Minecraft modding has become almost as popular as the block-based game itself, with tons of editors and tools available to create new kinds of blocks, mobs, and weapons. And now, with this mod framework that can talk to an Arduino, modders can build blocks that break out of the Minecraft world to control the real world.

While turning on a light from Minecraft is not exactly new, the way that MCreator for Arduino goes about it is pretty neat. MCreator is a no-code framework for building Minecraft mods, which allows modders to build new game capabilities with a drag and drop interface. The MCreator Arduino toolkit allows modders to build custom Minecraft blocks that can respond to in-game events and communicate with an Arduino over USB. Whatever an Arduino can do – light an LED, sense a button press – can be brought into the game. It’s all open-source and free for non-commercial use, which is perfect for the upcoming STEM-based summer camp season. We can think of some great projects that would really jazz up young hackers when presented through a Minecraft interface.

In this post we present the design of a scale that connects to the Internet and automatically sends weight info on a Google Document.

The project is composed of

• Arduino Uno board
• Wi-Fi shield
• additional shield that we used to manage data collection and I/O with a clear and comfortable and clear LCD display
• Velleman scale (or another commercial product)

Hardware

Taking a look at the diagram, we can distinguish three sections:

one for handling digital inputs (two buttons and scale’s switch),
the LCD manager
the analog signal acquisition from load cells

You may notice that P1 and P2 buttons are respectively managed by Arduino’s A3 and A4 inputs (configured as digital), while the INT switch reads the A5 signal (digital as well).

The LCD display used in our project belongs to the family of those based on HD44780 chipset, equipped with seven-pin control (RW, D4, D5, D6, D7, RS and Enable). As you can see from the diagram, RW is permanently connected to ground so it’s only operating in writing mode.

D4, D5, D6 and D7 pins are respectively managed by 3, 5, 6 and 7 digital pins of the Arduino Uno; RS is managed by pin 8 and the Enable pin from pin A0 (this configuration will also be specified in the software).

Besides the power supply (a VCC connected to 5V) and the ground (GND), the display requires a level of voltage between 0 and 5 volts to adjust the contrast in the input pin VO (adjustment made through R6 potentiometer).

Finally the display has 2 pin (A and K respectively anode and cathode) for switching on the backlight: feeding the pin with a voltage of 5V, the backlight is turned on, otherwise it is off.

The switching on and off is handled via a push-button switch that connects or disconnects the ground from the cathode.

Finally let’s analyze the part that manages the analog signal from the load cells: this is done by INA125 integrated component, a high precision amplifier developed specifically for measuring tools like scales.

The IC is fitted with two pins (6 and 7) representing the input of the differential amplification stage. These pins are connected to the two ends of the Wheatstone bridge (which in our project correspond to two of the load cell pins).

As you can figure out, the differential signal coming from the bridge has an absolute value of just a few millivolts: our project requires an amplification of about 500 times, obtained with a 120 ohm resistor.

The amplified output is provided at pins 10 and 11 of INA125; these pins are connected to A1 analog of the Arduino board, which therefore will be used for reading the value ADC.

Hacking  the Velleman scale

Our system is designed to be matched to the high-capacity scale produced by Velleman. But you can using any scale usign 4 load cells. The original Velleman electronics and display must be phased out and replaced with our project.

The scale structure is made up of 4 load cells (arranged on the 4 corners), which are configured between them so as to create a single Wheatstone bridge.

To make the connection to our board you must disassemble the lower section of the scale in order to access the electronics.

Referring to Fig A, which shows the structure of the scale viewed from below, with a quick visual analysis is easy to figure out that some blue and red wires are connected to each other while the yellow wires are connected to the switches positioned on the front of the two cells that identify the presence of a person.

To hack the scale follow these steps:

• unsolder or cut all the red and blue wires, push in short those that were already shorted previously,

• unsolder or cut the yellow wires coming from the cells numbered 1 and 3, put them in parallel (possibly by welding), extend them and take them to the two terminals on the new INT printed board (Fig.B)

• unsolder or cut the white wire that is referred to as G3 (Wheatstone bridge mass) on the original printed circuit, extend take it to terminal 1 on the new printed circuit;

• unsolder or cut the white wire that is referred to as G2 (Wheatstone bridge positive) on the original printed circuit, extend take it to terminal 3 on the new printed circuit;

• unsolder or cut the white wire that is referred to as G1 and G4 on the original printed circuit, extend take it to terminal 4 and 2 on the new printed circuit (differential signal on the Wheatstone bridge)

The Sketch

As for the LCD, Arduino provides a convenient library (<LiquidCrystal.h>) already supporting different kinds of LCD (both 8 and 16 chars for 2 lines) based on the parallel interface chipset HD44780.

After the inclusion of the library, you must initialize the connection to the display, through LiquidCrystal LCDDisplay (8, A0, 3, 5, 6, 7), in this command, the parameters passed to the function and indicate Arduino’s hardware pins used to connect RS, Enable, D4, D5, D6 and D7 pins of the display.

Depending on the Arduino setup could be necessary to execute LCDDisplay.begin (width, height) in which the parameters indicate the physical dimensions of the display: LCDDisplay.begin (8, 2) in this case.

The library makes available instructions:

• LCDDisplay.setCursor (x, y) to position the cursor in a certain position

• LCDDisplay.print (String) to print strings

Management of Arduino’s EEPROM is done by the <EEPROM.h> library  that, once included, provides the functions:

• EEPROM.write (add, date) to write a byte in a particular cell and

• EEPROM.read (add) that the instead reads a byte from one cell (the add parameter specifies the address of the EEPROM cell).

Wi-Fi network and internet connection are managed thanks to the <WiServer.h> library; you just need to define some variables to configure the network (like IP’s and Network masks).

The adapter to connect and publish data on Google Documents shall operate as a Web Client: this configuration is done in the setup instruction WiServer.init (NULL) in which the NULL parameter specifies client mode.

You must create a function that will receive and handle the response from the server, this is done by the googlePublish.setReturnFunc  (Gestione_Risposte_Web) instruction  in our example. This function must be defined later in the code: in our example is void Gestione_Risposte_Web (char * data, int len) and receives as parameters both a pointer to a string containing the response and the length (in bytes) of the response.

