Problem with I2C RTC DS1307 Module

[danigom 2]

Hello to everyone, I am new with MSP430 Launchpad and Energ

Edited September 22, 2013 by bluehash
[ADMIN] - Please upload pics to 43oh.com next time

[chicken 630]

Looks like the RTCLib is using native AVR code, i.e. it needs some fixing to be portable beyond Arduino.

 

Are you using the Adafruit library?

https://github.com/adafruit/RTClib

[chicken 630]

Taking a quick look at the code, you'll need to change at least the following:

 

Remove this line, MSP430 can access data stored in ROM just fine without.

5: #include <avr/pgmspace.h>

 

Related to this, remove PROGMEM directive here: (you might prefix the line with static)

 

23: const uint8_t daysInMonth [] PROGMEM = { 31,28,31,30,31,30,31,31,30,31,30,31 };

and access to the array has to be rewritten, original:

 

31: days += pgm_read_byte(daysInMonth + i - 1);
..
62: uint8_t daysPerMonth = pgm_read_byte(daysInMonth + m - 1);

changed:

 

31: days += daysInMonth[i - 1];
..
62: uint8_t daysPerMonth = daysInMonth[m - 1];

 

And finally, replace this section with #include "Energia.h"

 

13: #if (ARDUINO >= 100)
14:  #include <Arduino.h> // capital A so it is error prone on case-sensitive filesystems
15: #else
16:  #include <WProgram.h>
17: #endif

[danigom 2]

Taking a quick look at the code, you'll need to change at least the following:

 

Remove this line, MSP430 can access data stored in ROM just fine without.

 

5: #include

 

 

Related to this, remove PROGMEM directive here: (you might prefix the line with static)

23: const uint8_t daysInMonth [] PROGMEM = { 31,28,31,30,31,30,31,31,30,31,30,31 };

 

and access to the array has to be rewritten, original:

31: days += pgm_read_byte(daysInMonth + i - 1);

..

62: uint8_t daysPerMonth = pgm_read_byte(daysInMonth + m - 1);

 

changed:

31: days += daysInMonth[i - 1];

..

62: uint8_t daysPerMonth = daysInMonth[m - 1];

 

 

And finally, replace this section with #include "Energia.h"

13: #if (ARDUINO >= 100)

14: #include // capital A so it is error prone on case-sensitive filesystems

15: #else

16: #include

17: #endif

 

First of all thank you for taking your time on it. Could you tell me how can I modify the library with energia IDE? (.cpp or .h file?)

 

Thank you!

[cde 334]

First of all thank you for taking your time on it. Could you tell me how can I modify the library with energia IDE? (.cpp or .h file?)

 

Thank you!

Simply open the RTClib.cpp or RTClib.h file like you would any other file. I suggest make a backup first. The files should be in (specifically in your case) 

D:\Desktop\Energ

[danigom 2]

Looks like the RTCLib is using native AVR code, i.e. it needs some fixing to be portable beyond Arduino.

 

Are you using the Adafruit library?

https://github.com/adafruit/RTClib

Yes, I'm using it!

[danigom 2]

 

Taking a quick look at the code, you'll need to change at least the following:

 

Remove this line, MSP430 can access data stored in ROM just fine without.

5: #include <avr/pgmspace.h>

Related to this, remove PROGMEM directive here: (you might prefix the line with static)

23: const uint8_t daysInMonth [] PROGMEM = { 31,28,31,30,31,30,31,31,30,31,30,31 };

and access to the array has to be rewritten, original:

31: days += pgm_read_byte(daysInMonth + i - 1);
..
62: uint8_t daysPerMonth = pgm_read_byte(daysInMonth + m - 1);

changed:

31: days += daysInMonth[i - 1];
..
62: uint8_t daysPerMonth = daysInMonth[m - 1];

And finally, replace this section with #include "Energia.h"

13: #if (ARDUINO >= 100)
14:  #include <Arduino.h> // capital A so it is error prone on case-sensitive filesystems
15: #else
16:  #include <WProgram.h>
17: #endif

I'm sorry, I could't fix it with these modifications. Could anyone tell me another library to work with this module?

[chicken 630]

Does it compile?

 

If not, what's the error?

[Rei Vilo 695]

The specification sheet of the DS1307 says the supply voltage is min=4.5B typical=5V max=5.5V.

