Monday, May 16, 2011

8x8 LED Matrix Scrolling Message Changing In Serial Monitor

The classic scrolling message with the ability to enter a message from the serial monitor and while it is scrolling if you enter a lowercase 'a' in the monitor it stops and you can enter a new message.

To do this I created my own character set (reminds me of the olden days with my Commodore 64 - yes I am that old)

It took 3 evenings to create the character set and then 2 evening to create the code.  So, if you are looking to do something similar the code below with the character set defined may save you some time.


Below is the code.  Be aware I'm more about getting the Arduino to do something and so the code will be a bit rough around the edges.  It works but I definitely do not consider it best practise or even efficent code.
Use at your own risk.

// Control an 8x8 LED display with 2 x 74HC595 shift registers
// Using only 3 pins from the Arduino

// while condition variable
int whileVar = 0;

//Pin connected to Pin 12 of 74HC595 (Latch)
int latchPin = 8;

//Pin connected to Pin 11 of 74HC595 (Clock)
int clockPin = 12;

//Pin connected to Pin 14 of 74HC595 (Data)
int dataPin = 11;

uint8_t led[8];
uint8_t letters[672];
uint8_t currentdisplay[8];

long counter1 = 0;

// Current Character in the charMessage Array
int charMessageCurrent = 0;

// Current line in Letter
int lineLetter = 672;

//currentChar is the current character in the charMessage that is being chekced
char currentChar =32;

// Used to store the message instead of displayMessage
char charMessage[40];

// scrollMessage is array holding the message that will be displayed
uint8_t scrollMessage[480];

// Serial read Byte
int incomingByte = 0;

void setup() {

Serial.begin(9600);
 
// Seed Random Generator with noise from analog pin 0 
randomSeed(analogRead(0));
 
//set pins to output
pinMode(latchPin, OUTPUT);
pinMode(clockPin, OUTPUT);
pinMode(dataPin, OUTPUT);

// Symbol [ ] space
letters[0] =  B00000000;
letters[1] =  B00000000;
letters[2] =  B00000000;
letters[3] =  B00000000;
letters[4] =  B00000000;
letters[5] =  B00000000;
letters[6] =  B00000000;
letters[7] =  B00000000;

// Symbol !
letters[8]  =  B00000000;
letters[9]  =  B00000000;
letters[10] =  B00000000;
letters[11] =  B00000000;
letters[12] =  B11110011;
letters[13] =  B00000000;
letters[14] =  B00000000;
letters[15] =  B00000000;

// Symbol "
letters[16] =  B00000000;
letters[17] =  B00000000;
letters[18] =  B00000000;
letters[19] =  B11100000;
letters[20] =  B00000000;
letters[21] =  B11100000;
letters[22] =  B00000000;
letters[23] =  B00000000;

// Symbol #
letters[24] =  B00000000;
letters[25] =  B00100100;
letters[26] =  B11111111;
letters[27] =  B00100100;
letters[28] =  B00100100;
letters[29] =  B00100100;
letters[30] =  B11111111;
letters[31] =  B00100100;

// Symbol $
letters[32] =  B00000000;
letters[33] =  B01001110;
letters[34] =  B10010001;
letters[35] =  B10010001;
letters[36] =  B11111111;
letters[37] =  B10010001;
letters[38] =  B10010001;
letters[39] =  B01100110;

// Symbol %
letters[40] =  B00000000;
letters[41] =  B10000111;
letters[42] =  B01000101;
letters[43] =  B00110111;
letters[44] =  B00011000;
letters[45] =  B11100100;
letters[46] =  B10000010;
letters[47] =  B11100001;

// Symbol &
letters[48] =  B00000000;
letters[49] =  B01100000;
letters[50] =  B10010101;
letters[51] =  B10010011;
letters[52] =  B10010101;
letters[53] =  B10011001;
letters[54] =  B01011001;
letters[55] =  B00111110;

// Symbol '
letters[56] =  B00000000;
letters[57] =  B00000000;
letters[58] =  B00000000;
letters[59] =  B11100000;
letters[60] =  B00000000;
letters[61] =  B00000000;
letters[62] =  B00000000;
letters[63] =  B00000000;

