Magnetic field detection



  • Hello everyone...

    i try to build a Anemometer with an AS5040-Chip.... so it would be great to use mysensors with an Anemometer...
    does anyone have a similar project? maybe there are wiring-plans for the as5040 and arduinos?

    thanks for help..


  • Hero Member

    @michlb1982 This site shows how to connect an AS5040 to an Arduino and has a sample sketch: http://reprap.org/wiki/Magnetic_Rotary_Encoder_1.0. The section is towards the bottom called Digital SSI Output. None of the pins used conflict with NRF24 radio usage so it should be relatively simple to MySensor it.

    Cheers
    Al



  • Hello

    thanks for the input...
    well i did it...
    i was able to build an Wind-direction-MYSENSOR... well i'm sure, its a little bit
    awkward and much to complicated but it works quite OK...
    the next step is to build a windspeed - sensor.. with the AS5040..

    here the Arduino nano Code...:

    #include <SPI.h>
    #include <MySensor.h>
    
    const int ledPin = 13; //LED connected to digital pin 13
    const int clockPin = 5; //output to clock
    const int CSnPin = 4; //output to chip select
    const int inputPin = 6; //read AS5040
    
    int inputstream = 0; //one bit read from pin
    long packeddata = 0; //two bytes concatenated from inputstream
    long angle = 0; //holds processed angle value
    long anglemask = 65472; //0x1111111111000000: mask to obtain first 10 digits with position info
    long statusmask = 63; //0x000000000111111; mask to obtain last 6 digits containing status info
    long statusbits; //holds status/error information
    int DECn; //bit holding decreasing magnet field error data
    int INCn; //bit holding increasing magnet field error data
    int OCF; //bit holding startup-valid bit
    int COF; //bit holding cordic DSP processing error data
    int LIN; //bit holding magnet field displacement error data
    int debug = 0; //SET THIS TO 0 TO DISABLE PRINTING OF ERROR CODES
    int shortdelay = 1000; // this is the microseconds of delay in the data clock
    int longdelay =1000; // this is the milliseconds between readings
    #define CHILD_ID_DIR 0
    //#define INTERRUPT inputPin
    MySensor gw;
    MyMessage msgDIR(CHILD_ID_DIR, V_DIRECTION);
    
    void setup()
    {
      gw.begin(NULL, AUTO, true, AUTO);
      Serial.begin(250000);
      pinMode(ledPin, OUTPUT); // visual signal of I/O to chip
      pinMode(clockPin, OUTPUT); // SCK
      pinMode(CSnPin, OUTPUT); // CSn -- has to toggle high and low to signal chip to start data transfer
      pinMode(inputPin, INPUT); // SDA
    
      // Send the Sketch Version Information to the Gateway
      gw.sendSketchInfo("Winddirection", "1.0");
      // Register all sensors to gw (they will be created as child devices)
      gw.present(CHILD_ID_DIR, S_WIND);
    }
    
    void loop()
    {
    // CSn needs to cycle from high to low to initiate transfer. Then clock cycles. As it goes high
    // again, data will appear on sda
      digitalWrite(CSnPin, HIGH); // CSn high
      digitalWrite(clockPin, HIGH); // CLK high
      delay(longdelay);// time between readings
      digitalWrite(ledPin, HIGH); // signal start of transfer with LED
      digitalWrite(CSnPin, LOW); // CSn low: start of transfer
      delayMicroseconds(shortdelay); // delay for chip initialization
      digitalWrite(clockPin, LOW); // CLK goes low: start clocking
      delayMicroseconds(shortdelay); // hold low
      for (int x=0; x <16; x++) // clock signal, 16 transitions, output to clock pin
      {
        digitalWrite(clockPin, HIGH); //clock goes high
        delayMicroseconds(shortdelay); // 
        inputstream =digitalRead(inputPin); // read one bit of data from pin
    //Serial.print(inputstream, DEC);
        packeddata = ((packeddata << 1) + inputstream);// left-shift summing variable, add pin value
        digitalWrite(clockPin, LOW);
        delayMicroseconds(shortdelay); // end of one clock cycle
      }
    // end of entire clock cycle
    //Serial.println(" ");
      digitalWrite(ledPin, LOW); // signal end of transmission
    // lots of diagnostics for verifying bitwise operations
    //Serial.print("packed:");
    //Serial.println(packeddata,DEC);
    //Serial.print("pack bin: ");
    //Serial.println(packeddata,BIN);
      angle = packeddata & anglemask; // mask rightmost 6 digits of packeddata to zero, into angle.
    //Serial.print("mask: ");
    //Serial.println(anglemask, BIN);
    //Serial.print("bin angle:");
    //Serial.println(angle, BIN);
    //Serial.print("angle: ");
    //Serial.println(angle, DEC);
      angle = (angle >> 6); // shift 16-digit angle right 6 digits to form 10-digit value
    //Serial.print("angleshft:");
    //Serial.println(angle, BIN);
    //Serial.print("angledec: ");
    //Serial.println(angle, DEC);
      angle = angle * 0.3515; // angle * (360/1024) == actual degrees
      Serial.print("angle: "); // and, finally, print it.
      Serial.println(angle, DEC);
    //Serial.println("--------------------");
    //Serial.print("raw: "); // this was the prefix for the bit-by-bit diag output inside the loop.
      if (debug)
      {
        statusbits = packeddata & statusmask;
        DECn = statusbits & 2; // goes high if magnet moved away from IC
        INCn = statusbits & 4; // goes high if magnet moved towards IC
        LIN = statusbits & 8; // goes high for linearity alarm
        COF = statusbits & 16; // goes high for cordic overflow: data invalid
        OCF = statusbits & 32; // this is 1 when the chip startup is finished.
        if (DECn && INCn) { Serial.println("magnet moved out of range"); }
        else
        {
          if (DECn) { Serial.println("magnet moved away from chip"); }
          if (INCn) { Serial.println("magnet moved towards chip"); }
        }
        if (LIN) { Serial.println("linearity alarm: magnet misaligned? Data questionable."); }
        if (COF) { Serial.println("cordic overflow: magnet misaligned? Data invalid."); }
      }
      float V_DIRECTION = angle;
      gw.send(msgDIR.set(V_DIRECTION, DEC));
      packeddata = 0; // reset both variables to zero so they don't just accumulate
      angle = 0;
      gw.process();
      //gw.sleep(INTERRUPT,CHANGE);
      gw.sleep(longdelay);
    }
    
    

    the code for FHEM:

    define MYSENSOR_111 MYSENSORS_DEVICE 111
    attr MYSENSOR_111 IODev SerialGate
    attr MYSENSOR_111 alias Windrichtung
    attr MYSENSOR_111 group Sensoren
    attr MYSENSOR_111 mapReading_direction 0 direction
    attr MYSENSOR_111 mapReading_gust 0 gust
    attr MYSENSOR_111 mapReading_wind 0 wind
    attr MYSENSOR_111 mode repeater
    attr MYSENSOR_111 room 03_Umwelt
    attr MYSENSOR_111 stateFormat {sprintf("%.0f",ReadingsVal("MYSENSOR_111","direction",0))."°"}
    

    a curcuit will follow in the next days...

    greets..
    Mike



  • here some pics
    Foto 06.12.15, 13 06 18.jpg Foto 06.12.15, 13 06 27.jpg Foto 06.12.15, 13 06 08.jpg Foto 06.12.15, 13 06 00.jpg



  • well, the promised curcuit...Windrichtung-AS5040-Mysensor.pdf Windrichtung_Steckplatine.jpg Windrichtung.fzz


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