Hi,
I am developing an embedded system interfaced trough a web server. I have an Arduino Mega 2560 and a WIZnet5100 ethernet shield. Currently I am powering an 16x2 LCD, DS1307 RTC, 16digit keypad and one IR sensor (E18-D80NK). My html is on a 4GB SD card, its only minimal code to display 4 variables, no css currently, only some javascript and xml.
When I upload my sketch, the bootloader confirms a successful upload of a sketch size: 30,658 bytes
However, the setup does not complete since I have no response from my LCD nor the serial monitor
When I uncomment the web server code and ethernet libraries, the application runs successfully.
I have measured the SRAM with the following function:
int freeRam ()
{
extern int __heap_start, *__brkval;
int v;
return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval);
}
And have called the function in numerous places in the code, the result is as follows:
With the ethernet shield libraries and web server code activated: no response since setup does not complete.
With the libraries and web server code deactivated: 6900 -7000 (bytes I assume)
With the ethernet shield libraries and web server code activated but with a different code structure, one using more while loops, less functions and variables. ( not sufficient for any purpose ): 5500-5600 bytes
I am terribly afraid that I am out of memory, I still need to add 5 IR sensors, 10 variables, 5 functions, 3 Web pages (on the SD-card)
I would love some advice since I am not an experienced developer, programmer, electronics major.
I will attach my code for reference. I have tried reducing the global variables, using the F() function on strings, reducing some datatypes to bytes...
Please assist where possible,
Thank you in advance.
#include <LiquidCrystal.h>
#include <Keypad.h>
#include <Wire.h>
#include "RTClib.h"
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
#define REQ_BUF_SZ 60
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(169, 254, 84, 200);
IPAddress subnet(255, 255, 0, 0);
EthernetServer server(80); // create a server at port 80
File webFile;
char HTTP_req[REQ_BUF_SZ] = {0}; // buffered HTTP request stored as null terminated string
char req_index = 0; // index into HTTP_req buffer
LiquidCrystal lcd(38, 36, 34, 32, 30, 28);
RTC_DS1307 RTC;
const byte numRows = 4;
const byte numCols = 4;
char keymap[numRows][numCols]=
{
{'1', '2', '3', 'A'},
{'4', '5', '6', 'B'},
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}
};
byte rowPins[numRows] = {35, 33, 31, 29};
byte colPins[numCols] = {43, 41, 39, 37};
Keypad keypad = Keypad( makeKeymap(keymap), rowPins, colPins, numRows, numCols );
const int IR1 = 26;
byte SavedNew = 0;
int SavedOld = 0;
int SavedAcc = 0;
char inData[4];
byte index;
byte amount;
int WIP;
char key = keypad.getKey();
boolean TxtConValue = false;
boolean ArrivalValue = true;
boolean started = false;
boolean ended = false;
boolean lastState = 0;
void setup()
{
Wire.begin();
RTC.begin();
server.begin();
Ethernet.begin(mac, ip, subnet);
Wire.begin();
RTC.begin();
Serial.println(freeRam());
Serial.begin(9600);
// initialize SD card
Serial.println(F("Initializing SD card..."));
if (!SD.begin(4)) {
Serial.println(F("*ERROR - SD card initialization failed!"));
return; // init failed
}
Serial.println(F("SUCCESS - SD card initialized."));
// check for file
if (!SD.exists("KPDLCD.htm")) {
Serial.println(F("ERROR - Can't find KPDLCD.htm file!"));
return; // can't find file
}
Serial.println(F("SUCCESS - Found KPDLCD.htm file."));
pinMode(IR1,INPUT_PULLUP);
// disable Ethernet chip
pinMode(10, OUTPUT);
digitalWrite(10, HIGH);
lcd.begin(16,2);
lcd.noAutoscroll();
lcd.print("Arrival Amount:");
lcd.setCursor(0,1);
lcd.print("Enter->");
Serial.println(F("Enter Arrival Amount"));
keypad.setDebounceTime(25);
if (! RTC.isrunning()) {
Serial.println(F("RTC is NOT running!"));
// following line sets the RTC to the date & time this sketch was compiled
//RTC.adjust(DateTime(__DATE__, __TIME__));
}
}
//Save Arrival Amount
int ArrivalAmount()
{
if(ArrivalValue == true)
{
char key = keypad.getKey();
if (key != NO_KEY)
{
lcd.print(key);
if(started == false && key != '*')
{
TxtArrivalAmount();
key = 0;
}
else
{
if (key == '*')
{
started = true;
index = 0 ;
inData[index] = '\0';
}
else if(key == 'A')
{
TxtArrivalAmount();
key = 0;
}
else if(key == '#')
{
ended = true;
}
else if(started)
{
inData[index] = key;
index++;
inData[index] = '\0';
}
}
if(started && ended)
{
amount = atoi(inData);
Serial.print(amount);
started = false;
ended = false;
index = 0;
inData[index] = '\0';
TxtConValue = true;
}
}
return amount;
}
}
//Save Accumulated Amount
void AccumulatedAmount()
{
SavedAcc = SavedNew + SavedOld ;
SavedOld = SavedAcc ;
}
//TextDisplay - Confrim Amount
void TxtConfirmAmount()
{
if(TxtConValue == true )
{
SavedNew = ArrivalAmount();
lcd.clear();
lcd.print("Confirm Input");
lcd.setCursor(0,1);
lcd.print("Amount = ");
lcd.print(SavedNew);
Serial.println();