Sending information requires to make a POST request to Google’s servers: WiServer library makes available a POSTrequest just to do this.

You must define the IP address of the server to which you want to connect (Google in our case) and define a structure of the POSTrequest (in our case, the variable is called googlePublish) containing the IP address of the server, the TCP / IP port the server name (spreadsheets.google.com), URL of POST execution and finally a function (SearchQuery in our case) that builds POST request body.

/******************************************************
 BilanciaWiFi
 Autori: Ingg. Tommaso Giusto e Ing. Alessandro Giusto
 Email:  tommro@libero.it
******************************************************/

// Inclusione Libreria per Display LCD 8x2
#include <LiquidCrystal.h>
// Inclusione Libreria per EEPROM scheda
#include <EEPROM.h>
// Inclusione Libreria per Server Web WiFi
#include <WiServer.h>
// Inclusione Libreria per SD Card
//#include <SD.h>

// Definizione pin INPUT/OUTPUT
const int PinVPeso = A1;         // Ingresso analogico uscita peso
const int PinPulsanteP1 = A3;    // Ingresso pulsante P1 su A3
const int PinPulsanteP2 = A4;    // Ingresso pulsante P2 su A4
const int PinInterruttore = A5;  // Ingresso interruttore su A5

// Definizione/Inizializzazione PIN Display LCD
// LCD RS pin D8
// LCD Enable on pin A0
// LCD D4, D5, D6, D7 on pins D3, D5, D6, D7
// LCD R/W pin a massa
// LCD V0 pin trimmer tra +5V e massa
LiquidCrystal LCDDisplay (8, A0, 3, 5, 6, 7);

/******************************************************
 Definizione struttura EEPROM
******************************************************/

/*****************************************************/
// Byte 0x000        Nome
// ...               Utente
// Byte 0x01F        000 (0x00 Carattere fine stringa)
// ...               
// ...               
// ...               
// Byte 0x120        Nome
// ...               Utente
// Byte 0x13F        009 (0x00 Carattere fine stringa)
/*****************************************************/
#define StartNomiUtentiEEPROMADD          0x0000
#define EndNomiUtentiEEPROMADD            0x013F
#define DimensioneNomeUtenteEEPROMADD     32
#define NumMaxNomiUtenti                  10

/*****************************************************/
// Byte 0x140        Parte Alta Peso Utente 000
// Byte 0x141        Parte Bassa Peso Utente 000
// ...               
// ...               
// ...               
// Byte 0x152        Parte Alta Peso Utente 009
// Byte 0x153        Parte Bassa Peso Utente 009
/*****************************************************/
#define StartPesiUtentiEEPROMADD          0x0140
#define EndPesiUtentiEEPROMADD            0x0153
#define DimensionePesoUtenteEEPROMADD     2

#define PesoMIN                           100
#define PesoMAX                           2000
#define AnalogDifferenzaPesoMAX           15

#define CalibrazioneSensoreMIN            0
#define CalibrazioneSensoreMAX            80

/******************************************************
 Definizione variabili globali
******************************************************/

// Definizione Parametri Rete Wireless
#define WIRELESS_MODE_INFRA	1  // Infrastrutturata (basata su Access Point)
#define WIRELESS_MODE_ADHOC	2  // Ad-hoc (senza Access Point)

// Parametri di rete
unsigned char local_ip[] = {192, 168, 0, 89};      // Indirizzo IP
unsigned char gateway_ip[] = {192, 168, 0, 254};	    // Indirizzo gateway IP
unsigned char subnet_mask[] = {255, 255, 255, 0};   // Subnet Mask
const prog_char ssid[] PROGMEM = {"FlashMob"};	    // SSID access point

// Selezione tipo di cifratura rete Wireless
unsigned char security_type = 0;  // 0 -> nessuna cifratura
                                  // 1 -> cifratura WEP
                                  // 2 -> cifratura WPA
                                  // 3 -> cifratura WPA2

// Password cifratura per WPA/WPA2 (max. 64 cratteri)
const prog_char security_passphrase[] PROGMEM = {"12345678"};

// Password cifratura per WEP 128-bit keys
prog_uchar wep_keys[] PROGMEM = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
				 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
				 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

// Selezione tipo di rete Wireless infrastrutturata
unsigned char wireless_mode = WIRELESS_MODE_INFRA;

// Variabili per lunghezza SSID e password di cifratura
unsigned char ssid_len;
unsigned char security_passphrase_len;

// Definizione Parametri Pubblicazione Google
// Indirizzo IP per server www.google.it
uint8 google_ip[] = {209, 85, 229, 101};

// Richiesta POST verso GOOGLE
POSTrequest googlePublish (google_ip, 80, "spreadsheets.google.com", "", searchQuery);

// Stringa per eseguire pubblicazione
char newURL[] = {"/formResponse?formkey=dDFPcWhxNlZxMEpnUnhNdE5fT1lDcWc6MQ&ifq&entry.0.single=++++++++++++++++++++++++++++++++&entry.1.single=999,9&submit=Submit"};

// This function generates the body of our POST request
void searchQuery() {
}

// Indica presenza SD Card
//boolean presenzaSDCard;

// Inizializzazione Scheda
void setup() {
  // Inizializzo dimensioni LCD (8x2)
  LCDDisplay.begin (8, 2);

  // Inizializzo pin usati come INPUT/OUTPUT
  pinMode (PinInterruttore, INPUT);  
  pinMode (PinPulsanteP1, INPUT);
  pinMode (PinPulsanteP2, INPUT);

  // Se all'accensione rilevati tutti e 2 i pulsanti premuti
  if ((PulsantePremuto (PinPulsanteP1) == 1) &&
      (PulsantePremuto (PinPulsanteP2) == 1)) {
    // Segnalo inizializzazione in corso
    LCDDisplay.setCursor (0, 0);
    LCDDisplay.print ("Init EEP");
    LCDDisplay.setCursor (0, 1);
    LCDDisplay.print ("in corso");