// Symbol (
letters[64] =  B00000000;
letters[65] =  B00000000;
letters[66] =  B10000001;
letters[67] =  B01000010;
letters[68] =  B00100100;
letters[69] =  B00011000;
letters[70] =  B00000000;
letters[71] =  B00000000;

// Symbol )
letters[72] =  B00000000;
letters[73] =  B00000000;
letters[74] =  B00011000;
letters[75] =  B00100100;
letters[76] =  B01000010;
letters[77] =  B10000001;
letters[78] =  B00000000;
letters[79] =  B00000000;

// Symbol *
letters[80] =  B00000000;
letters[81] =  B10010010;
letters[82] =  B01010100;
letters[83] =  B00111000;
letters[84] =  B11111111;
letters[85] =  B00111000;
letters[86] =  B01010100;
letters[87] =  B10010010;

// Symbol +
letters[88] =  B00000000;
letters[89] =  B00010000;
letters[90] =  B00010000;
letters[91] =  B00010000;
letters[92] =  B11111111;
letters[93] =  B00010000;
letters[94] =  B00010000;
letters[95] =  B00010000;

// Symbol ,
letters[96]  =  B00000000;
letters[97]  =  B00000000;
letters[98]  =  B00000000;
letters[99]  =  B00000110;
letters[100] =  B00000001;
letters[101] =  B00000000;
letters[102] =  B00000000;
letters[103] =  B00000000;

// Symbol -
letters[104] =  B00000000;
letters[105] =  B00000000;
letters[106] =  B00000000;
letters[107] =  B00010000;
letters[108] =  B00010000;
letters[109] =  B00010000;
letters[110] =  B00000000;
letters[111] =  B00000000;

// Symbol .
letters[112] =  B00000000;
letters[113] =  B00000000;
letters[114] =  B00000000;
letters[115] =  B00000011;
letters[116] =  B00000011;
letters[117] =  B00000000;
letters[118] =  B00000000;
letters[119] =  B00000000;

// Symbol /
letters[120] =  B00000000;
letters[121] =  B10000000;
letters[122] =  B01000000;
letters[123] =  B00100000;
letters[123] =  B00011000;
letters[125] =  B00000100;
letters[126] =  B00000010;
letters[127] =  B00000001;

// Number 0 - zero
letters[128] =  B00000000;
letters[129] =  B00111100;
letters[130] =  B01000010;
letters[131] =  B10100001;
letters[132] =  B10010001;
letters[133] =  B10001001;
letters[134] =  B01000010;
letters[135] =  B00111100;

// Number 1
letters[136] =  B00000000;
letters[137] =  B00000000;
letters[138] =  B00000001;
letters[139] =  B11111111;
letters[140] =  B01000001;
letters[141] =  B00100001;
letters[142] =  B00000000;
letters[143] =  B00000000;

// Number 2
letters[144] =  B00000000;
letters[145] =  B01100001;
letters[146] =  B10010001;
letters[147] =  B10001001;
letters[148] =  B10001001;
letters[149] =  B10000101;
letters[150] =  B10000011;
letters[141] =  B01100001;

// Number 3
letters[152] =  B00000000;
letters[153] =  B01111110;
letters[154] =  B10011001;
letters[155] =  B10011001;
letters[156] =  B10011001;
letters[157] =  B10000001;
letters[158] =  B10000001;
letters[159] =  B01000110;

// Number 4
letters[160] =  B00000000;
letters[161] =  B00000100;
letters[162] =  B11111111;
letters[163] =  B01000100;
letters[164] =  B00100100;
letters[165] =  B00010100;
letters[166] =  B00001100;
letters[167] =  B00000100;

// Number 5
letters[168] =  B00000000;
letters[169] =  B10001110;
letters[170] =  B10010001;
letters[171] =  B10010001;
letters[172] =  B10010001;
letters[173] =  B10010001;
letters[174] =  B10010001;
letters[175] =  B11100010;

// Number 6
letters[176] =  B00000000;
letters[177] =  B01001110;
letters[178] =  B10010001;
letters[179] =  B10010001;
letters[180] =  B10010001;
letters[181] =  B10010001;
letters[182] =  B10010001;
letters[183] =  B01111110;

