contestants Mia, Kourosh, and Iman play the original 'Lightning Reaction' game, which results in chaotic button pressing and immediate shocks for early presses (0:04-0:37). ### Reverse Engineering the Device - Mehdi disassembles the device, revealing a small green PCB controlled by a microcontroller and measuring the high-voltage output pulses (up to 156.32V DC) with an oscilloscope (0:44-1:04, 5:24-5:57). ### Custom Circuit Design - Mehdi draws a complex schematic on a whiteboard showing J-K Flip-Flops, AND/OR gates, and external interrupt inputs used to implement precise control logic for the four players and the host (3:43-4:19). ### Software Implementation & Sponsorship - Mehdi promotes Brilliant.org, showcasing interactive lessons on Digital Circuits and Programming with Functions, emphasizing that custom logic makes the game fairer (4:23-7:54). ### Reassembly and Testing - Mehdi hot-glues his custom board into one half of the buzzer housing and connects the components, explaining that the new system allows him to control the shock level and timing precisely (8:05-8:59). ### Final Demonstration and Conclusion - The host initiates a new round using his custom circuit, demonstrating that the system successfully penalizes players who press too early or fail to hold their handles, concluding that his custom circuit offers better control than the original (10:20-11:31, 12:55-14:41). ![Screenshot at 0:01: Mehdi Sadaghdar introducing the video from his workshop area, surrounded by storage bins.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-00-01.png) ![Screenshot at 0:06: The three contestants \(Mia, Kourosh, and Iman\) sitting at the table with the connected shock buzzers ready to play.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-00-06.png) ![Screenshot at 0:30: Mehdi Sadaghdar standing behind the contestants, explaining the rules while they react dramatically to the game's premise.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-00-30.png) ![Screenshot at 1:32: The contestants reacting with shock and laughter after a round of the electric buzzer game.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-01-32.png) ![Screenshot at 3:53: Mehdi Sadaghdar displays the complex logic diagram for the custom circuit built around J-K Flip-Flops on a whiteboard.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-03-53.png) ![Screenshot at 5:24: Mehdi connects multimeter probes to the disassembled internal circuit board, measuring the high voltage output.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-05-24.png) ![Screenshot at 7:06: Mehdi drawing the circuit diagram on the whiteboard, illustrating the high-voltage boost converter using an inductor and MOSFET.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-07-06.png) ![Screenshot at 9:44: A close-up shot of the custom microcontroller board wired up on the table next to testing equipment.](https://ss.rapidrecap.app/screens/AsJquvKz07E/00-09-44.png)