    // Inizializzo EEPROM scheda
    InizializzaEEPROM();
    // Attesa
    delay (500);
  }
  // Inizializzo porta seriale
  Serial.begin (9600);  
  Serial.println ("Bilancia WiFi");
  Serial.println ("By Ingg. Tommaso e Alessandro Giusto");
  // Invio stato utenti
  InviaProgrammazioneUtenti();

  // Segnalo Avvio Web
  LCDDisplay.setCursor (0, 0);
  LCDDisplay.print ("  Init  ");
  LCDDisplay.setCursor (0, 1);
  LCDDisplay.print ("  web   ");  

  // Inizializzo WiServer
  WiServer.init (NULL);
  WiServer.enableVerboseMode (false);

  // Inizializzazione richiesta POST (parametro indica funzione a cui verra' passata la risposta)
  googlePublish.setReturnFunc (Gestione_Risposte_Web);    

/*
  // Inizializzo SD Card
  pinMode(10, OUTPUT);  
  presenzaSDCard = SD.begin (4);
  // Se inizializzazione SD fallita  
  if (presenzaSDCard == false)
    Serial.println ("Init SD FAULT!");
  // Se inizializzazione SD riuscita
  else
    Serial.println ("Init SD OK!");
*/
}

// Programma Principale
void loop() {
  // Ciclo infinito di esecuzione
  for (;;) {
    // Gestione Peso
    GestionePeso();

    // Per circa 1 sec
    for (byte tmp = 0; tmp < 250; tmp++) {
      // Gestione programmazione seriale
      GestioneSeriale();
      // Gestione WiServer
      GestioneWiServer();
      // Attesa
      delay (4);
    }    // Chiusura ciclo for per circa 1 sec
  }    // Chiusura ciclo infinito di esecuzione
}

/******************************************************
 Definizione funzioni
******************************************************/

// Funzione Gestione Peso
void GestionePeso() {
  // Indice utente selezionato
  //    0,..,(NumMaxNomiUtenti-1) -> selezionato utente 1,..,NumMaxNomiUtenti
  //    0xFF -> nessun utente selezionato
  static int IndiceUtenteSelezionato = 0xFF;
  // Indica l'indice carattere visualizzato  
  static int IndiceCarattere = 0;
  String NomeUtenteSelezionato;
  int PesoUtenteSelezionato;
  int LunghezzaNomeUtenteSelezionato;
  int ValoreSensorePeso1, ValoreSensorePeso2;
  int ValoreSensorePesoTMP1, ValoreSensorePesoTMP2, ValoreSensorePesoTMP3, ValoreSensorePesoTMP4;
  static int CalibrazioneSensore;
  int CalibrazioneSensoreTMP;
  int PesoCalcolato;
  int tmp;

  // Se non premuto interruttore (utente non salito)
  if (PulsantePremuto (PinInterruttore) == 0) {
    // Leggo valore sensore per calibrazione
    CalibrazioneSensoreTMP = analogRead (PinVPeso);
    // Se valore sensore per calibrazione valido
    if ((CalibrazioneSensoreTMP >= (int) (CalibrazioneSensoreMIN)) &&
      (CalibrazioneSensoreTMP <= (int) (CalibrazioneSensoreMAX)))
      // Aggiorno valore sensore per calibrazione
      CalibrazioneSensore = CalibrazioneSensoreTMP;
  }    // Chiusura if non premuto interruttore (utente non salito)

  // Se premuto tasto 1
  if (PulsantePremuto (PinPulsanteP1) == 1) {
    // Azzero indice carattere visualizzato
    IndiceCarattere = 0;

    // Verifico tutte le posizioni utente
    for (tmp = 0; tmp < NumMaxNomiUtenti; tmp++) {
      // Seleziono utente selezionato
      switch (IndiceUtenteSelezionato) {
        // Se selezionato ultimo utente/nessun utente selezionato
        case (NumMaxNomiUtenti - 1): case 0xFF:
          // Seleziono primo utente
          IndiceUtenteSelezionato = 0;
          break;    // Chiusura case selezionato ultimo utente/nessun utente selezionato

        // Se selezionato altro utente
        default:
          // Seleziono prossimo utente
          IndiceUtenteSelezionato++;
          break;    // Chiusura case nessun utente selezionato
      }    // Chiusura switch seleziono utente selezionato

      // Se trovato utente con nome non nullo
      if (LeggiNomeUtente (IndiceUtenteSelezionato).length() != 0x00)
        // Blocco ciclo for verifico tutte le posizioni utente
        break;
    }    // Chiusura ciclo for verifico tutte le posizioni utente

    // Se non trovato utente con nome non nullo
    if (tmp == NumMaxNomiUtenti)
      // Seleziono nessun utente
      IndiceUtenteSelezionato = 0xFF;
  }    // Chiusura if premuto tasto 1

  // Se utente selezionato
  if (IndiceUtenteSelezionato != 0xFF) {
    // Leggo nome/peso utente
    NomeUtenteSelezionato = LeggiNomeUtente (IndiceUtenteSelezionato);
    PesoUtenteSelezionato = LeggiPesoUtente (IndiceUtenteSelezionato);
    // Calcolo lunghezza nome utente    
    LunghezzaNomeUtenteSelezionato = NomeUtenteSelezionato.length();
    // Seleziono lunghezza nome utente
    switch (LunghezzaNomeUtenteSelezionato) {
      case 0:
        // Indico nessun utente selezionato
        IndiceUtenteSelezionato = 0xFF;
        break;
      case 1: case 2: case 3: case 4: case 5: case 6: case 7:
        LCDDisplay.clear();
        LCDDisplay.setCursor ((8 - LunghezzaNomeUtenteSelezionato) / 2, 0);
        LCDDisplay.print (NomeUtenteSelezionato);
        break;
      case 8:
        LCDDisplay.setCursor (0, 0);
        LCDDisplay.print (NomeUtenteSelezionato);
        break;
      default:
        if ((IndiceCarattere + 8) > LunghezzaNomeUtenteSelezionato)
          IndiceCarattere = 0;

        LCDDisplay.setCursor (0, 0);
        LCDDisplay.print (&NomeUtenteSelezionato[IndiceCarattere]);