// Number 7
letters[184] =  B00000000;
letters[185] =  B11100000;
letters[186] =  B10010000;
letters[187] =  B10001000;
letters[188] =  B10000111;
letters[189] =  B00000000;
letters[190] =  B00000000;
letters[191] =  B00000000;

// Number 8
letters[192] =  B00000000;
letters[193] =  B01100110;
letters[194] =  B10011001;
letters[195] =  B10011001;
letters[196] =  B10011001;
letters[197] =  B10011001;
letters[198] =  B10011001;
letters[199] =  B01100110;

// Number 9
letters[200] =  B00000000;
letters[201] =  B01111110;
letters[202] =  B10001001;
letters[203] =  B10001001;
letters[204] =  B10001001;
letters[205] =  B10001001;
letters[206] =  B10001001;
letters[207] =  B01110010;

// Symbol :
letters[208] =  B00000000;
letters[209] =  B00000000;
letters[210] =  B00000000;
letters[211] =  B00000000;
letters[212] =  B01100110;
letters[213] =  B00000000;
letters[214] =  B00000000;
letters[215] =  B00000000;

// Symbol ;
letters[216] =  B00000000;
letters[217] =  B00000000;
letters[218] =  B00000000;
letters[219] =  B00000000;
letters[220] =  B01100110;
letters[221] =  B00000001;
letters[222] =  B00000000;
letters[223] =  B00000000;

// Symbol <
letters[224] =  B00000000;
letters[225] =  B00000000;
letters[226] =  B00000000;
letters[227] =  B10000010;
letters[228] =  B01000100;
letters[229] =  B00101000;
letters[230] =  B00010000;
letters[231] =  B00000000;

// Symbol =
letters[232] =  B00000000;
letters[233] =  B00000000;
letters[234] =  B00000000;
letters[235] =  B00100100;
letters[236] =  B00100100;
letters[237] =  B00100100;
letters[238] =  B00100100;
letters[239] =  B00000000;

// Symbol >
letters[240] =  B00000000;
letters[241] =  B00000000;
letters[242] =  B00010000;
letters[243] =  B00101000;
letters[244] =  B01000100;
letters[245] =  B10000010;
letters[246] =  B00000000;
letters[247] =  B00000000;

// Symbol ?
letters[248] =  B00000000;
letters[249] =  B00000000;
letters[250] =  B01100000;
letters[251] =  B10010000;
letters[252] =  B10001101;
letters[253] =  B10000000;
letters[254] =  B01100000;
letters[255] =  B00000000;

// Symbol @
letters[256] =  B00000000;
letters[257] =  B01111000;
letters[258] =  B10100101;
letters[259] =  B10100101;
letters[260] =  B10100101;
letters[261] =  B10011001;
letters[262] =  B10000001;
letters[263] =  B01011110;

// Letter A
letters[264] = B00000000;
letters[265] = B00111111;
letters[266] = B01001000;
letters[267] = B10001000;
letters[268] = B10001000;
letters[269] = B10001000;
letters[270] = B01001000;
letters[271] = B00111111;

// Letter B
letters[272]  = B00000000;
letters[273]  = B01110110;
letters[274] = B10001001;
letters[275] = B10001001;
letters[276] = B10001001;
letters[277] = B10001001;
letters[278] = B10001001;
letters[279] = B11111111;

// Letter C
letters[280] = B00000000;
letters[281] = B00100100;
letters[282] = B01000010;
letters[283] = B10000001;
letters[284] = B10000001;
letters[285] = B10000001;
letters[286] = B01000010;
letters[287] = B00111100;

// Letter D
letters[288] = B00000000;
letters[289] = B00111100;
letters[290] = B01000010;
letters[291] = B10000001;
letters[292] = B10000001;
letters[293] = B10000001;
letters[294] = B10000001;
letters[295] = B11111111;

// Letter E
letters[296] = B00000000;
letters[297] = B10000001;
letters[298] = B10000001;
letters[299] = B10010001;
letters[300] = B10010001;
letters[301] = B10010001;
letters[302] = B10010001;
letters[303] = B11111111;


