Sudoku UART Interface (for AVR)

Author: Odysseas Stavrou (canopus)

Prof: A. Dollas

The course on Embedded Systems (ACE411) at TU Crete had us develop a Sudoku Solver on an ATMega16 (Using the STK-500). So I wrote a small frontend / interface in Rust to interact with the STK-500 over UART.

Why

Because I wanted to learn more about Rust and I was definitely not going to be sending 81 Cells by hand using Putty

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The Interface has the following functionality:

• Generate Uniquely Solvable Sudoku Boards using the sudoku Crate
• Solve the board and remove Cells in order to create Difficulty Levels (whilst remaining Uniquely Solvable)
• Bulk Board Generation
• Download a board to the STK-500
• Receive Board and check solution
• Measure Time until receiving "Solve" signal
• Can Drop you into Interactive Shell suporting a specific Hayes Command Set
• Cross Platform (Windows / Linux) using the serialport-rs Crate
  • Variable UART Configurations (Data bits, Stop bits, etc) Provided by the Crate
• Export Current Board with time to solve

The interface has 4 modes:

• gen (Bulk Generate Boards)
• prog (Program a created board to the STK-500 and optionally drop into interactive shell)
• run (Same as above but generates a board at Runtime, drops into interactive shell afterwards)
• list (List available UART Ports)

The Hayes Command Set

Command	From	To	Response	Description
AT	PC	AVR	OK	Attention
C	PC	AVR	OK	Clear
P	PC	AVR	OK	Start Solving
D*	AVR	PC	S	AVR Done Solving
T	PC	AVR	N<X><Y><NUM>	AVR sends the contents of X,Y cell, PC replies with T to receive the next one
D*	AVR	PC	OK	AVR Done Sending Solved Board
B	PC	AVR	OK	AVR Stops any calculations
D<X><Y>	PC	AVR	N<X><Y><NUM>	AVR returns contents of X,Y Cell

Note that each Command and Response have "\r\n" in the end.

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Releases

You can find the latest release on the Release Tab.

Or you can Build it yourself.

Usage

• Available commands:

$ ./ace411_sudoku -h

ace411_sudoku 0.1.0

USAGE:
 ace411_sudoku <SUBCOMMAND>

FLAGS:
 -h, --help       Prints help information
 -V, --version    Prints version information

SUBCOMMANDS:
 gen     Generate Boards
 help    Prints this message or the help of the given subcommand(s)
 list    Lists Available Serial Ports
 prog    Download Board to MCU
 run     Run Mode

• List Available boards:

ace411_sudoku list

• Bulk Generate boards:

$ ace411_sudoku gen -h
Generate Boards

USAGE:
 ace411_sudoku gen --directory <directory> --number <number>

FLAGS:
 -h, --help       Prints help information
 -V, --version    Prints version information

OPTIONS:
 -d, --directory <directory>    Directory to place the Boards
 -n, --number <number>          Generate <number> boards for EACH
           difficulty level

• Download a Board to STK-500:

$ ace411_sudoku prog -h
Download Board to MCU

USAGE:
ace411_sudoku prog [FLAGS] [OPTIONS] --board-file <board> --baud-rate <br> --dev <dev>

FLAGS:
 -h, --help           Prints help information
 -i, --interactive    Enter Interactive shell
 -V, --version        Prints version information

OPTIONS:
 -b, --board-file <board>    Board file to download
 -r, --baud-rate <br>        Baudrate
  --data-bits <db>        Data Bits [default: 8]  [possible values: 5, 6, 7, 8]
 -u, --dev <dev>             Device Port
 -p, --parity <p>            Parity [default: None]
  --stop-bits <sb>        Stop Bits [default: 1]  [possible values: 1, 2]

• Run:

Run Mode

USAGE:
 ace411_sudoku run [OPTIONS] --baud-rate <br> --dev <dev> --difficulty <difficulty>

FLAGS:
 -h, --help       Prints help information
 -V, --version    Prints version information

OPTIONS:
 -r, --baud-rate <br>             Baudrate
  --data-bits <db>             Data Bits [default: 8]  [possible values: 5, 6, 7, 8]
 -u, --dev <dev>                  Device Port
 -d, --difficulty <difficulty>    Difficulty of Game [possible values: Easy, Medium, Hard, Ultra]
 -p, --parity <p>                 Parity [default: None]
  --stop-bits <sb>             Stop Bits [default: 1]  [possible values: 1, 2]

• Example Usage:
• Download Easy_1.txt board to an STK-500 in /dev/ttyUSB0 with a baudrate of 9600 and then drop into an interactive shell: ./ace411_sudoku -b Easy_1.txt -u /dev/ttyUSB0 -r 9600 -i
• Same as above but with Parity:
• ./ace411_sudoku -b Easy_1.txt -u /dev/ttyUSB0 -r 9600 -i -p Odd

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Build

Building is only supported in Linux due to required packages by the serialport-rs Crate (See Dependencies)

• Install Rust using rustup
• Install cargo make:
  • $ cargo install cargo-make
• Add windows target:
  • $ rustup target add x86_64-pc-windows-gnu
• Clone this repo
• $ cargo make sudoku
• Binaries will be available under out directory
• Profit?

Dependencies

The serialport-rs Crate requires pkg-config and libudev headers to be installed

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TODO

• Add UART functionality

• Send Unsolved Board

• Receive Solved Board and Check

• Await Responses Each time a write is issued

• Interactive Shell Conforming to the Hayes Command Set

• Replies when Necessary

• Help Menu For Shell

• Cross Platform UART Ports (serialport-rs)

• Add Difficulty Levels [Easy, Medium, Hard, Ultra]

• Randomly Remove Cells (Remaining Uniquely Solvable)

• Create Boards

• Printing

• Solving

• Explicit Board Generation

• Explicit Board Download to AVR

• Calculate Time until Solution arrives

• Argument Passing

• Anything else I find down the road

• Comments & Documentation

• Update README