Sender - I/O

-- Sender by CFG

local sendSide = "back"
local clockSide = "right"
local parityBit = 0
local counter = 0

local filename = "text"

local maxw, maxh = term.getSize()

local function splitByChunk(text, chunkSize)
    local s = {}
    for i=1, #text, chunkSize do
        s[#s+1] = text:sub(i,i+chunkSize - 1)
    end
    return s
end

function string.tohex(str)
    return (str:gsub('.', function (c)
        return string.format('%02X', string.byte(c))
    end))
end

function hex2bin(str)
    local map = {
        ["0"]="0000",
        ["1"]="0001",
        ["2"]="0010",
        ["3"]="0011",
        ["4"]="0100",
        ["5"]="0101",
        ["6"]="0110",
        ["7"]="0111",
        ["8"]="1000",
        ["9"]="1001",
        ["a"]="1010",
        ["b"]="1011",
        ["c"]="1100",
        ["d"]="1101",
        ["e"]="1110",
        ["f"]="1111",
        ["A"]="1010",
        ["B"]="1011",
        ["C"]="1100",
        ["D"]="1101",
        ["E"]="1110",
        ["F"]="1111",
    }
    return str:gsub('[0-9A-F]', map)
end

if fs.exists(filename) == true then
        h = fs.open(filename, "r")
        text = h.readAll()
        h.close()
        strHex = string.tohex(text)
        strBin = hex2bin(strHex)

    else
        print("file does not exist, check path..")
    end


local function error(errore)
    term.clear()
    term.setCursorPos(1, 1)
    term.write("Error!!!!!")
    term.setCursorPos((maxw - #errore) / 2, 6)
    term.write(errore)
    os.sleep(5)
    os.reboot()
end

local function toBinary(num)
    return hexToBin_lut[num]
end

local function sendStartSequence()
    -- Start of TEXT: 10
    rs.setOutput(clockSide, true)
    rs.setOutput(sendSide, true)
    os.sleep(0.2)
    rs.setOutput(clockSide, false)
    rs.setOutput(sendSide, false)

end

local function sendStopSequence()
    -- End of TEXT: 11
    rs.setOutput(sendSide, false)

    rs.setOutput(clockSide, true)
    os.sleep(0.2)
    rs.setOutput(clockSide, false)
    if parityBit % 2 == 0 then
        rs.setOutput(sendSide, true)
        os.sleep(0.2)
        rs.setOutput(sendSide, false)
    end

end

term.clear()
term.setCursorPos(1,1)
print("Calafrica Group -- Calaofeng UV5R+Plus\n\n")
print("Bin to send..".. strBin)


while true do
    os.sleep(0.1)
    sendStartSequence()
    os.sleep(0.2)

    -- Qui in poi legge il file
    for i = 1, #strBin do
        local c = strBin:sub(i,i)
        if c == "1" then
            rs.setOutput(sendSide, true)
            parityBit = parityBit + 1
        else
            rs.setOutput(sendSide, false)
        end
        os.sleep(0.2)
    end
    -- Finisce il file

    sendStopSequence()
    parityBit = 0
    os.sleep(1)


end