// Letter F
letters[304] = B00000000;
letters[305] = B10000000;
letters[306] = B10000000;
letters[307] = B10010000;
letters[308] = B10010000;
letters[309] = B10010000;
letters[310] = B10010000;
letters[311] = B11111111;

// Letter G
letters[312] = B00000000;
letters[313] = B00101100;
letters[314] = B01001010;
letters[315] = B10001001;
letters[316] = B10000001;
letters[317] = B10000001;
letters[318] = B01000010;
letters[319] = B00111100;

// Letter H
letters[320] = B00000000;
letters[321] = B11111111;
letters[322] = B00001000;
letters[323] = B00001000;
letters[324] = B00001000;
letters[325] = B00001000;
letters[326] = B00001000;
letters[327] = B11111111;

// Letter I
letters[328] = B00000000;
letters[329] = B00000000;
letters[330] = B10000001;
letters[331] = B10000001;
letters[332] = B11111111;
letters[333] = B10000001;
letters[334] = B10000001;
letters[335] = B00000000;

// Letter J
letters[336] = B00000000;
letters[337] = B10000000;
letters[338] = B10000000;
letters[339] = B11111100;
letters[340] = B10000010;
letters[341] = B10000001;
letters[342] = B10000001;
letters[343] = B10000010;

// Letter K
letters[344] = B00000000;
letters[345] = B10000001;
letters[346] = B01000010;
letters[347] = B00100100;
letters[348] = B00011000;
letters[349] = B00001000;
letters[350] = B00000100;
letters[351] = B11111111;

// Letter L
letters[352] = B00000000;
letters[353] = B00000001;
letters[354] = B00000001;
letters[355] = B00000001;
letters[356] = B00000001;
letters[357] = B00000001;
letters[358] = B00000001;
letters[359] = B11111111;

// Letter M
letters[360] =  B00000000;
letters[361] =  B01111111;
letters[362] =  B10000000;
letters[363] =  B10000000;
letters[364] = B01110000;
letters[365] = B10000000;
letters[366] = B10000000;
letters[367] = B01111111;

// Letter N
letters[368] =  B00000000;
letters[369] =  B11111111;
letters[370] =  B00000010;
letters[371] =  B00000100;
letters[372] =  B00011000;
letters[373] =  B00100000;
letters[374] =  B01000000;
letters[375] =  B11111111;

// Letter 0
letters[376] =  B00000000;
letters[377] =  B00111100;
letters[378] =  B01000010;
letters[379] =  B10000001;
letters[380] =  B10000001;
letters[381] =  B10000001;
letters[382] =  B01000010;
letters[383] =  B00111100;

// Letter P
letters[384] =  B00000000;
letters[385] =  B00110000;
letters[386] =  B01001000;
letters[387] =  B10000100;
letters[388] =  B10000100;
letters[389] =  B10000100;
letters[390] =  B10000100;
letters[391] =  B11111111;

// Letter Q
letters[392] =  B00000000;
letters[393] =  B00111101;
letters[394] =  B01000010;
letters[395] =  B10000101;
letters[396] =  B10001001;
letters[397] =  B10000001;
letters[398] =  B01000010;
letters[399] =  B00111100;

// Letter R
letters[400] =  B00000000;
letters[401] =  B00110001;
letters[402] =  B01001010;
letters[403] =  B10000100;
letters[404] =  B10000100;
letters[405] =  B10000100;
letters[406] =  B10000100;
letters[407] =  B11111111;

// Letter S
letters[408] =  B00000000;
letters[409] =  B01001110;
letters[410] =  B10010001;
letters[411] =  B10010001;
letters[412] =  B10010001;
letters[413] =  B10010001;
letters[414] =  B10010001;
letters[415] =  B01100110;

// Letter T
letters[416] =  B00000000;
letters[417] =  B10000000;
letters[418] =  B10000000;
letters[419] =  B10000000;
letters[420] =  B11111111;
letters[421] =  B10000000;
letters[422] =  B10000000;
letters[423] =  B10000000;

// Letter U
letters[424] =  B00000000;
letters[425] =  B11111100;
letters[426] =  B00000010;
letters[427] =  B00000001;
letters[428] =  B00000001;
letters[429] =  B00000001;
letters[430] =  B00000010;
letters[431] =  B11111100;

