Hello all, new to the forum and pretty new to Arduino. Working with the Ethernet Rev3 board and a handful of times the IP doesn't seem to 'stick' and the device is not ping-able. I have to cycle power a couple times and it will eventually be accessible. I'm not using DHCP I'm providing the IP, not sure what it could be my code is below.
Basically what is happening is I read an SD card to get the IP that I would like (it is a simple text file with just the IP inside). Then I store that in the ip variable, which has a value as a fallback incase the SD card doesn't read.
Then in the loop it listens for various messages to turn the mag sensors on and off, but when I can't ping it, no messages get to the board of course 
Any help would be greatly appreciated!
#include <SPI.h> // needed for Arduino versions later than 0018
#include <Wire.h>
#include <Ethernet.h>
#include <EthernetUdp.h> // UDP library from: bjoern@cs.stanford.edu 12/30/2008
#include <SD.h> // SD Card Library
//Ethernet Setup.
PROGMEM byte mac[] = { 0x90, 0xA2, 0xDA, 0x0D, 0xE0, 0x50 };
IPAddress ip(10, 201, 1, 39);
IPAddress remoteAddress(10, 201, 1, 24);
unsigned int localPort = 8888; // local port to listen on
boolean receivedStart = false;
char packetBuffer[5]; //buffer to hold incoming packet,
// An EthernetUDP instance to let us send and receive packets over UDP
EthernetUDP Udp;
struct demo_output {
uint8_t magx_h_0;
uint8_t magx_l_0;
uint8_t magy_h_0;
uint8_t magy_l_0;
uint8_t magz_h_0;
uint8_t magz_l_0;
uint8_t magx_h_1;
uint8_t magx_l_1;
uint8_t magy_h_1;
uint8_t magy_l_1;
uint8_t magz_h_1;
uint8_t magz_l_1;
uint8_t magx_h_2;
uint8_t magx_l_2;
uint8_t magy_h_2;
uint8_t magy_l_2;
uint8_t magz_h_2;
uint8_t magz_l_2;
uint8_t magx_h_3;
uint8_t magx_l_3;
uint8_t magy_h_3;
uint8_t magy_l_3;
uint8_t magz_h_3;
uint8_t magz_l_3;
}
my_demo;
void setup()
{
Serial.begin(9600); // start serial communication at 9600bps
Wire.begin(); // join i2c bus as master.
SDSetup(); //Setup SD Card. and set IP
Ethernet.begin(mac, ip); // start the Ethernet:
Udp.begin(localPort); //Start UDP
}
void SDSetup()
{
File myFile;
String IPstr = "";
pinMode(10, OUTPUT);
if (SD.begin(4)) {
myFile = SD.open("IPData.txt");
if (myFile) {
// read from the file until there's nothing else in it:
while (myFile.available()) {
IPstr = IPstr + (char)myFile.read();
}
// close the file:
myFile.close();
Serial.println(IPstr);
char* p;
IPstr.toCharArray(p,IPstr.length()+1);
char* str;
int i = 0;
while ((str = strtok_r(p, ".", &p)) != NULL) // delimiter is the semicolon
{
ip[i] = atoi(str);
i++;
}
} else {
// if the file didn't open, print an error:
Serial.println("error opening IPData.txt");
}
}
}
void loop()
{
int packetSize = Udp.parsePacket();
//Serial.println(packetSize);
if(packetSize)
{
//Store IP as Remote IP
remoteAddress = Udp.remoteIP();
// read the packet into packetBufffer
Udp.read(packetBuffer,5);
//For Testing Only.