        // Messaggio scorrevole
        IndiceCarattere++;
        if ((IndiceCarattere + 8) > LunghezzaNomeUtenteSelezionato)
          IndiceCarattere = 0;
        break;
    }    // Chiusura switch seleziono lunghezza nome utente
    LCDDisplay.setCursor (0, 1);
    LCDDisplay.print (PesoUtenteSelezionato / 1000);
    LCDDisplay.print ((PesoUtenteSelezionato % 1000) / 100);
    LCDDisplay.print ((PesoUtenteSelezionato % 100) / 10);
    LCDDisplay.print (".");
    LCDDisplay.print (PesoUtenteSelezionato % 10);    
    LCDDisplay.print (" Kg");

    // Se premuto interruttore (utente salito)
    if (PulsantePremuto (PinInterruttore) == 1) {
      LCDDisplay.setCursor (0, 1);
      LCDDisplay.print ("..... Kg");

      // Leggo valore analogico peso
      for (;;) {
        // Attesa
        delay (500);
        // Eseguo prima lettura peso
        ValoreSensorePesoTMP1 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePesoTMP2 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePesoTMP3 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePesoTMP4 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePeso1 = ((ValoreSensorePesoTMP1 + ValoreSensorePesoTMP2 + ValoreSensorePesoTMP3 + ValoreSensorePesoTMP4) / 4);

        // Attesa
        delay (500);
        // Eseguo seconda lettura peso
        ValoreSensorePesoTMP1 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePesoTMP2 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePesoTMP3 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePesoTMP4 = analogRead (PinVPeso);
        delay (125);
        ValoreSensorePeso2 = ((ValoreSensorePesoTMP1 + ValoreSensorePesoTMP2 + ValoreSensorePesoTMP3 + ValoreSensorePesoTMP4) / 4);

        // Se peso stabilizzato
        if ((ValoreSensorePeso1 <= ValoreSensorePeso2) && ((ValoreSensorePeso2 - ValoreSensorePeso1) < (int) (AnalogDifferenzaPesoMAX)) ||
            (ValoreSensorePeso1 > ValoreSensorePeso2) && ((ValoreSensorePeso1 - ValoreSensorePeso2) < (int) (AnalogDifferenzaPesoMAX)))
          // Blocco ciclo for leggo valore analogico peso
          break;
      }    // Chiusura ciclo for leggo valore analogico peso

      // Calcolo peso utente
      PesoCalcolato = (int) (ValoreSensorePeso2 - CalibrazioneSensore);
      PesoCalcolato = (PesoCalcolato + (((int) (PesoCalcolato * (int) (10))) / (int) (62)));

//    68.1 KG
//    642   con calibrazione: 62 -> Veff = 580

      // Se peso valido
      if ((PesoCalcolato >= (int) (PesoMIN)) && (PesoCalcolato <= (int) (PesoMAX))) {
        // Memorizzo peso utente
        ScriviPesoUtente (IndiceUtenteSelezionato, PesoCalcolato);

        // Visualizzo peso calcolato
        LCDDisplay.setCursor (0, 1);
        LCDDisplay.print (PesoCalcolato / 1000);
        LCDDisplay.print ((PesoCalcolato % 1000) / 100);
        LCDDisplay.print ((PesoCalcolato % 100) / 10);
        LCDDisplay.print (".");
        LCDDisplay.print (PesoCalcolato % 10);    
        LCDDisplay.print (" Kg");

        // Richiedo pubblicazione        
        LCDDisplay.setCursor (0, 0);
        LCDDisplay.print ("Pubblic?");

        // Per massimo 5 secondi attendo pressione tasto 2
        for (tmp = 0; tmp < 10; tmp++) {
          // Se premuto tasto 2
          if (PulsantePremuto (PinPulsanteP2) == 1) {
            // Indico pubblicazione in corso     
            LCDDisplay.setCursor (0, 0);
            LCDDisplay.print ("Pubblic.");
            LCDDisplay.setCursor (0, 1);
            LCDDisplay.print ("  wait  ");

            // Eseguo pubblicazione
            for (tmp = 0; tmp < NomeUtenteSelezionato.length(); tmp++) {
              newURL[76 + tmp] = NomeUtenteSelezionato.charAt(tmp);
              if (newURL[76 + tmp] == ' ')
                newURL[76 + tmp] = '+';
            }
            newURL[124] = ((PesoCalcolato / 1000) + 0x30);
            newURL[125] = (((PesoCalcolato % 1000) / 100) + 0x30);      
            newURL[126] = (((PesoCalcolato % 100) / 10) + 0x30);      
            newURL[128] = ((PesoCalcolato % 10) + 0x30);      
            googlePublish.setURL(newURL);
            googlePublish.submit();    
            delay (500);
            // Blocco ciclo for
            break;
          }
          delay (500);          
        }    // Chiusura ciclo for per massimo 5 secondi attendo pressione tasto 2
/*
        // Se SD rilevata
        if (presenzaSDCard == true) {
          // Verifico/Creo directory BilanciaWiFi
          if (!(SD.exists ("BilanciaWiFi")))
            SD.mkdir ("BilanciaWiFi");

          // Memorizzo il peso su file
          File filePeso;
          // Apro il file in scrittura
          char nomeFilePeso[50] = {"BilanciaWiFi/"};
          for (tmp = 0; tmp < NomeUtenteSelezionato.length(); tmp++) {
            charTmp[0] = NomeUtenteSelezionato.charAt(tmp);
            strcat (nomeFilePeso, charTmp);
          }
          strcat (nomeFilePeso, ".txt");          
          filePeso = SD.open (nomeFilePeso, FILE_WRITE);

          // Se apertura file OK
          if (filePeso) {
            // Memorizzo il peso
            filePeso.print ((PesoCalcolato / 1000) + 0x30);
            filePeso.print (((PesoCalcolato % 1000) / 100) + 0x30);
            filePeso.print (((PesoCalcolato % 100) / 10) + 0x30);
            filePeso.print (".");
            filePeso.print ((PesoCalcolato % 10) + 0x30);
            filePeso.print (" Kg");
            // Chiudo il file:
            filePeso.close();
          }
        }
*/