 

How do you make the connection to the LaunchPad pins which are 3.3V-based?

 

Two risks:

• data from the DS1307 may overload and fry the pins of the LaunchPad 
• signal HIGH from the LaunchPad isn't high enough for the DS1307 and is considered as LOW by the DS1307

I suggest using the NXP PCF2129A instead. The PCF2129A operates at 3.3V, embeds the quartz crystal and requires no passive components.

[danigom 2]

The specification sheet of the DS1307 says the supply voltage is min=4.5B typical=5V max=5.5V.

 

How do you make the connection to the LaunchPad pins which are 3.3V-based?

 

Two risks:

• data from the DS1307 may overload and fry the pins of the LaunchPad 
•  
• signal HIGH from the LaunchPad isn't high enough for the DS1307 and is considered as LOW by the DS1307
•  

I suggest using the NXP PCF2129A instead. The PCF2129A operates at 3.3V, embeds the quartz crystal and requires no passive components.

 

I supply the RTC module with 5V directly from the USB Port although the connection with the Launchpad is 3.3V. I've attached two pictures so that you can see the connections:

 

 

 

I think that the problem could be with the I2C communication, the HIGH for Launchpad is 3.3V and could be considered as LOW by the DS1307 ???? 

[danigom 2]

Does it compile?

 

If not, what's the error?

 

Yes, it compiles without any error message, but the Serial Port shows nothing. 

 

[danigom 2]

I have done some modifications:  If I supply the RTC DS1307 Module with 3.6V from the Launchpad instead of 5V it works, but not correctly: 

 

I get this: 

 

 

The code is: 

// Date and time functions using a DS1307 RTC connected via I2C and Wire lib

#include <Wire.h>
#include "RTClib.h"

RTC_DS1307 RTC;

void setup () {
    Serial.begin(9600);
    Wire.begin();
    RTC.begin();

  if (! RTC.isrunning()) {
    Serial.println("RTC is NOT running!");
    // following line sets the RTC to the date & time this sketch was compiled
    RTC.adjust(DateTime(__DATE__, __TIME__));
  }
}

void loop () {
    DateTime now = RTC.now();
    
    Serial.print("Date: ");    
    Serial.print(now.year(), DEC);
    Serial.print('/');
    Serial.print(now.month(), DEC);
    Serial.print('/');
    Serial.println(now.day(), DEC);
    Serial.print("Time: ");  
    Serial.print(now.hour(), DEC);
    Serial.print(':');
    Serial.print(now.minute(), DEC);
    Serial.print(':');
    Serial.print(now.second(), DEC);
    Serial.println();
    Serial.println();
    delay(3000);
}

 

[cde 334]

Does that module have builtin i2c pullup resistors?

[chicken 630]

When you press Reset on the LaunchPad, does it display "RTC is not running!"?

 

Also, for better debugging you can try to insert the following lines into your loop:

Wire.beginTransmission(0x68);
Wire.write((uint8_t) 0);
Wire.endTransmission();
 
Wire.requestFrom(0x68, 7);
uint8_t ss = Wire.read();
uint8_t mm = Wire.read();
uint8_t hh = Wire.read();
Wire.read();
uint8_t d = Wire.read();
uint8_t m = Wire.read();
uint8_t y = Wire.read();
 
Serial.print("raw RTC data ");
Serial.print(ss);
Serial.print("\t");
Serial.print(mm);
Serial.print("\t");
Serial.print(hh);
Serial.print("\t");
Serial.print(d);
Serial.print("\t");
Serial.print(m);
Serial.print("\t");
Serial.println(y);

And while looking at the code, I noticed a pretty unusual hack that actually might be a freak cause of the issue:

int i = 0; //The new wire library needs to take an int when you are sending for the zero register
..
Wire.beginTransmission(0x68);
Wire.write(i);
Wire.endTransmission();

 

That's one ugly way to do a cast. AVR being an 8bit might interpret the int as 8 bit, MSP430 will treat it as 16bit. This might confuse the RTC. Try replacing the first line (line 19 in the original library) with

 

uint8_t i = 0;

[danigom 2]

Does that module have builtin i2c pullup resistors?

 

This is the schematics of the module: 

 

 

 

Thank you for taking your time.