Arduino and Mango Step by step working example

[JointTech]

1. Buy or make a Arduino

2. Download the latest Arduino software I'm using 0020. http://arduino.cc/en/Main/Software

3. If you are using Arduino Duemilanove or a similar board that runs off USB you’ll have to install the USB drivers. You can find them in the Arduino folder you just downloaded.

4. plug in a TMP36 temp sensor as shown here: http://tinyurl.com/plbx38
   Plug it into Analog port 3 instead of 0 as shown in the link.

5. Grab the modbus library from http://www.tucsni.nl/jee/ModbusSlave.zip
   you should check his site http://www.tucsni.nl/jee/ he actually says to use the new version here: http://sites.google.com/site/jpmzometa/arduino-mbrt/arduino-modbus-slave
   but I havent tested it.

6. Unzip modbusslave.zip to your_arduino_install\libraries\ModBusSlave

7. open the arduino IDE

8. Paste the following code:

#include <ModbusSlave.h>

//TMP36 Pin Variables
int temperaturePin = 3; //the analog pin the TMP36's Vout (sense) pin is connected to
                        //the resolution is 10 mV / degree centigrade 
                        //(500 mV offset) to make negative temperatures an option
int temptest = 1 ;                        
//Arduino sketch example with 2 holding regs:
void setup()
{
	  /* Modbus setup example, the master must use the same COM parameters */
	  /* 115200 bps, 8N1, two-device network */
//	  regs[MB_REG0]=153;
//	  regs[MB_REG1]=456;

	  init_mb_slave(115200, 'n', 0);
}


void loop()
{
    /* This is all for the Modbus slave */
    start_mb_slave(MB_SLAVE, regs, MB_REGS);

    /* your code goes here */
 float temperature = getVoltage(temperaturePin);  //getting the voltage reading from the temperature sensor
 temperature = (((temperature - .5) * 100)*1.8) + 32;          //converting from 10 mv per degree wit 500 mV offset
                                                  //to degrees ((volatge - 500mV) times 100)
// Serial.println(temperature);    
// Serial.println(regs[MB_REG0]);    //printing the result
// delay(100);       
temptest = (temperature);
regs[MB_REG0]=temptest;


    /* handle write event */
    if (written.num_regs) {
   ///     ....
	  written.num_regs=0;
    }
}  

/*
 * getVoltage() - returns the voltage on the analog input defined by
 * pin
 */
float getVoltage(int pin){
return (analogRead(pin) * .004882814); //converting from a 0 to 1024 digital range
                                        // to 0 to 5 volts (each 1 reading equals ~ 5 millivolts
}

9. upload the code to your Arduino.

10. Install Mango

11. Create a new data source.
    [url=http://postimage.org/image/1kmj3h7pg/]

12. Create a new datapoint
    [url=http://postimage.org/image/1syvr8io4/]

13. you should now be seeing the current temperature updating every 5 seconds on your datapoint.
    You can breathe hard on your tmp36 to see the temp go up in mango.

have fun.
hope this helps somebody as it took me about 2 days of scouring the net to make it finally work.

[mlohbihler]

Nice. Thanks.

[jose francisco]

Hello.

I'm trying to compile the sketch buy i get an error in "init_mb_slave(...)" not declared function.

I think that the library i've got is newer because in new examples the configuration is done in this way:

mbs.configure(SLAVE,BAUD,PARITY,TXENPIN);

Can you comment this issue?
thanks

[JointTech]

I would use the library here: http://www.tucsni.nl/jee/ModbusSlave.zip
other than that I have no idea. probably question better for the arduino forums as well.

[jose francisco]

Sketch for new library from http://sites.google.com/site/jpmzometa/arduino-mbrt/arduino-modbus-slave

With this code you can:
-See the status of pin 2 in mango (MB_REG0)
-set the status of pin 13 with mango (MB_CTRL)

use offset 0,1,... in mango to use MB_REG0, MB_CTRL, MB_TIME,...

#include <ModbusSlave.h>

/* First step MBS: create an instance */
ModbusSlave mbs;

/* slave registers */
enum {        
        MB_REG0,
        MB_CTRL,        /* Led control on, off or blink */
        MB_TIME,        /* blink time in milliseconds */
        MB_CNT,        /* count the number of blinks */
        MB_REGS	 	/* total number of registers on slave */
};

int asdf=1;
int regs[MB_REGS];
int ledPin = 13;


void setup() 
{
        
/* the Modbus slave configuration parameters */
const unsigned char SLAVE = 1;
const long BAUD = 9600;
const char PARITY = 'n';
const char TXENPIN = 1;

       /* Second step MBS: configure */
      mbs.configure(SLAVE,BAUD,PARITY,TXENPIN);

        pinMode(ledPin, OUTPUT);
        pinMode(2,INPUT);
}

void loop()
{


       asdf=digitalRead(2);
      regs[MB_REG0]=asdf;


  /* Third and las step MBS: update in loop*/
       mbs.update(regs, MB_REGS);

   if(regs[MB_CTRL]==1)
     digitalWrite(ledPin,1);
     else
     digitalWrite(ledPin,0);

}

[JointTech]

Nice I was struggling with setting values. Ill have to give this a try.

[relristein]

Hi,

I have a one question. I use the modbus serial for comunication. It is script:

#include <ModbusSlave.h>
/* First step MBS: create an instance /
ModbusSlave mbs;
/ slave registers */
enum {

MB_CTRL, /* Led control on, off or blink /
MB_TIME, / blink time in milliseconds /
MB_CNT, / count the number of blinks /
MB_REGS / total number of registers on slave */

};

int regs[MB_REGS];
int ledPin = 13;

void setup()
{

/* the Modbus slave configuration parameters /
const unsigned char SLAVE = 1;
const long BAUD = 9600;
const char PARITY = 'n';
const char TXENPIN = 1;
/ Second step MBS: configure */
mbs.configure(SLAVE,BAUD,PARITY,TXENPIN);
pinMode(ledPin, OUTPUT);

}

void loop()

{

/* Third and las step MBS: update in loop*/

mbs.update(regs, MB_REGS);

if(regs[MB_CTRL]==1)

{

digitalWrite(ledPin,1);

}

else{

digitalWrite(ledPin,0);

}

}

---

But i want a blink effect in led and i modified the script:

if(regs[MB_CTRL]==1)
{
digitalWrite(ledPin,1);
delay(3000);
digitalWrite(ledPin,0);
delay(3000);
}
else{
digitalWrite(ledPin,0);
}
}

Well, when i set the bit 1, the led blink but it don't enter in the else.

Anyone had the same problem with supervisory and script?

tank's

*sorry, my english is very weak.