Serial.println("Contents:");
Serial.println(packetBuffer);
if (strcmp(packetBuffer,"INIT") == 0)
{
//receivedIP = true;
}
else if (strcmp(packetBuffer,"GOGO") == 0)
{
receivedStart = true;
//receivedIP = true;
}
else if (strcmp(packetBuffer,"STOP") == 0)
{
receivedStart = false;
//receivedIP = true;
}
}
if (receivedStart)
{
//Sensor 0:
i2c_write(0x30, 0x07, 0x80); // Refill Charge Cap
delayMicroseconds(55);
i2c_write(0x30, 0x07, 0x20); //SET Instruction
i2c_write(0x30, 0x07, 0x40); //RESET Instruction
i2c_write(0x30, 0x07, 0x01); // take measurement TM Flag == 1
while ( (i2c_read(0x30, 0x06) & 0x01) != 1 ); // Wait until Measurement Done
//Read 0
my_demo.magx_h_0 = i2c_read(0x30, 0x01);
my_demo.magx_l_0 = i2c_read(0x30, 0x00);
my_demo.magy_h_0 = i2c_read(0x30, 0x03);
my_demo.magy_l_0 = i2c_read(0x30, 0x02);
my_demo.magz_h_0 = i2c_read(0x30, 0x05);
my_demo.magz_l_0 = i2c_read(0x30, 0x04);
//Sensor 1:
i2c_write(0x31, 0x07, 0x80); // Refill Charge Cap
delayMicroseconds(55);
i2c_write(0x31, 0x07, 0x20); //SET Instruction
i2c_write(0x31, 0x07, 0x40); //RESET Instruction
i2c_write(0x31, 0x07, 0x01); // take measurement TM Flag == 1
while ( (i2c_read(0x31, 0x06) & 0x01) != 1 ); // Wait until Measurement Done
//Read 1
my_demo.magx_h_1 = i2c_read(0x31, 0x01);
my_demo.magx_l_1 = i2c_read(0x31, 0x00);
my_demo.magy_h_1 = i2c_read(0x31, 0x03);
my_demo.magy_l_1 = i2c_read(0x31, 0x02);
my_demo.magz_h_1 = i2c_read(0x31, 0x05);
my_demo.magz_l_1 = i2c_read(0x31, 0x04);
//Sensor 2:
i2c_write(0x32, 0x07, 0x80); // Refill Charge Cap
delayMicroseconds(55);
i2c_write(0x32, 0x07, 0x20); //SET Instruction
i2c_write(0x32, 0x07, 0x40); //RESET Instruction
i2c_write(0x32, 0x07, 0x01); // take measurement TM Flag == 1
while ( (i2c_read(0x32, 0x06) & 0x01) != 1 ); // Wait until Measurement Done
//Read 0
my_demo.magx_h_2 = i2c_read(0x32, 0x01);
my_demo.magx_l_2 = i2c_read(0x32, 0x00);
my_demo.magy_h_2 = i2c_read(0x32, 0x03);
my_demo.magy_l_2 = i2c_read(0x32, 0x02);
my_demo.magz_h_2 = i2c_read(0x32, 0x05);
my_demo.magz_l_2 = i2c_read(0x32, 0x04);
Udp.beginPacket(remoteAddress, 8888);
Udp.write(convertObjectToJson());
Udp.endPacket();
}
}
void i2c_write(uint8_t device_address, uint8_t register_address, uint8_t data_write)
{
Wire.beginTransmission(device_address);
Wire.write(byte(register_address));
Wire.write(byte(data_write));
Wire.endTransmission(false);
}
uint8_t i2c_read(uint8_t device_address, uint8_t register_address)
{
uint8_t result;
Wire.beginTransmission(device_address);
Wire.write(byte(register_address));
Wire.endTransmission(false);
Wire.requestFrom(int(device_address),1); //Read 1 byte back..
int i = 0;
while (Wire.available() < 1)
{
//Just Waiting...
i++;
if (i > 50)
{
break;
}
}
result = Wire.read();
return (result);
}
unsigned int CombineBits(uint8_t x_high, uint8_t x_low)
{
unsigned int combined; //We Use Unsigned Int due to 2 bit limitations.
combined = x_high; //send x_high to rightmost 8 bits
combined = combined<<8; //shift x_high over to leftmost 8 bits
combined |= x_low; //logical OR keeps x_high intact in combined and fills in rightmost 8 bits
return combined;
}
char* convertObjectToJson()
{
char charBuf[350];
sprintf(charBuf,
"{\"sensors\":[{\"id\":0,\"data\":{\"xMag\":%u,\"yMag\":%u,\"zMag\":%u}},{\"id\":1,\"data\":{\"xMag\":%u,\"yMag\":%u,\"zMag\":%u}},{\"id\":2,\"data\":{\"xMag\":%u,\"yMag\":%u,\"zMag\":%u}}]}"
,CombineBits(my_demo.magx_h_0,my_demo.magx_l_0),CombineBits(my_demo.magy_h_0,my_demo.magy_l_0),CombineBits(my_demo.magz_h_0,my_demo.magz_l_0),CombineBits(my_demo.magx_h_1,my_demo.magx_l_1),CombineBits(my_demo.magy_h_1,my_demo.magy_l_1),CombineBits(my_demo.magz_h_1,my_demo.magz_l_1),CombineBits(my_demo.magx_h_2,my_demo.magx_l_2),CombineBits(my_demo.magy_h_2,my_demo.magy_l_2),CombineBits(my_demo.magz_h_2,my_demo.magz_l_2));
//Serial.println(charBuf);
return charBuf;
}