        LCDDisplay.setCursor (0, 0);
        LCDDisplay.print ("  Step  ");
        LCDDisplay.setCursor (0, 1);
        LCDDisplay.print ("  off   ");

        // Attendo utente scende dalla bilancia
        for (;;) {
          // Se non premuto interruttore (utente non salito)
          if (PulsantePremuto (PinInterruttore) == 0)
            break;
        }
      }    // Chiusura if peso valido
    }    // Chiusura if premuto interruttore (utente salito)
  }    // Chiusura if utente selezionato

  // Se nessun utente selezionato
  else {
    LCDDisplay.setCursor (0, 0);
    LCDDisplay.print (" Chose  ");
    LCDDisplay.setCursor (0, 1);
    LCDDisplay.print (" user   ");
  }    // Chiusura if nessun utente selezionato
}

// Funzione Gestione Seriale
void GestioneSeriale() {
  String comandoRicevutoString = "";
  int numeroUtenteRicevuto;
  String nomeUtenteRicevuto = "";

  // Se ricevuti dati dalla porta seriale
  if (Serial.available()) {
    // Attendo tutti i dati
    delay (250);

    // Ricevo i dati
    while (Serial.available())
      comandoRicevutoString += (char) (Serial.read());

    // Invio comando ricevuto    
    Serial.println (comandoRicevutoString);

    // Se ricevuti almeno 15 caratteri
    if (comandoRicevutoString.length() >= 15) {
      // Se ricevuto comando programmazione nome utente (NOME_UTENTE_xx=)USER_NAME_01=Boris
      if ((comandoRicevutoString.substring (0, 12).equals("P_USER_NAME_")) &&
          (isdigit(comandoRicevutoString.charAt (12))) &&
          (isdigit(comandoRicevutoString.charAt (13)))) {
        // Estraggo numero utente ricevuto
        numeroUtenteRicevuto = (((comandoRicevutoString.charAt (12) - 0x30) * 10) +
                                (comandoRicevutoString.charAt (13) - 0x30));
        // Se ricevuto numero utente corretto
        if ((numeroUtenteRicevuto >= 1) && (numeroUtenteRicevuto <= NumMaxNomiUtenti)) {
          // Estraggo nome utente
          nomeUtenteRicevuto = comandoRicevutoString.substring (15);
          // Se nome troppo lungo
          if (nomeUtenteRicevuto.length() > DimensioneNomeUtenteEEPROMADD)
            // Tronco il nome
            nomeUtenteRicevuto = nomeUtenteRicevuto.substring (0, DimensioneNomeUtenteEEPROMADD);

          // Memorizzo il nome
          ScriviNomeUtente (numeroUtenteRicevuto - 1, nomeUtenteRicevuto);
          // Azzero il relativo peso
          AzzeraPesoUtente (numeroUtenteRicevuto - 1);
          // Indico OK
          Serial.println ("OK");
          // Invio su  porta seriale lo stato utenti
          InviaProgrammazioneUtenti();
          // Termino funzione
          return;
        }
      }
    }  

    // Indico errore
    Serial.println ("FAULT");
    // Termino funzione
    return;
  }
}

// Invia su  porta seriale lo stato utenti
void InviaProgrammazioneUtenti() {
  for (int numeroUtente = 0; numeroUtente < NumMaxNomiUtenti; numeroUtente++) {
    Serial.print ("Us. ");
    Serial.print ((numeroUtente + 1) / 10);
    Serial.print ((numeroUtente + 1) % 10);
    Serial.print (": ");
    Serial.println (LeggiNomeUtente (numeroUtente));
  }
}

// Funzione Gestione WiServer
void GestioneWiServer() {
  // Gestione WiServer
  WiServer.server_task();
}

// Gestione diverse risposte provenienti dal WEB
void Gestione_Risposte_Web (char* data, int len) {

  // Print the data returned by the server
  // Note that the data is not null-terminated, may be broken up into smaller packets, and 
  // includes the HTTP header. 
  while (len-- > 0) {
    Serial.print(*(data++));
  } 

}

// Scrive il nome di un utente
// INPUT:   Posizione utente (0,..,9)
//          Nome utente in formato stringa
// OUTPUT:  -
// Note:    -
void ScriviNomeUtente (int NomePosition, String NomeUtente) {
  // Azzero nome utente selezionato
  AzzeraNomeUtente (NomePosition);

  // Scrivo i caratteri nome utente selezionato
  for (int tmp = 0; tmp < NomeUtente.length(); tmp++)
    EEPROM.write (StartNomiUtentiEEPROMADD + tmp +
                  (NomePosition * DimensioneNomeUtenteEEPROMADD), NomeUtente.charAt(tmp));
}

// Legge il nome di un utente
// INPUT:   Posizione utente (0,..,9)
// OUTPUT:  Nome utente in formato stringa
// Note:    -
String LeggiNomeUtente (int NomePosition) {
  String NomeUtente = "";
  char NomeUtenteChar;

  // Leggo i caratteri nome utente selezionato
  for (int tmp = 0; tmp < DimensioneNomeUtenteEEPROMADD; tmp++) {
    // Leggo singolo carattere
    NomeUtenteChar = EEPROM.read (StartNomiUtentiEEPROMADD + tmp +
                                  (NomePosition * DimensioneNomeUtenteEEPROMADD));

    // Se trovato carattere fine nome
    if (NomeUtenteChar == 0x00)
      // Blocco ciclo for leggo i caratteri nome utente selezionato
      break;

    // Accodo carattere letto
    NomeUtente = NomeUtente + NomeUtenteChar;
  }

  // Ritorno il nome
  return (NomeUtente);
}

// Azzera il nome di un utente
// INPUT:   Posizione utente (0,..,9)
// OUTPUT:  -
// Note:    -
void AzzeraNomeUtente (int NomePosition) {
  // Azzero caratteri nome utente selezionato
  for (int tmp = 0; tmp < DimensioneNomeUtenteEEPROMADD; tmp++)
    EEPROM.write (StartNomiUtentiEEPROMADD + tmp +
                  (NomePosition * DimensioneNomeUtenteEEPROMADD), 0); 
}

