Hi guys,
I am currently working on an electronic notice board project using the SIM900, Arduino uno and a 32x8 MAX7219 drove LED matrix. I am currently having issues when reading in more than one message. Currently I am reading in a message and it will scroll across the screen once and then freeze. Once I send another message this will do the same and scroll across the screen once and freeze. The message should continuously scroll across the screen until a new one is sent to replace it. I believe that the clearing of the array is messing up the scrolling but I am not sure why. The full code is below:
#include <LedControl.h>
#include "charmap.h"
#include <SoftwareSerial.h>
const int numDevices = 4; // number of MAX7219s used
const long scrollDelay = 75; // adjust scrolling speed
unsigned long bufferLong [14];
const byte numChars = 160;
char receivedChars[numChars];
int inbox = 0;
LedControl lc=LedControl(12,11,10,numDevices); // DOUT|CLK|CS|Devices
SoftwareSerial SIM900(7,8); // RX|TX
//---------------------------------------------------------------------------------------------------------
void setup(){
for (int x=0; x<numDevices; x++){
lc.shutdown(x,false); // the MAX72XX is in power-saving mode on startup
lc.setIntensity(x,8); // set brightness of display
lc.clearDisplay(x); // clear display
}
digitalWrite(9, HIGH); // turns on the shield
delay(1000);
digitalWrite(9, LOW);
delay(5000);
SIM900.begin(19200); // sim900 operates at a baud rate of 19200
Serial.begin(19200); // sets the serial baud rate
delay(10000); // delay for GSM shield to log on
SIM900.print("AT+CMGF=1\r"); // set sim900 to receive sms
delay(100);
SIM900.print("AT+CNMI=2,2,0,0,0\r"); // sms to be sent to serial output
delay(100);
}
void loop(){
scrollMessage();
}
void scrollMessage() {
static boolean recvInProgress = false;
static byte ndx = 0;
char startMarker = '<';
char endMarker = '>';
char rc;
boolean newData = false;
int myChar = 0;
while (SIM900.available() > 0 && newData == false) {
if (inbox == 1){
for(int i =0; i < 160; i++){
receivedChars[i] = (char)0;
}
inbox = 0;
}
rc = SIM900.read();
if (recvInProgress == true) {
if (rc != endMarker) {
receivedChars[ndx] = rc;
ndx++;
if (ndx >= numChars) {
ndx = numChars - 1;
}
}
else {
receivedChars[ndx] = '\0'; // terminate the string
recvInProgress = false;
ndx = 0;
newData = true;
inbox++;
}
}
else if (rc == startMarker) {
recvInProgress = true;
}
}
do {
for (int i = 0; i < 160; i++){
myChar = receivedChars[i];
if (myChar != 0){
loadBufferLong(myChar);
}
}
}
while (myChar != 0);
}
// Load character into scroll buffer
void loadBufferLong(int ascii){
if (ascii >= 0x20 && ascii <=0x7f){
for (int a=0;a<7;a++){ // Loop 7 times for a 5x7 font
unsigned long c = pgm_read_byte_near(font5x7 + ((ascii - 0x20) * 8) + a); // Index into character table to get row data
unsigned long x = bufferLong [a*2]; // Load current scroll buffer
x = x | c; // OR the new character onto end of current
bufferLong [a*2] = x; // Store in buffer
}
byte count = pgm_read_byte_near(font5x7 +((ascii - 0x20) * 8) + 7); // Index into character table for kerning data
for (byte x=0; x<count;x++){ // creates a space between characters
rotateBufferLong();
printBufferLong();
delay(scrollDelay);
}
}
}
// Rotate the buffer
void rotateBufferLong(){
for (int a=0;a<7;a++){ // Loop 7 times for a 5x7 font
unsigned long x = bufferLong [a*2]; // Get low buffer entry
byte b = bitRead(x,31); // Copy high order bit that gets lost in rotation
x = x<<1; // Rotate left one bit
bufferLong [a*2] = x; // Store new low buffer
x = bufferLong [a*2+1]; // Get high buffer entry
x = x<<1; // Rotate left one bit
bitWrite(x,0,b); // Store saved bit
bufferLong [a*2+1] = x; // Store new high buffer
}
}
// Display Buffer on LED matrix
void printBufferLong(){
for (int a=0;a<7;a++){ // Loop 7 times for a 5x7 font
unsigned long x = bufferLong [a*2+1]; // Get high buffer entry
byte y = x; // mask for first character
lc.setRow(3,a,y); // send row to relevent MAX7219 chip
x = bufferLong [a*2]; // Get low buffer entry
y = (x>>24); // mask for second character
lc.setRow(2,a,y);
y = (x>>16); // mask for third character
lc.setRow(1,a,y);
y = (x>>8); // mask for fourth character
lc.setRow(0,a,y);
}
}