// Letter V
letters[432] =  B00000000;
letters[433] =  B11111000;
letters[434] =  B00000100;
letters[435] =  B00000010;
letters[436] =  B00000001;
letters[437] =  B00000010;
letters[438] =  B00000100;
letters[439] =  B11111000;

// Letter W
letters[440] =  B00000000;
letters[441] =  B11111110;
letters[442] =  B00000001;
letters[443] =  B00000001;
letters[444] =  B00001110;
letters[445] =  B00000001;
letters[446] =  B00000001;
letters[447] =  B11111110;

// Letter X
letters[448] =  B00000000;
letters[449] =  B10000001;
letters[450] =  B01000010;
letters[451] =  B00100100;
letters[452] =  B00011000;
letters[453] =  B00100100;
letters[454] =  B01000010;
letters[455] =  B10000001;

// Letter Y
letters[456] =  B00000000;
letters[457] =  B10000000;
letters[458] =  B01000000;
letters[459] =  B00100000;
letters[460] =  B00011111;
letters[461] =  B00100000;
letters[462] =  B01000000;
letters[463] =  B10000000;

// Letter Z
letters[464] =  B00000000;
letters[465] =  B10000001;
letters[466] =  B11000001;
letters[467] =  B10100001;
letters[468] =  B10010001;
letters[469] =  B10001001;
letters[470] =  B10000101;
letters[471] =  B10000011;

// Symbol !
letters[472] =  B00000000;
letters[473] =  B00000000;
letters[474] =  B00000000;
letters[475] =  B00000000;
letters[476] =  B11110011;
letters[477] =  B00000000;
letters[478] =  B00000000;
letters[479] =  B00000000;

// Symbol "
letters[480] =  B00000000;
letters[481] =  B00000000;
letters[482] =  B00000000;
letters[483] =  B11100000;
letters[484] =  B00000000;
letters[485] =  B11100000;
letters[486] =  B00000000;
letters[487] =  B00000000;

// Symbol #
letters[488] =  B00000000;
letters[489] =  B00100100;
letters[490] =  B11111111;
letters[491] =  B00100100;
letters[492] =  B00100100;
letters[493] =  B00100100;
letters[494] =  B11111111;
letters[495] =  B00100100;

// Symbol $
letters[496] =  B00000000;
letters[497] =  B01001110;
letters[498] =  B10010001;
letters[499] =  B10010001;
letters[500] =  B11111111;
letters[501] =  B10010001;
letters[502] =  B10010001;
letters[503] =  B01100110;

// Symbol %
letters[504] =  B00000000;
letters[505] =  B00000000;
letters[506] =  B01000110;
letters[507] =  B00110000;
letters[508] =  B00011000;
letters[509] =  B00000100;
letters[510] =  B01100010;
letters[511] =  B00000001;

// Symbol &
letters[512] =  B00000000;
letters[513] =  B00000000;
letters[514] =  B00000101;
letters[515] =  B01000010;
letters[516] =  B10100101;
letters[517] =  B10101001;
letters[518] =  B01010001;
letters[519] =  B00101110;

// Symbol '
letters[520] =  B00000000;
letters[521] =  B00000000;
letters[522] =  B00000000;
letters[523] =  B11100000;
letters[524] =  B00000000;
letters[525] =  B00000000;
letters[526] =  B00000000;
letters[527] =  B00000000;

// Symbol (
letters[528] =  B00000000;
letters[529] =  B00000000;
letters[530] =  B10000001;
letters[531] =  B01000010;
letters[532] =  B00100100;
letters[533] =  B00011000;
letters[534] =  B00000000;
letters[535] =  B00000000;

// Symbol )
letters[536] =  B00000000;
letters[537] =  B00000000;
letters[538] =  B00011000;
letters[539] =  B00100100;
letters[540] =  B01000010;
letters[541] =  B10000001;
letters[542] =  B00000000;
letters[543] =  B00000000;

// Symbol *
letters[544] =  B00000000;
letters[545] =  B10010010;
letters[546] =  B01010100;
letters[547] =  B00111000;
letters[548] =  B11111111;
letters[549] =  B00111000;
letters[550] =  B01010100;
letters[551] =  B10010010;