// Scrive il peso di un utente
// INPUT:   Posizione utente (0,..,9)
//          Peso utente
// OUTPUT:  -
// Note:    -
void ScriviPesoUtente (int PesoPosition, int PesoUtente) {
  // Memorizzo peso nome utente
  EEPROM.write (StartPesiUtentiEEPROMADD + 
                (PesoPosition * DimensionePesoUtenteEEPROMADD), (byte) (PesoUtente >> 8));
  EEPROM.write (StartPesiUtentiEEPROMADD + 1 +
                (PesoPosition * DimensionePesoUtenteEEPROMADD), (byte) (PesoUtente & 0x00FF));
}

// Legge il peso di un utente
// INPUT:   Posizione utente (0,..,9)
// OUTPUT:  Peso utente
// Note:    -
int LeggiPesoUtente (int PesoPosition) {
  // Ritorno il peso
  return (((int) (EEPROM.read (StartPesiUtentiEEPROMADD +
                               (PesoPosition * DimensionePesoUtenteEEPROMADD))) << 8) +
           (int) (EEPROM.read (StartPesiUtentiEEPROMADD + 1 +
                               (PesoPosition * DimensionePesoUtenteEEPROMADD))));
}

// Azzera il peso di un utente
// INPUT:   Posizione utente (0,..,9)
// OUTPUT:  -
// Note:    -
void AzzeraPesoUtente (int PesoPosition) {
  // Azzero peso nome utente
  ScriviPesoUtente (PesoPosition, 0);
}

// Inizializza EEPROM scheda
// INPUT:   -
// OUTPUT:  -
// Note:    -
void InizializzaEEPROM() {
  // Azzero i nomi/pesi di tutti gli utenti
  for (int tmp = 0; tmp < NumMaxNomiUtenti; tmp++) {
    AzzeraNomeUtente (tmp);
    AzzeraPesoUtente (tmp);
  }    
}

// Verifica lo stato di un pulsante
// INPUT:   Pin pulsante
// OUTPUT:  Stato pulsante    0 -> pulsante non premuto
//                            1 -> pulsante premuto
// Note:    -
int PulsantePremuto (int PinPulsante) {
  if (digitalRead (PinPulsante) == LOW)
    return (1);
  else
    return (0);
}

Install the WiShield libraries

To work properly, the Wifi shield requires specific libraries that must be installed in the Arduino IDE used to compile the sources so you’ll need to put these libraries in the Arduino libraries path.

The library supports multiple operating modes (APP_WEBSERVER, APP_WEBCLIENT, APP_SOCKAPP, APP_UDPAPP and APP_WISERVER).

The default value is APP_WEBSERVER, which runs on most Arduino systems but has several limitations. The main limitation is that it can’t function both as a client and server simultaneously.

It is therefore recommended the APP_WISERVER (in the library named “WiServer.h“) which allows the Arduino shield equipped with Wi-Fi to be configured and operated either as a Web Server as a Web Client.

In the first case, you can serve connection requests from external web clients and send HTML pages in response, in the second it will be possible to connect to a web server and send GET or POST requests.

To configure the WiShield library as APP_WISERVER you must open the apps-conf.h file, comment the “#define“ APP_WEBSERVER row and uncomment the “#define” of APP_WISERVER row.

Something like:

/ / # define APP_WEBSERVER

/ / # define APP_WEBCLIENT

/ / # define APP_SOCKAPP

/ / # define APP_UDPAPP

# defineAPP_WISERVER

Configuring publishing

Performing data publication on Google Documents requires three distinct steps:

1. Configuring Wi-Fi network access;
2. Creating a Google Docs form module: each module is characterized by an identifying 34 characters string – FormKey) and each field is characterized by an identification number (called Entry).
3. Inserting the FormKey / Entry in the Arduino software.

Configuring network parameters

First you must configure and update the IP address, Subnet Mask, Gateway IP and Network SSID, then select the encryption mode and change password information for your network. Save all, compile and run the upload Software tab.

Creating the Google  module doc

Create a form on Google Docs, modify the form with two fields (username and weight, both of type string) and save the job. (the result is something like the one shown in Figure). In our case, we left the default file name and called the two fields “User Name” and “User weight”

take note of this key string because then it will be inserted in the Arduino software: as you can see from the picture, the link shows the form key assigned to the module (in this example, the link is: https://docs.google.com/spreadsheet/viewform?formkey=dDFPcWhxNlZxMEpnUnhNdE5fT1lDcWc6MQ which implies that the form assigned key is “dDFPcWhxNlZxMEpnUnhNdE5fT1lDcWc6MQ”);

Clicking on the link will open a new page that shows the data entry form: within this form text fields are marked with “entry.0.single“, “entry.1.single“, etc … (basically with an integer id)

 To see which number has been assigned to our fields you need to display the HTML source of the form (the result is something like the one shown in this Figure).

You can easily find the ID numbers assigned to different fields (in our example “entry.0.single” is the “Name” and “entry.1.single” is the “weight“).

Take note of this information because it will be included in the source Arduino as well.

Formkey / entry

Once you have created the form, the Arduino source will be configured so that it is compatible with the form you created.

A variable is defined in Arduino source named newURL[]: the variable is initialized with a standard format then modified to perform publication (refer to Figure 11 to identify it in the code).

Replace the default values with those obtained at the time of the creation of the form, compile and download it to the Arduino board.

How to program user names

The configuration of user names can be made via serial port and Serial Monitor. To program it, connect to the board (via USB cable) and open the Arduino Serial Monitor. As a first step the card sends a summary of the current configuration.

To program a new user name you must send a string in the format “P_USER_NAME_xx = User Name” with xx between 01 and 10 ID (put an empty string to delete the selected user.) If all the posted information is correct, this is confirmed by the message “Ok” otherwise “Fault”.

Using the scale

The scale software is able to distinguish up to 10 users (each identified by its name) and, for each one, it stores the last measured weight.

If you want to clear the memory (which we recommend at first use) is sufficient to hold down either of the two buttons (the display indicates the operation with “EEP init in progress”).

