In this article we will show how to interface the FOX board to a Real Time Clock chip from Dallas/Maxim type DS through the I2C protocol. DS, DS Datasheet, DS Trickle Charge Timekeeping Chip, buy DS Photograph. DS Dallas Semiconductor IC. Real Time Clock - DS This is a VERY simple tutorial on how to use the DS Real Time Clock with an Arduino, or Versilino, board. I will walk you.

The playground is a publicly-editable wiki about Arduino. Board Setup and Configuration.

Arduino Playground - DS

Arduino on other Chips. Sources for Electronic Parts. Related Hardware and Initiatives. Cheap modules with the DS and DS have often problems with the crystal and the voltage.

They often don’t work very well. You are strongly advised to use a DSwhich is very reliable and accurate and needs only a battery to run the crystal is inside the DS This circuit has pull-down resistors which are an extra, in many cases they are not needed.

The page at maxim for the DS with all information and datasheet: The DS can be easily connected to the Arduino.

DS Datasheet(PDF) - Dallas Semiconductor

The Vcc1 is for a battery or a rechargable battery or a supercap. A crystal of The three pins for the interface should avoid to use the internal pull-up resistors of the Arduino. Some schematics on the internet have pull-up resistors on the three interface lines.

Other schematics use two 22pF with the crystal. That is also wrong.

See the datasheet for full specifications and a circuit. The most used name is “3-wire interface”. During reading, the clock could rollover. That would result in bad clock data. To prevent that, the DS has a buffer to store the clock data. That buffer can be read in a single communication session, called a “burst” mode. The Year data of the DS is only two digits The Year ‘0’ isand not or It has a Leap-Year compensation from up to for a value of The chip has 31 bytes of ram.

Add a Dallas DS1302 I2C Real Time Clock

The data in this ram will get lost if the Arduino is off, and the battery or supercap gets empty. The standard date and time functions like: At this moment there is no official library for date and time functions for the Arduino.

The most used date and time functions for the Arduino: For the name of a month, this page contains many languages: The code below contains basic interface functions for the DS Use it with Arduino 1.

For more info pleae look at this Forum Post. This is a cheap module with the DS If a byte is read, the addres is written first. The last clock pulse of the address using the rising edge is also the first clock pulse of the data to read using the falling edge.

So the code has to detect that condition to prevent an extra clock pulse. I was noted that the code could be improved. That way the check for the 7th bit is not needed, since the line is always released.