// Symbol +
letters[552] =  B00000000;
letters[553] =  B00010000;
letters[554] =  B00010000;
letters[555] =  B00010000;
letters[556] =  B11111111;
letters[557] =  B00010000;
letters[558] =  B00010000;
letters[559] =  B00010000;

// Symbol '
letters[560] =  B00000000;
letters[561] =  B00000000;
letters[562] =  B00000000;
letters[563] =  B11000000;
letters[564] =  B00100000;
letters[565] =  B00000000;
letters[566] =  B00000000;
letters[567] =  B00000000;

// Symbol -
letters[568] =  B00000000;
letters[569] =  B00000000;
letters[570] =  B00000000;
letters[571] =  B00010000;
letters[572] =  B00010000;
letters[573] =  B00010000;
letters[574] =  B00000000;
letters[575] =  B00000000;

// Symbol .
letters[576] =  B00000000;
letters[577] =  B00000000;
letters[578] =  B00000000;
letters[579] =  B00000011;
letters[580] =  B00000011;
letters[581] =  B00000000;
letters[582] =  B00000000;
letters[583] =  B00000000;

// Symbol /
letters[584] =  B00000000;
letters[585] =  B10000000;
letters[586] =  B01000000;
letters[587] =  B00100000;
letters[588] =  B00011000;
letters[589] =  B00000100;
letters[590] =  B00000010;
letters[591] =  B00000001;

// Number 0 - zero
letters[592] =  B00000000;
letters[593] =  B00111100;
letters[594] =  B01000010;
letters[595] =  B10100001;
letters[596] =  B10010001;
letters[597] =  B10001001;
letters[598] =  B01000010;
letters[599] =  B00111100;

// Number 1
letters[600] =  B00000000;
letters[601] =  B00000000;
letters[602] =  B00000001;
letters[603] =  B11111111;
letters[604] =  B01000001;
letters[605] =  B00100001;
letters[606] =  B00000000;
letters[607] =  B00000000;

// Number 2
letters[608] =  B00000000;
letters[609] =  B01100001;
letters[610] =  B10010001;
letters[611] =  B10001001;
letters[612] =  B10001001;
letters[613] =  B10000101;
letters[614] =  B10000011;
letters[615] =  B01100001;

// Number 3
letters[616] =  B00000000;
letters[617] =  B01111110;
letters[618] =  B10011001;
letters[619] =  B10011001;
letters[620] =  B10011001;
letters[621] =  B10000001;
letters[622] =  B10000001;
letters[623] =  B01000110;

// Number 4
letters[624] =  B00000000;
letters[625] =  B00000100;
letters[626] =  B11111111;
letters[627] =  B01000100;
letters[628] =  B00100100;
letters[629] =  B00010100;
letters[630] =  B00001100;
letters[631] =  B00000100;

// Number 5
letters[632] =  B00000000;
letters[633] =  B10001110;
letters[634] =  B10010001;
letters[635] =  B10010001;
letters[636] =  B10010001;
letters[637] =  B10010001;
letters[638] =  B10010001;
letters[639] =  B11100010;

// Number 6
letters[640] =  B00000000;
letters[641] =  B01001110;
letters[642] =  B10010001;
letters[643] =  B10010001;
letters[644] =  B10010001;
letters[645] =  B10010001;
letters[646] =  B10010001;
letters[647] =  B01111110;

// Number 7
letters[648] =  B00000000;
letters[649] =  B11100000;
letters[650] =  B10010000;
letters[651] =  B10001000;
letters[652] =  B10000111;
letters[653] =  B00000000;
letters[654] =  B00000000;
letters[655] =  B00000000;

// Number 8
letters[656] =  B00000000;
letters[657] =  B01100110;
letters[658] =  B10011001;
letters[659] =  B10011001;
letters[660] =  B10011001;
letters[661] =  B10011001;
letters[662] =  B10011001;
letters[663] =  B01100110;

