In what we hope is a new trend in interviewing, some of the people at [Anthony]’s place of work asked him to make some wireless quiz buttons. He took the task quite seriously, making them extremely robust and low-power.
[Anthony] is experienced in the button arts, having made this party push button for a wedding reception. His design for the quiz buttons is a little different. Each button has an Arduino Pro mini and an nRF24L01 wireless RF module. On the receiver side is an Arduino Pro micro and an another RF module. A connected PC captures the serial data and displays the pressed button’s ID. It also shows the order in which subsequent buttons were pressed and the time elapsed between them.
The really notable part of this build aside from the awesome laser-cut MDF Devo energy dome button housings is the extremely low power consumption of the transmitting Arduinos. [Anthony] has designed them to go into sleep mode which disables all on-board circuitry and only wakes on interrupt. He removed the power LED and the voltage regulator since they run on 2-AA batteries. The voltage regulator was drawing more than 25mA in sleep mode. Because of these mods, each button consumes < 1μA, which is less power than the batteries can self discharge over their lifetime.
The four colored buttons seen above are a product made by Learning Resources. They flash and make noise when pressed and are meant for quiz-show style games in the classroom. The problem is that they don’t use a central controller, so it’s up to the person running the game to judge who rang in first. [Kenny] fixed that issue by building his own controller which is housed in that black project box.
He went with an Arduino Uno board. It fits in the project box and has no problem monitoring all of the buttons and triggering their sound and lights when necessary. There are two telephone jacks (RJ11 connectors) on either side of the controller. He also cracked open each button, cutting some traces on the PCB in order to patch the signals into connectors he added to the housing.
The video after the break shows the system in action, In addition to illuminating the first button to ring in there are LEDs on the box that indicate who was 2nd, 3rd, and 4th in line.
If you don’t want to purchase buttons try making your own with some cheap plastic bowls.
Continue reading “Hacking quiz game buttons to add a central controller”
Theses are the team buzzer boxes which [Philippe Chrétien] built for his mother. She’s a big fan of quiz shows (we’re thinking Jeopardy and the like) and he thought she’d enjoy a proper setup for home gaming.
Each unit consists of an arcade button and one LED, both housed in a project box. He uses telephone wire to connect each buzzer to the base unit. We like that idea since we’ve got a lot of old telephone cable lying around and our RJ-45 crimp includes an RJ-11 slot. This is perfect for making our own cables.
The base unit houses an Arduino board which polls the buttons to see which is pressed first. The LED on the appropriate buzzer box is illuminated so the players know who got in first. One special feature of this setup is the ability to choose from 30 different buzzer sounds.
There are several other quiz buzzer projects kicking around Hackaday if you’re interested. One of our favorites is this system which uses plastic bowls as the buttons.