hi guy, need help in this programming
got error in the " Wire.send"
#include <Wire.h>
#include <EEPROM.h>
#define MAX_NO_CARDS 102
#define waitingLED 6
#define successLED 7
#define failureLED 5
int toggleState = 0; // state of the toggling LED
long toggleTime = 0; // delay time of the toggling LED
byte tag[4]; // tag serial numbers are 4 bytes long
void setup() {
Wire.begin(); // join i2c bus
Serial.begin(9600); // set up serial port
Wire.beginTransmission(0x42); // the RFID reader's address is 42
Wire.send(0x01); // Length
Wire.send(0x80); // reset reader
Wire.send(0x81); // Checksum
Wire.endTransmission();
// initialize the LEDs:
pinMode(waitingLED, OUTPUT);
pinMode(successLED, OUTPUT);
pinMode(failureLED, OUTPUT);
// print user instructions serially:
Serial.println("n - add card to database");
Serial.println("c - clear entire database");
Serial.println("d - delete card from database");
Serial.println("p - print database");
// delay to allow reader startup time:
delay(2000);
}
void loop() {
if (Serial.available() > 0) {
// read the latest byte:
char incomingByte = Serial.read();
switch (incomingByte) {
case 'n': // if user enters 'n' then store tag number
seekNewTag();
break;
case 'c':
eraseEEPROM(); // if user enters 'c' then erase database
Serial.println("Database deleted");
break;
case 'd': // if user enters 'd' then delete the last tag
seekAndDeleteTag();
break;
case'p': // if user enters 'p' then print the database
printTags();
break;
}
}
else {
//if there's no serial data coming in,
// the default action is to seek new tags:
seekNewTag();
}
// delay before next command to the reader:
delay(200);
}
void eraseEEPROM(){
for(int i = 0; i < 512; i++){
EEPROM.write(i, 0);
}
}
void writeTag(int startingAddress, byte byte0, byte byte1, byte byte2, byte byte3){
EEPROM.write( startingAddress*5, byte(1));
EEPROM.write(startingAddress*5+1, byte0);
EEPROM.write(startingAddress*5+2, byte1);
EEPROM.write(startingAddress*5+3, byte2);
EEPROM.write(startingAddress*5+4, byte3);
}
// delete tag from a specified location
void deleteTag(int startingAddress){
EEPROM.write( startingAddress*5, byte(0));
EEPROM.write(startingAddress*5+1, byte(0));
EEPROM.write(startingAddress*5+2, byte(0));
EEPROM.write(startingAddress*5+3, byte(0));
EEPROM.write(startingAddress*5+4, byte(0));
}
// find the first empty entry in the database:
int findEmptyTag(){
for (int startingAddress = 0; startingAddress< MAX_NO_CARDS; startingAddress++){
byte value = EEPROM.read(startingAddress*5);
if (value == byte(0)) {
return(startingAddress);
}
}
return(200);
}
// print the entire database
void printTags(){
for (int thisTag = 0; thisTag< MAX_NO_CARDS; thisTag++){
printOneTag(thisTag);
}
}
// print a single tag given the tag's address:
void printOneTag(int address) {
Serial.print(address);
Serial.print(":");
for (int offset = 1; offset < 5; offset++) {
int thisByte = int(EEPROM.read(address*5+offset));
// if the byte is less than 16, i.e. only one hex character
// add a leading 0:
if (thisByte < 0x10) {
Serial.print("0");
}
// print the value:
Serial.print(thisByte,HEX);
}
// add a final linefeed and carriage return:
Serial.println();
}
//lookup tag in the database:
int lookupTag(byte byte0, byte byte1, byte byte2, byte byte3){
for (int thisCard = 0; thisCard< MAX_NO_CARDS; thisCard++){
byte value = EEPROM.read(thisCard*5);
if (value != byte(0)){ //it is a valid tag
//see if all four bytes are the same as the ones we're looking for
if(byte0 == EEPROM.read(thisCard*5+1) && byte1 == EEPROM.read(thisCard*5+2)
&& byte2 == EEPROM.read(thisCard*5+3) && byte3 == EEPROM.read(thisCard*5+4)) {
return(thisCard);
}
}
}
// if you don't find the tag, return 200;
return(200);
}
int getTag(){
byte count = 0;
byte valid = 0;
byte byteFromReader = 0;
Wire.beginTransmission(0x42);
Wire.send(0x01); // Length
Wire.send(0x82); // Seek for tags
Wire.send(0x83); // Checksum
Wire.endTransmission();
delay(100);
Wire.requestFrom(0x42, 8); // get data (8 bytes) from reader
count = 0; // keeps track of which byte it is in the response from the reader
valid = 0; // used to indicate that there is a tag there
while(Wire.available()) { // while data is coming from the reader
byteFromReader = Wire.receive();
// no RFID found: reader sends character 2:
if ((count == 0) && (byteFromReader == 2)) {
return(0);
}
if ((count == 0) && (byteFromReader== 6)) {
//if reader sends 6, the tag serial number is coming:
valid = 1;
}
count++;
if ((valid == 1) && (count > 3) && (count < 8)) {
// strip out the header bytes :
tag[count-4] = byteFromReader;
}
// all four bytes received: tag serial number complete:
if ((valid == 1) && (count == 8)) {
return(1);
}
}
}
void seekNewTag() {
Serial.println("Waiting for card");
while(getTag() == 0){
// wait for tag
if (millis() - toggleTime > 1000) {
toggle(waitingLED);
toggleTime = millis();
}
// unless you get a byte of serial data,
if (Serial. available()) {
// break out of the while loop
// and out of the seekNewTag() method:
return;
}
}
// look it up in the database:
int tagToCheck = lookupTag(tag[0], tag[1], tag[2], tag[3]);
if (tagToCheck != 200){
Serial.println("That tag is already stored");
printOneTag(tagToCheck);
}
else {
int emptyTagLocation = findEmptyTag();
if (emptyTagLocation != 200){
writeTag(emptyTagLocation, tag[0], tag[1], tag[2], tag[3]);
Serial.println("That tag is new");
printOneTag(emptyTagLocation);
blink(successLED, 100, 1);
}
else {
Serial.println("Maximum number of cards stored");
blink(failureLED, 50, 10);
}
}
}
void seekAndDeleteTag() {
Serial.println("Deleting the next card");
Serial.println("Waiting for card");
while(getTag() == 0){
// do nothing; wait for tag
// unless you get a byte of serial data,
if (Serial. available()) {
// break out of the while loop
// and out of the method:
return;
}
}
int tagToDelete = lookupTag(tag[0], tag[1], tag[2], tag[3]);
if (tagToDelete == 200){
Serial.print("That tag is not stored");
}
else {
deleteTag(tagToDelete);
}
}
void toggle(int thisLED) {
toggleState = !toggleState;
digitalWrite(thisLED, toggleState);
}
void blink(int thisLED, int interval, int count) {
for (int i = 0; i < count; i++) {
digitalWrite(thisLED, HIGH);
delay(interval/2);
digitalWrite(thisLED, LOW);
delay(interval/2);
}
}