Most complex snake ever !!!!

Hi guys !

First of all, if you haven’t done yet, please check out our presentation topic where you will find a trailer of the game and a download link of the map.
In this topic, I will explain you how the game works and what components have been use in the auxiliary screen of the Snake.

There is also another topic who deal with main screen and its features, that is to say, the gameplay part.
You will find all URL below:

• Presentation topic : [URL ADDRESS]
  
• Explanations topic I (Main screen) : [URL ADRESS]
  

I – Score

A – Combo system



That component follows the rule: “The faster you are, the bigger you earn”:

• At the 1^st eaten food, you earn 1 pts and you must eat the 2^nd under 15s.
  
• At the 2^nd eaten food, you earn 10 pts and you must eat the 3^rd under 13s.
  
• At the 3^rd eaten food, you earn 20 pts and you must eat the 4^th under 11s.
  
• At the 4^th eaten food, you earn 40 pts and you must eat the 5^th under 9s.
  
• At the 5^th eaten food, you earn 80 pts and you must eat the 6^th under 7s.
  
• At the 6^th eaten food, you earn 160 pts and you must eat the 7^th under 5s
  
• At the 7^th eaten food, you earn 320 pts.
  

If you don’t reach the next objective or if you just have eaten the 7^th food, the combo will be reset.
Notice that your body can’t exceed a size of 15, so basically, the biggest score is 1263 pts.

Composition

• 1 * FIFO of 6 nibble (3 bytes)
  
• 3 * BCD adder
  
• 1 * 3 bits decoder
  
• 2 * modulo 7 counter
  

B – Storage of the record for each level

It saves the actual score only if the actual score is greater than the old one for a given level.
The record number is 3 digits so 12 bits.

Composition

• 3 * BCD comparator
  
• 1 * 180 bits RAM (size of the data (=12) * number of data (=15))
  

II – Cursor and menu

A – 3 dimension coordinates limiters

You can’t overpass the limit of the screen no matter where you are. It can for each menu (z-position) ,each line (y-position)  and for each x-position limit the x-position of the cursor. It can also limit the y-position for each menu(z-position), each line(y-position) and for each x-position.

Composition

• 1 * modulo 3 counter (y-position)
  
• 1 * modulo 8 counter (x-position)
  
• A lot of AND gates
  

B – Function’s caller

If it wasn’t here, click will be useless. It calls differents functions (back to the main menu, launch the actual level, play, pause) depending on the x,y and z position of the cursor and the state of the validation’s bits.

Composition

• Only AND gates
  

C – Menu

III – Level’s editor

It allows you to create your own map!
Firstly, you have to choose the layer you want to edit and then, you just have to place walls wherever you want! You can also place the spawn location (x-position: layer 8, y-position: layer 9).
The landmark for creating your level is:

Composition

• 1 * modulo 10 counter (8 layer for the walls + 2 layer for the spawn)
  
• 80* T Flip-flop
  
• 2 * matrix 10 x 8
  

IV – Means of communication (with the main screen)

The snake uses 3 kinds of communication:

• Serial bus for the edit mod (1 bits per 0.4s)
  

          - Waiting time: 36s (9*10*0.4)
          - 1 bytes + 1 starting bits
          - 10 layer (8 + 2)

• Signal strength for the 15 levels of the hard mod
  

          - 15 levels (15 different states for the strength)
          - Waiting time: 1.6s (4*0.4)

• And bits flag for monitor several units (serial receptor for example)
  

          - Reload level
          - Reset game
          - Play/Pause

Composition

• Receiver/Transmitter strenght signal
  
• Receiver/Transmitter serial bus
  

PS : Poste provisoire