Best posts made by ThomasDr

Hello,

I develop for some time sensors for this purpose.
And I think now I have a variant found.
The technology is nothing special.
I simple use a MMA8452 connect to a Mysensors Note.
The evaluation does the Sketch.
Here my Sketch:

/******************************************************************************
MMA8452Q_Basic.ino
SFE_MMA8452Q Library Basic Example Sketch
Jim Lindblom @ SparkFun Electronics
Original Creation Date: June 3, 2014
https://github.com/sparkfun/MMA8452_Accelerometer

This sketch uses the SparkFun_MMA8452Q library to initialize the
accelerometer, and stream values from it.

Development environment specifics:
	IDE: Arduino 1.0.5
	Hardware Platform: Arduino Uno
	
	**Updated for Arduino 1.6.4 5/2015**

This code is beerware; if you see me (or any other SparkFun employee) at the
local, and you've found our code helpful, please buy us a round!

Distributed as-is; no warranty is given.
******************************************************************************/
#include <Wire.h> // Must include Wire library for I2C
#include <SparkFun_MMA8452Q.h> // Includes the SFE_MMA8452Q library
#include <MySensor.h>  
#include <Vcc.h>

const float VccMin   = 0.0;           // Minimum expected Vcc level, in Volts.
const float VccMax   = 5.5;           // Maximum expected Vcc level, in Volts.
const float VccCorrection = 5.0/5.0;  // Measured Vcc by multimeter divided by reported Vcc

unsigned int countr = 0;
float peakMax0 = -1000.0;
float peakMax1 = -1000.0;
float peakMax2 = -1000.0;
unsigned long startMillis = 0;
Vcc vcc(VccCorrection);

#define CHILD_ID_BATT 0
#define CHILD_ID_MAXX 1
#define CHILD_ID_MAXY 2
#define CHILD_ID_MAXZ 3

MySensor gw;
MyMessage battmsg(CHILD_ID_BATT, V_VOLTAGE);
MyMessage maxxmsg(CHILD_ID_MAXX, V_LEVEL);
MyMessage maxymsg(CHILD_ID_MAXY, V_LEVEL);
MyMessage maxzmsg(CHILD_ID_MAXZ, V_LEVEL);


MMA8452Q accel;

void setup()
{
  Serial.begin(115200);
  accel.init(SCALE_2G, ODR_800);
  gw.begin(NULL, AUTO, true);

  // Send the sketch version information to the gateway and Controller
  gw.sendSketchInfo("MMA8452", "1.0");

  // Register all sensors to gateway (they will be created as child devices)
  gw.present(CHILD_ID_BATT, S_POWER);
  gw.present(CHILD_ID_MAXX, S_VIBRATION);
  gw.present(CHILD_ID_MAXY, S_VIBRATION);
  gw.present(CHILD_ID_MAXZ, S_VIBRATION);
}

void loop()
{     
       countr = 0;
       float peakToPeak0 = 0.0;   // peak-to-peak level
       float peakToPeak1 = 0.0;   // peak-to-peak level
       float peakToPeak2 = 0.0;   // peak-to-peak level
       
       float signalMax0 = -100.0000;
       float signalMin0 = 100.0000;
       float signalMax1 = -100.0;
       float signalMin1 = 100.0;
       float signalMax2 = -100.0;
       float signalMin2 = 100.0;
     
       
       while (countr < 20)
           {
            gw.process();
          if (accel.available())
             {
              accel.read();
              delay(2);
              double accxx = accel.cx;
              double accyy = accel.cy;
              double acczz = accel.cz;
                 //--------------------------------------------------
                 if (accxx > signalMax0)
                  {
                     signalMax0 = accxx;  // save just the max levels
                  }
                 if (accxx < signalMin0)
                  {
                     signalMin0 = accxx;  // save just the min levels
                  }
                 //--------------------------------------------------
                 if (accyy > signalMax1)
                  {
                     signalMax1 = accyy;  // save just the max levels
                  }
                  
                 if (accyy < signalMin1)
                  {
                     signalMin1 = accyy;  // save just the min levels
                  }
                 //-------------------------------------------------
                 if (acczz > signalMax2)
                  {
                    signalMax2 = acczz;  // save just the max levels
                  }
                  
                 if (acczz < signalMin2)
                  {
                    signalMin2 = acczz;  // save just the min levels
                  }
                  countr = countr + 1;
             }
         }
             //------------------------------------------------------
             peakToPeak0 = signalMax0 - signalMin0;
             peakToPeak1 = signalMax1 - signalMin1;
             peakToPeak2 = signalMax2 - signalMin2;
             //-----------------------------------------------------
             //------------------------------------------------------
             if (peakToPeak0 > peakMax0)
             {
                peakMax0 = peakToPeak0;  // save just the max levels
             }
             if (peakToPeak1 > peakMax1)
             {
                peakMax1 = peakToPeak1;  // save just the max levels
             }
             if (peakToPeak2 > peakMax2)
             {
                peakMax2 = peakToPeak2;  // save just the max levels
             }
             //-----------------------------------------------------
             
 if (millis() > startMillis)
 {
 float v = vcc.Read_Volts();
  gw.send(battmsg.set(v,2));
  gw.send(maxxmsg.set(peakMax0,4));
  gw.send(maxymsg.set(peakMax1,4));
  gw.send(maxzmsg.set(peakMax2,4));
  
 peakMax0 = -1.0;
 peakMax1 = -1.0;
 peakMax2 = -1.0;
 startMillis= millis() + 15000;
 }
 
}

Improvements and suggestions are welcome.

regards
Thomas

Hello,

I think I have found the error.
I use a 15sec. loop in the sketch and i thing a intern watchdog reset the Node.

regards
Thomas

Hello,

I think you were right, I had tried it without a cap, it worked, but it works better with cap.

regards
Thomas