I have a PS2You LED message board that I decided would make a great wall clock/calendar/weather station/etc. and connected it to a Rugged Circuits Yellowjacket. The intent is to update the LED message board over wifi using a simple REST-like interface. After some experimentation, I can get the REST services working over wifi, or I can get the LED message board to update, but I can't seem to do both. This appears to be an issue with the Yellowjacket running out of SRAM while attempting to use both the WiServer library and the DisplayMatrix library at the same time.
I've posted my code below (which could probably be refactored some to decrease the SRAM memory usage) but I suspect that I'm going to need to refactor one or both libraries to get enough free memory to make everything work properly. Can anyone offer any help or suggestions on the best way to approach this? I'm afraid its been a long time since I've had to do any optimization of this type... 
/*
* A simple sketch that uses WiServer to recieve a web call and update the display
*/
// for the wifi:
#include <EEPROM.h>
#include <TinyREST.h>
#include <WiServer.h>
// for the display:
#include <string.h>
#include "MatrixDisplay.h"
#include "DisplayToolbox.h"
#include "font.h"
#define WIRELESS_MODE_INFRA 1
#define WIRELESS_MODE_ADHOC 2
// Wireless configuration parameters ----------------------------------------
unsigned char local_ip[] = {192,168,1,20}; // IP address of WiShield
unsigned char gateway_ip[] = {192,168,1,1}; // router or gateway IP address
unsigned char subnet_mask[] = {255,255,255,0}; // subnet mask for the local network
const prog_char ssid[] PROGMEM = {"TESTSSID"}; // max 32 bytes
unsigned char security_type = 3; // 0 - open; 1 - WEP; 2 - WPA; 3 - WPA2
// WPA/WPA2 passphrase
const prog_char security_passphrase[] PROGMEM = {"testpassphrase"}; // max 64 characters
// WEP 128-bit keys
// sample HEX keys
prog_uchar wep_keys[] PROGMEM = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, // Key 0
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Key 1
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Key 2
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 // Key 3
};
// setup the wireless mode
// infrastructure - connect to AP
// adhoc - connect to another WiFi device
unsigned char wireless_mode = WIRELESS_MODE_INFRA;
unsigned char ssid_len;
unsigned char security_passphrase_len;
// End of wireless configuration parameters ----------------------------------------
// Matrix display configuration parameters ----------------------------------------
const int numLines = 6; // Max number of lines
const int displayTime = 2500; // Length of time in milliseconds to display each line
const int gapTime = 10; // Time gap between lines
const int maxLineLength = 100; // Maximum length of a line in characters
String textLines[numLines]; // Array of text lines
int textLength; // Holds current line length in pixels
int strLength; // Holds current line length in characters
int currentLine = 0; // Index of current line
char defaultText[numLines][30] = {{"Awaiting input..."}};
// Character lookup string -- used to map the characters from the keyboard onto the font data array
// (This should probably be moved to program memory in some form in the future)
String charLookup = " 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*(),-.?></\\|[]_=+:'\"{}";
// Macro to make it the initDisplay function a little easier to understand
#define setMaster(dispNum, CSPin) initDisplay(dispNum,CSPin,true)
#define setSlave(dispNum, CSPin) initDisplay(dispNum,CSPin,false)
// Initialize matrix
//MatrixDisplay disp(3,16,15, true);
//DisplayToolbox toolbox(&disp);
// Prepare boundaries
uint8_t X_MAX = 0;
uint8_t Y_MAX = 0;
#define is_printable(c) (!(c&0x80))
int line = 0;
const unsigned int MAX_INPUT = 100;
// End of matrix display configuration parameters ----------------------------------------
TinyREST rest = TinyREST();
static char cmd_read_string[] = {"string_read"};
static char cmd_write_string[] = {"string_write"};
// This is our page serving function that generates web pages
boolean sendMyPage(char* URL) {
return rest.handleURL(URL);
}
void setup() {
// Initialize WiServer and have it use the sendMyPage function to serve pages
rest.init();
rest.addCommand(cmd_read_string, 2, testCallback);
rest.addCommand(cmd_write_string, 2, testCallback);
WiServer.init(sendMyPage);
// Enable Serial output and ask WiServer to generate log messages (optional)
Serial.begin(57600);
WiServer.enableVerboseMode(true);
// Enable matrix display
// for(int i=0; i<numLines; i++){
// textLines[i] = defaultText[i];
// Serial.println(defaultText[i]);
// }
//
// // Fetch display bounds
// X_MAX = disp.getDisplayCount() * (disp.getDisplayWidth()-1)+3;
// Y_MAX = disp.getDisplayHeight()-1;
//
// // Prepare displays
// disp.setMaster(0,4);
// disp.setSlave(1,5);
// disp.setSlave(2,6);
}
void loop(){
// Run WiServer
WiServer.server_task();
rest.loop();
delay(10);
}
//This is where the lines being displayed on the message board can be updated (or read). To be implemented when memory issues are resolved.
static int testCallback(TinyREST *srv, char *cmd, int len, char **args, void *blind){
if (strcmp(cmd, cmd_read_string)==0) {
//read the string
WiServer.print("<html>");
WiServer.print("***Pretending to read string!");
WiServer.print("</html>");
Serial.println("***Pretending to read string!");
return RESPONSE_INLINE_OK;
} else if (strcmp(cmd, cmd_write_string)==0) {
//write the string
WiServer.print("<html>");
WiServer.print("***Pretending to write string!");
WiServer.print("</html>");
Serial.println("***Pretending to write string!");
return RESPONSE_INLINE_OK;
}
return RESPONSE_OK;
}