Later, you can configure names following the procedure described in the “Programming user names” section.

As the next step the Web management interface will start and the system will enter its normal operation. The user selection is done by pressing button P1.

Going over the scale starts the weighing procedure (lasting several seconds): weight is displayed and stored and the scale asks for publishing on the web: by pressing P2 the operation is performed.

We create a lamp controlled by SMS using a GSM shield, a RGB shield and a Arduino UNO.
Due to the simplicity of these boards, simply plug one over the other and connect a strip led to have a lighting effect.
Then sending normal text messages from any phone, you can turn on and choose the color to set.

The scketch check the text of the received message, if the SMS contains a character, it follows on the corresponding color.
It ‘also provided a fader functions can be called with the character F

This is the list commands:
R to set RED
G to set GREEN
B to set BLUE
Y to set YELLOW
O to set ORANGE
P to set PURPLE
W to set WHITE
F to set the fader function

This is just an example of the possible applications of the GSM / GPRS shield.
You can for example control the home lighting with a simple text message, or receive an SMS in case of alarm.
In addition, the SIM900 has the capacity to also decode DTMF tones, so you can call this in the sim GSM shield and switch loads directly from the telephone keypad.

The complete library it contains many other functions through which you can make calls, connect to the Internet, send and receive SMS.

This is the simple firmware in Arduino.

//GSM Shield for Arduino
//www.open-electronics.org
//this code is based on the example of Arduino Labs

#include "SIM900.h"
#include "sms.h"
#include "SoftwareSerial.h"
#include "sms.h"
SMSGSM sms;
int red = 10;    // RED LED connected to PWM pin 3
int green = 5;    // GREEN LED connected to PWM pin 5
int blue = 6;    // BLUE LED connected to PWM pin 6
int r=50; int g=100; int b=150;
int rup; int gup; int bup;

boolean started=false;
char smsbuffer[160];
char n[20];
int fader=1;
int inc=10;

void setup() 
{
  //Serial connection.
  Serial.begin(9600);
  Serial.println("GSM Shield testing.");
  //Start configuration of shield with baudrate.
  if (gsm.begin(2400)){
    Serial.println("\nstatus=READY");
    started=true;  
  }
  else Serial.println("\nstatus=IDLE");
  if(started){
    delsms();
  }

};

void loop() 
{
  int pos=0;
  //Serial.println("Loop");
  if(started){
    pos=sms.IsSMSPresent(SMS_ALL);
    if(pos){
      Serial.println("IsSMSPresent at pos ");
      Serial.println(pos); 
      sms.GetSMS(pos,n,smsbuffer,100);
        Serial.println(n);
        Serial.println(smsbuffer);
        if(!strcmp(smsbuffer,"R")){
          Serial.println("RED");
          r=255;
          g=0;
          b=0;
        }      
        if(!strcmp(smsbuffer,"G")){
          Serial.println("GREEN");
          r=0;
          g=255;
          b=0;
        }    
        if(!strcmp(smsbuffer,"B")){
          Serial.println("BLUE");
          r=0;
          g=0;
          b=255;
        }  
        if(!strcmp(smsbuffer,"P")){
          Serial.println("PURPLE");
          r=255;
          g=0;
          b=255;
        }  
        if(!strcmp(smsbuffer,"Y")){
          Serial.println("YELLOW");
          r=255;
          g=255;
          b=0;
        }  
        if(!strcmp(smsbuffer,"O")){
          Serial.println("ORANGE");
          r=255;
          g=165;
          b=0;
        }  
        if(!strcmp(smsbuffer,"W")){
          Serial.println("WHITE");
          r=255;
          g=255;
          b=255;
        }  
        if(!strcmp(smsbuffer,"F")){
          Serial.println("FADER");
          fader=1;
          r=50; g=100; b=150;
        }
        else
        {
          fader=0;
        }  
        rgb(r, g, b);
        delsms();

    }
    if(fader){
      funcfader();
    }

  }
};

void delsms(){
  Serial.println("delsms");
  for (int i=0; i<10; i++){  //do it max 10 times
      int pos=sms.IsSMSPresent(SMS_ALL);
      if (pos!=0){
        Serial.print("\nFind SMS at the pos ");
        Serial.println(pos); 
        if (sms.DeleteSMS(pos)==1){    
          Serial.print("\nDeleted SMS at the pos ");
          Serial.println(pos);      
        }
        else
        {
          Serial.print("\nCant del SMS at the pos ");
          Serial.println(pos);         
        }
      }
    }

}

void funcfader(){
    if (rup==1){r+=1;}
    else{r-=1;}
    if (r>=255){rup=0;}
    if (r<=0){rup=1;}

    if (gup==1){g+=1;}
    else{g-=1;}
    if (g>=255){gup=0;}
    if (g<=0){gup=1;}

    if (bup==1){b+=1;}
    else{b-=1;}
    if (b>=255){bup=0;}
    if (b<=0){bup=1;}  
    rgb(r, g, b);
}

void rgb(int r, int g, int b)
{

  if (r>255) r=255;
  if (g>255) g=255;
  if (b>255) b=255;
  if (r<0) r=0;
  if (g<0) g=0;
  if (b<0) b=0;

  analogWrite(red, r); 
  analogWrite(green, g); 
  analogWrite(blue, b);   
}

John Graham-Cumming (JGC), author of The Geek Atlas, wrote in to let us know about a fun conversion he did with a cheap optical mouse:

For a small robot project I’m working on I needed a way to measure the robot’s progress across the floor. There are various possibilities, such as: use stepper motors (expensive and am recycling some old continuous run servos), add an encoder to the wheels (would need to go buy some parts for that), or use the optical sensor for a mouse.

I had a really old PS/2 optical mouse lying around which contains an MCS-12085 optical sensor that has a rather simple serial interface suitable for connection to a microcontroller. Inside there are two separate areas of components. On the right in the picture above is the PS/2 interface chips and four nice extras that I desoldered for later use (three microswitches and a quadrature encoder)…

This is a great example of repurposing something that might otherwise go to a landfill; and to top it off, JGC has posted some code you can use as an Arduino interface to the optical mouse sensor. Read all about his conversion at his blog.

