pov.py

from __future__ import print_function
import os

characters = {
    'A' : ['0xE0','0xDB','0xBB','0xDB','0xE0'],
    'B' : ['0xF9','0xC6','0xB6','0xB6','0x80'],
    'C' : ['0xDD','0xBE','0xBE','0xDD','0xE3'],
    'D' : ['0xE3','0xDD','0xBE','0xBE','0x80'],
    'E' : ['0xB6','0xB6','0xB6','0xB6','0x80'],
    'F' : ['0xBF','0xB7','0xB7','0xB7','0x80'],
    'G' : ['0xF3','0xB5','0xB6','0xBC','0xC3'],
    'H' : ['0x80','0xF7','0xF7','0xF7','0x80'],
    'I' : ['0xBE','0xBE','0x80','0xBE','0xBE'],
    'J' : ['0x81','0xFE','0xFE','0xFE','0xFD'],
    'K' : ['0xBE','0xDD','0xEB','0xF7','0x80'],
    'L' : ['0xFE','0xFE','0xFE','0xFE','0x80'],
    'M' : ['0x80','0xDF','0xEF','0xDF','0x80'],
    'N' : ['0x80','0xF9','0xE3','0xCF','0x80'],
    'O' : ['0xE3','0xDD','0xBE','0xDD','0xE3'],
    'P' : ['0xCF','0xB7','0xB7','0xB7','0x80'],
    'Q' : ['0xE2','0xDD','0xBA','0xDD','0xE3'],
    'R' : ['0xDE','0xAD','0xAB','0xB7','0x80'],
    'S' : ['0xD9','0xB6','0xB6','0xB6','0xCD'],
    'T' : ['0xBF','0xBF','0x80','0xBF','0xBF'],
    'U' : ['0x81','0xFE','0xFE','0xFE','0x81'],
    'V' : ['0x83','0xFD','0xFE','0xFD','0x83'],
    'W' : ['0x80','0xFD','0xFB','0xFD','0x80'],
    'X' : ['0xBE','0xDD','0xE3','0xDD','0xBE'],
    'Y' : ['0x8F','0xEF','0xE0','0xEF','0x8F'],
    'Z' : ['0x9E','0xAE','0xB6','0xBA','0xBC'],				    
    '0' : ['0xC1','0xAE','0xB6','0xBA','0xC1'],
    '1' : ['0xFF','0xFE','0x80','0xDE','0xFF'],
    '2' : ['0xCE','0xB6','0xBA','0xBC','0xDE'],
    '3' : ['0xB9','0x96','0xAE','0xBE','0xBD'],
    '4' : ['0xFB','0x80','0xDB','0xEB','0xF3'],
    '5' : ['0xB1','0xAE','0xAE','0xAE','0x8D'],
    '6' : ['0xF9','0xB6','0xB6','0xD6','0xE1'],
    '7' : ['0x9F','0xAF','0xB7','0xB8','0xBF'],
    '8' : ['0xC9','0xB6','0xB6','0xB6','0xC9'],
    '9' : ['0xC3','0xB5','0xB6','0xB6','0xCF'],
    ':' : ['0xFF','0xFF','0xC9','0xC9','0xFF'],
    '!' : ['0xFF','0xFF','0x86','0xFF','0xFF'],
    ',' : ['0xFF','0xFF','0xF9','0xFA','0xFF'],
    '-' : ['0xFF','0xF7','0xF7','0xF7','0xFF'],
    ' ' : ['0xFF','0xFF','0xFF','0xFF','0xFF'],
}

header = """\
//This sketch was created using the pov.py module to 
//fill the I2C EEPROM on the POV fan
//
//LED on Pin 13 blinks once data transfer is complete
//
//Connections required:
//	Fan			Arduino
//	DATA  <--->	Analog Pin 4
//	CLK   <--->	Analog Pin 5
//	Vcc   <--->	3.3V
//	GND   <--->	GND


#include <Wire.h>

void setup()
{
  Wire.begin();        // join i2c bus (address optional for master)
  pinMode(13, OUTPUT);    
}

void loop()
{ 
"""

footer = """\
  Wire.endTransmission();

  while(1){
    digitalWrite(13, HIGH);   // set the LED on
    delay(1000);              // wait for a second
    digitalWrite(13, LOW);    // set the LED off
    delay(1000);              // wait for a second
  }
}
"""

class POV():    
    """
    :param screens: Screen contents
    :type screens: list of strings
    :param name: Folder/File name for Arduino sketch
    :type name: string
    """        
    def __init__(self, screens, name='pov_sketch'):
        self.screens = screens
        self.name = name     
        self.check_inputs()
        
        self.address_counter = 0
        self.i2c_address = '0x50'
        
        if not os.path.isdir(name):
            os.mkdir(name)
        
        self.sketch = open(name + '/' + name + '.ino', 'w')
        self.sketch.write(header)
        self.sketch.write('  Wire.beginTransmission(' + str(self.i2c_address) +  ');\n')
        self.sketch.write('  Wire.write(' + str(self.address_counter) + ');\n')
        self.sketch.write('  Wire.write(' + str(len(screens)) + ');\n')
        self.increment_address()
        
        for screen in self.screens:
            self.write_screen(screen)
        
        self.sketch.write(footer)
        self.sketch.close()

    def check_inputs(self):
        #Convert all characters to uppercase
        for idx,screen in enumerate(self.screens):
            self.screens[idx] = screen.upper()        
        
        #Drop screens with invalid characters
        for screen in self.screens:
            try:
                for letter in screen:
                    characters[letter]
            except KeyError:
                print('Bad character: ' + letter)
                print('\tDropping screen: ' + screen)
                self.screens.remove(screen)
        
        #Drop screens with too many characters
        for screen in self.screens:
            if len(screen) > 20:
                print('Max number of letters is 20')
                print('\tDropping screen: ' + screen)
                self.screens.remove(screen)
        
        #Drop screens if too many provided
        if len(self.screens) > 6:
            print('Max number of screens is 6')
            while len(self.screens) > 6:
                print('\tDropping screen: ' + self.screens.pop())
        
        print('Valid Screens:')
        print(self.screens)

    def increment_address(self):
        self.address_counter += 1
        if self.address_counter >= 256:
            self.i2c_address = '0x51'
        if self.address_counter >= 511:
            print('Error: Too much data...shorten messages')
            raise(Exception)
    
    def check_page_break(self):
        if self.address_counter % 16 == 0:
            self.sketch.write('  Wire.endTransmission();\n')
            self.sketch.write('  delay(500);\n')
            self.sketch.write('  Wire.beginTransmission(' + str(self.i2c_address) + ');\n')
            self.sketch.write('  Wire.write(' + str(self.address_counter % 256) + ');\n')
    
    def write_screen(self, screen):
        self.sketch.write('  // ' + '#'*20  + screen + '#'*20  +  '\n')
        self.sketch.write('  Wire.write(' + str(len(screen)) + ');\n')
        self.increment_address()
        self.check_page_break()
        for letter in reversed(screen):
            self.sketch.write('  //' + '-'*10 + letter + '-'*10 +  '\n')
            for character in characters[letter]:
                self.sketch.write('  Wire.write(' + character + ');\n')
                self.increment_address()
                self.check_page_break()