str27seg.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
File: str27seg.py
Author: emilio1625
Email: emilio1625@gmail.com
Github: https://github.com/emilio1625
Description: Creates a hex file with the bytes needed to display a string in a
7 segment display. Useful for programming an EEPROM to display text.
"""
from intelhex import IntelHex

char2seg = {
    # got with http://www.uize.com/examples/seven-segment-display.html
    '0': 0x7E,
    '1': 0x30,
    '2': 0x6D,
    '3': 0x79,
    '4': 0x33,
    '5': 0x5B,
    '6': 0x5F,
    '7': 0x70,
    '8': 0x7F,
    '9': 0x7B,
    'a': 0x77,
    'b': 0x1F,
    'c': 0x0D,
    'd': 0x3D,
    'e': 0x4F,
    'f': 0x47,
    'g': 0x5E,
    'h': 0x17,
    'i': 0x10,
    'j': 0x38,
    'k': 0x57,
    'l': 0x0E,
    '*': 0x36,  # placeholder for ll
    '#': 0x34,  # placeholder for il
    '&': 0x16,  # placeholder for li
    'n': 0x15,
    'ñ': 0x55,
    'o': 0x1d,
    'p': 0x67,
    'q': 0x73,
    'r': 0x05,
    's': 0x5B,
    't': 0x0f,
    'u': 0x3E,
    'v': 0x3E,
    'x': 0x37,
    'y': 0x3B,
    'z': 0x6D,
    '-': 0x01,
    '~': 0x01,
    '_': 0x08,
    '=': 0x48,
    '[': 0x4E,
    '(': 0x4E,
    ']': 0x78,
    ')': 0x78,
    "'": 0x20,
    "`": 0x02,
    '°': 0x63,
    '"': 0x22,
    '@': 0x5F,
    '?': 0x65,
    '¿': 0x2D,
    '!': 0xB0,
    '^': 0x62,
    ' ': 0x00,
}


def str27seg(string, address=0, common_cathode=True):
    """Creates a IntelHex object with the bytes needed to display a string in
    a 7 segments display. It suposses the folowing connections.
     bit | segment
      0  |   g
      1  |   f
      2  |   e
      3  |   d
      4  |   c
      5  |   b
      6  |   a
      7  |   dp
    replaces m and w by nn and uu.

    @param string: Cadena a transformar
    @type  string: str

    @return: mem
    @rtype : IntelHex
    """
    # *, #, & are our placeholders, so we delete it from the string
    string = string.replace('*', '').replace('#', '').replace('&', '')
    string = ' '.join(string.split())
    string = string.casefold()
    string = string.replace('11', '*').replace('ll', '*').replace('il', '#')
    string = string.replace('li', '&').replace('m', 'nn').replace('w', 'uu')
    print(string)
    mem = IntelHex()
    for char in string:
        if char in char2seg:
            previous = char
            mem[address] = char2seg[char]
            address += 1
        elif char == '.' or char == ',':
            # Solo ponemos punto si el caracter anterior era representable
            if previous:
                mem[address - 1] &= 0x80
        else:
            previous = 0
    if not common_cathode:
        for i in range(len(mem)):
            mem[i] = ~mem[i]
    return mem


def str2hex(string, filen):
    hexf = str27seg(string)
    hexf.write_hex_file(filen)