Overview

This is a documentation for 6.08 design exercise trivia game. This consists three different parts: overall design flow, server file(s) explanation, and state machines/any other details being implemented in src.ino.

The demonstration video is linked below demonstration video

1. Overall Design Flow

NOTE: You can change user name by changing `USER[]` in the code.

The LCD display mainly consists of four screens:

opening screen, which display current user name, historical statistics (ie.total score, total number of correct/wrong answers), and instruction to press button 38 to start a new game.
gaming screen, which transits from (1) by pressting button 38. It displays a local game score, number of correc/wrong answers (all starts with 0s), question, and instruction to press button 39 for answering True, button 45 for answering False, and button 38 to terminate the game and recalculate the historical total score. Note that pressing button 38 triggers a POST request to https://608dev-2.net/sandbox/sc/xieyi/trivia_score.py (more details in section 2).
By answering a question correctly/incorrectly, a corresponding screen saying "CORRECT" or "INCORRECT" will pop up for 400ms, then bring you back to screen (2).
The game cycles between 2 and 3 until the user presses button 38 to terminate the game. Note, my design choice is to only POST when a game is terminated because a user can spam True/False button and it does not make too much sense to POST every second.

2. Server File(s)

1. travia_request.py (https://608dev-2.net/sandbox/sc/xieyi/travia_request.py)

-> This server script simply handles a request to trivia API whenever it's called. It also processes the response from API and converting unicode apostrophes and quotes. It returns a JSON dictionary consisting of a question and a corresponding answer. -> To avoid repetitive questions, I randomly choose category from 9 to 12 in this file.

2. trivia_score.py (https://608dev-2.net/sandbox/sc/xieyi/trivia_score.py)

-> a) When there's a GET request with scoreboard = True, it displays a scoreboard, ranking from the highest to the lowest scores of all users in browser, which can be viewed here: (https://608dev-2.net/sandbox/sc/xieyi/trivia_score.py?scoreboard=True) -> b) When there's a GET request with score = True and a user argument, the script will look up in the database whether this user is in the database. If so, it will return the user's historical score (score, correct_num, wrong_num); else, it will return all 0s indicating there's a new user, and create another entry in the database. -> c) When there's a POST request, with score, correct_num, and wrong_num arguments, it will create a new row in the database if it is a new user, else it will only increment the corresponding user's existing entries. -> d) To make an HTML list, I have an extra function named ulify.

def ulify(elements):
    string = "<h2>Scoreboard</h2>\n"
    # string += "user\tscore\tcorrect number\twrong number\n"
    string += "<ol>\n"
    for x in elements:
        string += "<li>" + "User: "+str(x[0]) + ", Score:"+str(x[1])+", Correct:" + \
            str(x[2])+", Wrong: "+str(x[3]) + "</li>\n"
    string += "</ol>"
    return string

It essentially hard codes html tags into strings.

3. State Machines/Other Details

A state machine is implemented to handle transitions and make the game replayable. It consists of 8 states, with 5 waiting states to handle latency and button press.

In START state, it initalizes a GET request discussed in 2.2b to get historical stat with current user name, else it initalizes to 0s. It shows screen (1). On press button 38, it will go through WAIT_1 really quick and on release button 38 it goes into QUESTION state.

In QUESTION state, it sends a GET request once as discussed in 2.1. We process the JSON dictionary and display local stat, question, and instruction (screen (2)). -> By pressing button 39 to choose the answer is True, it goes through WAIT_2 to handle button release, then goes in CHECK_ANS. -> By pressing button 45 to choose the answer is False, it goes through WAIT_3 to handle button release, then goes in CHECK_ANS. -> By pressing button 38 to terminate the game and calculate the score, it goes through WAIT_4 to handle button release, sends a POST request once as discussed in 2.2c, and on release goes back to screen(1).

In CHECK_ANS, it compares if user answer is the same as the trivia answer. If so, it increments both score and num_correct by 1, and shows screen (3). Else, it decrements both score and num_incorrect by 1, and shows screen (3). Then, it resets and goes through WAIT_QUESTION -> QUESTION (back to screen (1)).

minzsiure/Trivia-Game