Ben Heck is always thinking up gadgets that make life easier, from completely hands-free luggage to a sensor system for improved cycling safety. His latest mod is meant for those of us who have burnt Ramen a few too many times. His so-called Ben-Stur Remote Control Android app works with a pot-stirring device, freeing users to stray from the kitchen while their meal is cooking. The app works via Bluetooth, and the pot-stirrer consists of an actuator arm, a chip clip, a timing belt and, of course, a wooden spoon. Heck used a Google ADK and an Arduino Uno for the control mechanism that communicates between the app and the stirrer. In the tablet app, users can check their food's temperature and control the speed of the the spoon's stirring. If that whets your appetite, click the source link for more info -- and check out our Maker Faire interview with Mr. Heckendorn himself.

Ben Heck's Android-controlled pot-stirrer does (most of) the cooking for you originally appeared on Engadget on Tue, 22 May 2012 05:54:00 EST. Please see our terms for use of feeds.

From ITP student Justin Lange:

I grew up with my Dad’s songs. Some of my first memories are of him and my Mom singing to me and my siblings. A bad fall last winter left my Dad with a dislocated shoulder and detached nerves. His function in his left arm remains very limited. And he sure can’t play guitar.

I thought,’how about I just build something to allow him to get back to his songs?’ Something of a Luddite at heart, he was a little slow warming up to the idea of an electronic device interfacing between him and an acoustic instrument. Furthermore, he was understandably a bit pessimistic; he said, “Justin, that sounds like a great idea if you’ve got a ten-million dollar research budget behind you, but I just don’t think what you’re talking about is possible”. I said, “let me see what I can do”.

Justin’s device, dubbed the Folkbox, has rows of buttons mounted beneath the neck of the guitar that play chords when depressed. The buttons are hooked up to solenoids that depress the proper strings, allowing the user to play a multitude of different chords.

The interface can be easily rebuilt to allow musicians with other disabilities to play as well. For example, someone who has no use of one hand can have a foot pedal array to play chords.

Justin plans on continuing work with the Folkbox, adding an even larger array of chords it can play, and rebuilding the enclosures in acrylic.

“A Thanks to Chris Anderson, Massimo Banzi, Dale Dougherty and the MAKERS of the new Industrial Revolution.

On March 9 in the Acquario Romano we heard testimonies of people, reality and Italian companies that have never stopped believing in innovation.
We like the stories of those who invest in their future without fear and looking to new technologies.
Just as we love the old craftsmen who know how to reinvent traditions. We know that it takes courage to get involved.
World Wide Rome has shown us that there are opportunities to do business.

No time to lose.

 We want this event would mark the beginning of something new.
We would like the genius of provocation Makers became a model of development.

Let’s get to work.

” [World Wide Rome]

We were there and we show you the key notes of Chris Anderson, and Dale Dougherty.

See the video covered by copyright.

More Photos

Continue reading Step aside Arduino, TinkerForge is the new sheriff in mod-town (video)

Step aside Arduino, TinkerForge is the new sheriff in mod-town (video) originally appeared on Engadget on Fri, 09 Dec 2011 19:35:00 EST. Please see our terms for use of feeds.

I love IKEA and her low cost products.

Last week I found this STRÅLA lamp.

The cost is $4.99, so I bought it.
Lighting the lamp I saw that it ‘s very pretty but also … too soft…

So I thought to modify the LED and add a RGB led.
With simple modify you can obtain a dinamic lamp.
I used an Arduino to do a fast work, but of course it isn’t necessary.
You can use a small microcontroller like a PIC12F675, or a ATTiny.

And this it the result:

How to

Before all, you have to buy a STRÅLA 

Open the package

And disassemble the original LED

As you can see the LED shape isn’t normal, but there is a cone in the center to better spread the light.
So I modify the RGB led to obtain the same effects and I also smoothed the surface.

Connect the wire to the led and reassemble all.

To connect the RGB led I used a strip wire and some pin.

And now you can connect this pin to PWM ports of Arduino.

The black, blue and white wire are the RGB pin of the LED.

The red one is the Anode.

 The sketch

/* IKEA Strala mods

 created 2011
 by Boris Landoni

 This example code is in the public domain.

http://www.open-electronics.org

http://www.futurashop.it

http://blog.elettronicain.it/

 */

#include <EEPROM.h>

int red = 9;    // RED LED connected to PWM pin 3
int green = 10;    // GREEN LED connected to PWM pin 5
int blue = 11;    // BLUE LED connected to PWM pin 6
int r=50; int g=100; int b=150;
int rup; int gup; int bup;
int fader=1;
int inc=10;
void setup()
{
  // start the Ethernet connection and the server:
      Serial.begin(9600);
      Serial.println("Serial READY");
      r = EEPROM.read(1);
      g = EEPROM.read(2);
      b = EEPROM.read(3);
      inc = EEPROM.read(4);
      fader = EEPROM.read(5);
      rgb(r, g, b);
} 

void loop()  { 

  if (fader==1){
    funcfader();
  }

}

void funcfader(){
    Serial.println("fader");
    if (rup==1){r+=1;}
    else{r-=1;}
    if (r>=255){rup=0;}
    if (r<=0){rup=1;}

    if (gup==1){g+=1;}
    else{g-=1;}
    if (g>=255){gup=0;}
    if (g<=0){gup=1;}

    if (bup==1){b+=1;}
    else{b-=1;}
    if (b>=255){bup=0;}
    if (b<=0){bup=1;}

    delay(inc*2);
    rgb(r, g, b);
}

void rgb(int r, int g, int b)
{

  Serial.print("RGB: ");
  Serial.print(r);
  Serial.print(" ");
  Serial.print(g);
  Serial.print(" ");
  Serial.print(b);
  if (r>255) r=255;
  if (g>255) g=255;
  if (b>255) b=255;
  if (r<0) r=0;
  if (g<0) g=0;
  if (b<0) b=0;

  analogWrite(red, r);
  analogWrite(green, g);
  analogWrite(blue, b);
}

Good modding