Vermes
Advanced Member level 4
It is a simple device for quiz games, which is based on microcontroller Attiny2313. It uses two large LED displays. The main task of the design is to indicate which player wanted to answer a question as the first person. There are also some additional visual effects, storing and changin points won by a player (in the range from 0 to 99) and a function which allows to indicate which player (or players) won the turn. It is also possible to run the sound indicator that the time for answer is up. That function means that when you set for example 5 seconds, a player reports and then there is a beep indicating that the 5 seconds passed. Program was written in Bascom.
Controller operates on an external oscillator 8MHz. Diodes in the display and four 10mm diodes are controlled multiplex, so they take 10 pins in total. Only one output instead of two outputs is used for enabling the keying transistors, because there is a NOT gate at one of those transistors. When high state appears at the output, the left digit is lit, when there is low state, the right digit is lit. Additional four inputs were used for connecting the buttons of players and one output was connected with the buzzer. 2 buttons were connected to the inputs, and the third button shorts both buttons using rectifying diodes.
Program was written in Bascom-AVR, it takes 99% of 2kb memory.
Electronics was based on two PCBs designed in Design Spark PCB. One of them pairs cathodes of displays to multiplexes and the second contains the entire electronics. The device is powered by four batteries AA (6V).
Filter on the display was made of windiws dimming foil. The electronics is closed in a housing made of a tin can which was previously painted black. Buttons for players were also made of tin cans. They are connected with the main board by 1 meter cables.
Video showing practical handling:
When the program is run, a few seconds animation appears. Then the system waits (dsplaying two dashes) for pressing the button by one of the players. At that point you can set the time for the player to press a button (when that time passes, you can hear a beep – when you set „00”, the time will be unlimited). The time is set using „up” and „down” buttons next to the display. When a button is pressed, the display shows the current value for a moment and returns to the standby mode (dashes). When the button is released quickly and pressed again, you can make changes. Quick increase/decrease the variable value can be done only when the user holds the button for at least one second. That makes it easier to precisely enter the desired value.
When you press the medium button in the standby mode, the device displays animation and indicates which of the players received the highest number of points (which may also indicate a tie) – the winner is indicated by 10mm LEDs while the number of points he received is showed on the LED display. When it happens, „up” and „down” buttons are disabled and the medium button can be used to return to the standby mode.
When the system is in the standby mode and one of the players presses the button, the device shows the number of points received by that person (and disables the buttons of the other players, what makes it possible to detect the difference of few miliseconds between the players). „up” and „down” buttons can be used for hanging the number of points and the medium button allows you to return to the standby mode.
Link to original thread - *Gra "teleturniej" na Attiny2313