Serial.println(F("Awaiting Confirmation"));
TxtConValue = false;
ArrivalValue = false;
key = 0;
}
else
ConfirmValue();
}
void ConfirmValue()
{
if(ArrivalValue == false)
{
DateTime now = RTC.now();
key = keypad.getKey();
if(key == 'D')
{
AccumulatedAmount();
Serial.print(F("Value Confirmed: "));
Serial.println(SavedNew);
Serial.print(F("Accumulated Value: "));
Serial.println(SavedAcc);
//Print Time
Serial.print(now.year(), DEC);
Serial.print('/');
Serial.print(now.month(), DEC);
Serial.print('/');
Serial.print(now.day(), DEC);
Serial.print(' ');
Serial.print(now.hour(), DEC);
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.print(now.second(), DEC);
Serial.println();
key = 0;
ArrivalValue = true;
TxtArrivalAmount();
return;
}
else if (key == 'A')
{
ArrivalValue = true;
SavedNew = 0;
key = 0;
TxtArrivalAmount();
return;
}
}
}
//TextDisplay - Arrival Amount
void TxtArrivalAmount()
{
lcd.clear();
lcd.print("Arrival Amount:");
lcd.setCursor(0,1);
lcd.print("Enter->");
lcd.setCursor(7,1);
Serial.println("Enter Arrival Amount");
}
void GetWIP()
{
if(digitalRead(IR1) == 0 && lastState == 0)
{
if(SavedAcc > 0)
{
WIP = --SavedAcc;
Serial.print("object detected");
Serial.print("WIP: ");
Serial.println(WIP);
lastState = 1;
}
else
{
WIP = 0 ;
Serial.print(F("object detected"));
Serial.print("WIP: ");
Serial.println(WIP);
lastState = 1;
}
}
else if(digitalRead(IR1) == 0 && lastState == 1)
{}
else if(digitalRead(IR1) == 1 && lastState == 1)
{
lastState = 0;
}
}
void loop()
{
EthernetClient client = server.available(); // try to get client
if (client) { // got client?
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) { // client data available to read
char c = client.read(); // read 1 byte (character) from client
// buffer first part of HTTP request in HTTP_req array (string)
// leave last element in array as 0 to null terminate string (REQ_BUF_SZ - 1)
if (req_index < (REQ_BUF_SZ - 1)) {
HTTP_req[req_index] = c; // save HTTP request character
req_index++;
}
// last line of client request is blank and ends with \n
// respond to client only after last line received
if (c == '\n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
// remainder of header follows below, depending on if
// web page or XML page is requested
// Ajax request - send XML file
if (StrContains(HTTP_req, "ajax_inputs")) {
// send rest of HTTP header
client.println("Content-Type: text/xml");
client.println("Connection: keep-alive");
client.println();
// send XML file containing input states
XML_response(client);
}
else { // web page request
// send rest of HTTP header
client.println("Content-Type: text/html");
client.println("Connection: keep-alive");
client.println();
// send web page
webFile = SD.open("KPDLCD.htm"); // open web page file
if (webFile) {
while(webFile.available()) {
client.write(webFile.read()); // send web page to client
}
webFile.close();
}
}
// display received HTTP request on serial port
Serial.print(HTTP_req);
// reset buffer index and all buffer elements to 0
req_index = 0;
StrClear(HTTP_req, REQ_BUF_SZ);
break;
}
// every line of text received from the client ends with \r\n
if (c == '\n') {
// last character on line of received text
// starting new line with next character read
currentLineIsBlank = true;
}
else if (c != '\r') {
// a text character was received from client
currentLineIsBlank = false;
}
} // end if (client.available())
} // end while (client.connected())
delay(1); // give the web browser time to receive the data
client.stop(); // close the connection
} // end if (client)
}
// send the XML file with switch statuses and analog value
void XML_response(EthernetClient cl)
{
ArrivalAmount();
TxtConfirmAmount();
GetWIP();
cl.print("<?xml version = \"1.0\" ?>");
cl.print("<inputs>");
cl.print("<Saved>");
cl.print(SavedNew);
cl.println("</Saved>");
cl.print("<Accumulated>");
cl.print(SavedAcc);
cl.println("</Accumulated>");
cl.print("<WIP>");
cl.print(WIP);
cl.println("</WIP>");
DateTime now = RTC.now();
cl.print("<time>");
cl.print(now.year(), DEC);
cl.println("</time>");
cl.print("<time>");
cl.print(now.month(), DEC);
cl.println("</time>");
cl.print("<time>");
cl.print(now.day(), DEC);
cl.println("</time>");
cl.print("<time>");
cl.print(now.hour(), DEC);
cl.println("</time>");
cl.print("<time>");
cl.print(now.minute(), DEC);
cl.println("</time>");
cl.print("<time>");
cl.print(now.second(), DEC);
cl.println("</time>");
cl.print("</inputs>");
}
// sets every element of str to 0 (clears array)
void StrClear(char *str, char length)
{
for (int i = 0; i < length; i++) {
str[i] = 0;
}
}
// searches for the string sfind in the string str
// returns 1 if string found
// returns 0 if string not found
char StrContains(char *str, char *sfind)
{
char found = 0;
char index = 0;
char len;
len = strlen(str);
if (strlen(sfind) > len) {
return 0;
}
while (index < len) {
if (str[index] == sfind[found]) {
found++;
if (strlen(sfind) == found) {
return 1;
}
}
else {
found = 0;
}
index++;
}
return 0;
}