BQ32002: connecting with Arduino

Hi Dhanya,

It is not clear what the issue is. Can you share the schematic? What are the VCC and Vback volatages?

The registers are not identical between BQ32002 and the competitor device. Addresses 0x00 to 0x06 are similar with differences in the location of the century data. Registers 0x07 and beyond do not match. I recommend to review the register settings for correctness.

Additionally, need to confirm that the oscillator is functioning

Kind regards,
Lane

Hi Lane,

Thank you for your reply.

I have given Vcc as 3.3V.I am not giving Vback since power from Vcc for testing.

Lane Boyd said:

Additionally, need to confirm that the oscillator is functioning

How to check whether the oscillator is working?

I can able to write time and date to RTC and the same time i can read from RTC.So i think oscillator not working.Its not acting as clock

I am sending the code also.

Regrads,

Dhanya

#include "Wire.h"
#define BQ32002_ADDRESS 0x68
// Convert normal decimal numbers to binary coded decimal


byte decToBcd(byte val)
{
  return( (val/10*16) + (val%10) );
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val)
{
  return( (val/16*10) + (val%16) );
}
void setup()
{
  Wire.begin();

  Serial.begin(9600);
  // set the initial time here:
  // DS3231 seconds, minutes, hours, day, date, month, year
  setDS3231time(30,35,11,3,12,1,20);
}
void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte
dayOfMonth, byte month, byte year)
{
  // sets time and date data to DS3231
  Wire.beginTransmission(BQ32002);
  Wire.write(0); // set next input to start at the seconds register
  Wire.write(decToBcd(second)); // set seconds
  Wire.write(decToBcd(minute)); // set minutes
  Wire.write(decToBcd(hour)); // set hours
  Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday)
  Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31)
  Wire.write(decToBcd(month)); // set month
  Wire.write(decToBcd(year)); // set year (0 to 99)
  Wire.endTransmission();
}
void readDS3231time(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
  Wire.beginTransmission(BQ32002);
  Wire.write(0); // set BQ32002 register pointer to 00h
  Wire.endTransmission();
  Wire.requestFrom(BQ32002, 7);
  // request seven bytes of data from BQ32002 starting from register 00h
  *second = bcdToDec(Wire.read() & 0x7f);
  *minute = bcdToDec(Wire.read());
  *hour = bcdToDec(Wire.read() & 0x3f);
  *dayOfWeek = bcdToDec(Wire.read());
  *dayOfMonth = bcdToDec(Wire.read());
  *month = bcdToDec(Wire.read());
  *year = bcdToDec(Wire.read());
}
void displayTime()
{
  byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
  // retrieve data from DS3231
  readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month,
  &year);
  // send it to the serial monitor
  Serial.print(hour, DEC);
  // convert the byte variable to a decimal number when displayed
  
  Serial.print(":");
  
  if (minute<10)
  {
    Serial.print("0");
  }
  Serial.print(minute, DEC);
  
  Serial.print(":");
  
  if (second<10)
  {
    Serial.print("0");
  }
  Serial.print(second, DEC);
  
  Serial.print(" ");
  
  Serial.print(dayOfMonth, DEC);
  
  Serial.print("/");
  Serial.print(month, DEC);
  Serial.print("/");
  Serial.print(year, DEC);
  Serial.print(" Day of week: ");
  switch(dayOfWeek){
  case 1:
    Serial.println("Sunday");
    break;
  case 2:
    Serial.println("Monday");
    break;
  case 3:
    Serial.println("Tuesday");
    break;
  case 4:
    Serial.println("Wednesday");
    break;
  case 5:
    Serial.println("Thursday");
    break;
  case 6:
    Serial.println("Friday");
    break;
  case 7:
    Serial.println("Saturday");
    break;
  }
}
void loop()
{
  displayTime(); // display the real-time clock data on the Serial Monitor,
  delay(1000); // every second
}

Hi Dhanya,

Thanks for the info. To check if the oscillator is functioning, read back the OF bit (register 0x01 bit 7). See the description under table 5 on page 13 for more information.

Note that the OF flag is always set during power-on, and must be cleared during after initialization in order to detect subsequent oscillator fail events

Kind regards,
Lane