A simple example on how to control an arduino board from a smartphone, this time using ethernet NOT bluetooth. The app was created using MIT's app inventor. The module used here is based on the ENC28J60 chip (~$5 on fleabay )
enjoy
Arduino sketch
// A simple web server that shows temperature and controlls an LED
#include "etherShield.h"
#include "ETHER_28J60.h"
#include <OneWire.h>
OneWire ds(A3); // on pin A3
int celsius,celsiusF;
int outputPin = 3; //the LED pin
static uint8_t mac[6] = {
0x54, 0x55, 0x58, 0x10, 0x00, 0x24}; // this just needs to be unique for your network,
// so unless you have more than one of these boards
// connected, you should be fine with this value.
static uint8_t ip[4] = {
192, 168, 1, 15}; // the IP address for your board. Check your home hub
// to find an IP address not in use and pick that
// this or 10.0.0.15 are likely formats for an address
// that will work.
static uint16_t port = 80; // Use port 80 - the standard for HTTP
ETHER_28J60 e;
void setup()
{
Serial.begin(9600);
e.setup(mac, ip, port);
}
void loop()
{
char* params;
if (params = e.serviceRequest())
{
e.print("<H1>Temperature
");
e.print(celsius);
e.print(",");
e.print(celsiusF);
e.print(" C</H1>");
e.print("
");
e.print("
");
e.print("<H1>LED control</H1>");
e.print("<A HREF='?cmd=off'>Turn off</A>
");
e.print("<A HREF='?cmd=on'>Turn on</A>
");
if (strcmp(params, "?cmd=on") == 0)
{
digitalWrite(outputPin, HIGH);
e.print("LED is ON");
}
else if (strcmp(params, "?cmd=off") == 0)
{
digitalWrite(outputPin, LOW);
e.print("LED is OFF");
}
e.respond();
delay(100);
}
else
{
{
byte i;
byte present = 0;
byte type_s;
byte data[12];
byte addr[8];
if ( !ds.search(addr)) {
Serial.println("No more addresses.");
Serial.println();
ds.reset_search();
delay(250);
return;
}
Serial.print("ROM =");
for( i = 0; i < 8; i++) {
Serial.write(' ');
Serial.print(addr[i], HEX);
}
if (OneWire::crc8(addr, 7) != addr[7]) {
Serial.println("CRC is not valid!");
return;
}
Serial.println();
// the first ROM byte indicates which chip
switch (addr[0]) {
case 0x10:
Serial.println(" Chip = DS18S20"); // or old DS1820
type_s = 1;
break;
case 0x28:
Serial.println(" Chip = DS18B20");
type_s = 0;
break;
case 0x22:
Serial.println(" Chip = DS1822");
type_s = 0;
break;
default:
Serial.println("Device is not a DS18x20 family device.");
return;
}
ds.reset();
ds.select(addr);
ds.write(0x44,1); // start conversion, with parasite power on at the end
delay(10); // maybe 750ms is enough, maybe not
// we might do a ds.depower() here, but the reset will take care of it.
present = ds.reset();
ds.select(addr);
ds.write(0xBE); // Read Scratchpad
Serial.print(" Data = ");
Serial.print(present,HEX);
Serial.print(" ");
for ( i = 0; i < 9; i++) { // we need 9 bytes
data[i] = ds.read();
Serial.print(data[i], HEX);
Serial.print(" ");
}
Serial.print(" CRC=");
Serial.print(OneWire::crc8(data, 8), HEX);
Serial.println();
// convert the data to actual temperature
unsigned int raw = (data[1] << 8) | data[0];
if (type_s) {
raw = raw << 3; // 9 bit resolution default
if (data[7] == 0x10) {
// count remain gives full 12 bit resolution
raw = (raw & 0xFFF0) + 12 - data[6];
}
}
else {
byte cfg = (data[4] & 0x60);
if (cfg == 0x00) raw = raw << 3; // 9 bit resolution, 93.75 ms
else if (cfg == 0x20) raw = raw << 2; // 10 bit res, 187.5 ms
else if (cfg == 0x40) raw = raw << 1; // 11 bit res, 375 ms
// default is 12 bit resolution, 750 ms conversion time
}
celsius = abs(raw / 16.0);
celsiusF= (raw / 16.0 - celsius) * 100;
Serial.print(" Temperature = ");
Serial.print(celsius);
Serial.print(",");
Serial.println(celsiusF);
}
}
}
The .apk file is the app iteslf, the zipped file is a source that can be uploaded into MIT's app inventor for experimenting with it. The source file is an archive and it should be uploaded to app inventor as an archive.
arduino_appinventor_version_with_temp(1).apk (1.26 MB)
arduino_appinventor_version_with_temp(1).zip (3.93 KB)