// Number 9
letters[664] =  B00000000;
letters[665] =  B01111110;
letters[666] =  B10001001;
letters[667] =  B10001001;
letters[668] =  B10001001;
letters[669] =  B10001001;
letters[670] =  B10001001;
letters[671] =  B01110010;


for (int i = 0; i < 8; i++){
  led[i] = letters[i];
  currentdisplay[i] = letters[i];
  }
}

void loop() {

// Clear the screen before starting
for (int i=448; i <456; i++){
  led[i-448] = letters[i];
  currentdisplay[i-448] = letters[i];;
}
screenUpdate();

// Reseting variables
whileVar = 0;
counter1 = 0;
charMessageCurrent = 0;
lineLetter = 672;
currentChar =32;

//  Start Reading the Serial Data

while (whileVar ==0){
screenUpdate();
 
// send data only when you receive data:
    if (Serial.available() > 0) {
        // read the incoming byte:
        incomingByte = Serial.read();

                // If the byte read is an 'a' stop, otherwise add the byte to the string
                if (incomingByte ==97){
                whileVar =1;
                }
                else
                {
                charMessage[charMessageCurrent] = incomingByte;
                charMessageCurrent++;
                } 
        }
}

// End Reading Serial Data 
 

// prints charMessage
Serial.write("charMessage is: ");

for (int i=0; i<charMessageCurrent; i++){
Serial.write(charMessage[i]);
}
Serial.println("");

// Making the first 8 Bytes - character a space
for(int i =0; i <8; i++){
  scrollMessage[i] = B00000000;
}
// Move counter1 to 8 so that the space stays in place
counter1=8; 
 
for (int i=0; i < charMessageCurrent; i++){
currentChar = charMessage[i];

for (int x=7; x >= 0; x--){
  scrollMessage[counter1] = letters[((currentChar-32)*8)+x];
  counter1++;
  }
}
// End Sorting out the message for scrolling

// Clear the screen before starting
for (int i=0; i <8 ; i++){
  led[i] = B00000000;
  currentdisplay[i] = B00000000;;
}
screenUpdate();

// Reseting current1 to 0 as it is used for the delay in the code below
counter1=0;

// Resetting whileVar so it can be used again
whileVar=0;

while (whileVar ==0)
{
// Check if I enter just an a - lower case a to exit the system
    if (Serial.available() > 0) {
        // read the incoming byte:
        incomingByte = Serial.read();

                // If the byte read is an 'a' stop, otherwise add the byte to the string
                if (incomingByte ==97){
                whileVar =1;
                }
        }  
// counter1 used for delay in animation
counter1++;

// set the LEDs
screenUpdate();

// Loop for the action - counter1 used for the delay in scrolling
if (counter1 >= 25) {
counter1 = 0;
lineLetter++;

if (lineLetter >(((charMessageCurrent)*8)+7)){
  lineLetter = 0;
  }
// Do scrolling

for (int i = 8; i > 0; i--){
  led[i] = currentdisplay[i-1];
  }
led[0] = scrollMessage[lineLetter];

for (int i=0; i <8; i++){
  currentdisplay[i] = led[i];
  }

}

}

}

void screenUpdate() {
uint8_t row = B00000001;

for (byte k = 0; k < 9; k++) {
// Open up the latch ready to receive data
digitalWrite(latchPin, LOW);
shiftIt(~row );
shiftIt(led[k] ); // LED array

// Close the latch, sending the data in the registers out to the matrix
digitalWrite(latchPin, HIGH);
row = row << 1;
  }
}

void shiftIt(byte dataOut) {
// Shift out 8 bits LSB first,
// on rising edge of clock

boolean pinState;

//clear shift register read for sending data
digitalWrite(dataPin, LOW);

// for each bit in dataOut send out a bit
for (int i=0; i<8; i++) {

  //set clockPin to LOW prior to sending bit
digitalWrite(clockPin, LOW);

// if the value of DataOut and (logical AND) a bitmask
// are true, set pinState to 1 (HIGH)
if ( dataOut & (1<<i) ) {
pinState = HIGH;
}
else {
  pinState = LOW;
}

//sets dataPin to HIGH or LOW depending on pinState
digitalWrite(dataPin, pinState);

//send bit out on rising edge of clock
digitalWrite(clockPin, HIGH);
digitalWrite(dataPin, LOW);
}

//stop shifting
digitalWrite(clockPin, LOW);
}