What is it?

DS1339 RTC Breakout Board is a RTC breakout board from Upbeat Labs based on the DS1339 RTC from Maxim

Innovative Design for plug-in usage with Arduino and Raspberry Pi

The board is designed to be breadboard friendly, and also capable of being plugged in directly to an Arduino or a Raspberry Pi by its innovative dual headers design.

Quality Construction

Environmentally friendly and high-quality ENIG finish and lead-free solder.

It includes 2 mounting holes for attaching to an enclosure if desired.

Square Wave output and 2 Alarms

The DS1339 contains two time of day/date alarms that can raise an interrupt via the SQW/INT pin. It can also generate a square-wave output at the following frequencies:

1Hz 4.096kHz 8.192kHz 32.768kHz

Trickle charger

The DS1339 also includes a trickle charger circuit, that can be enabled via the registers. This breakout board is meant to be used with a coin-cell battery (non-rechargeable) however, if you are interested, let me know and I'll add the ability the incorporate a super-cap or rechargeable battery either here or on another board! If you are adventurous, you can always hook it up to this board by accessing the connections to Vbat and GND!

MCU friendly

DS1339 RTC is tolerant of a wide range of voltages, so you can use it with any 5v or 3.3v MCU without need for level shifting.

Why did you make it?

I worked on an Arduino-based Bluetooth LE (BLE) logger for TI's SensorTag - the Arduino Pro Mini would connect to the Sensor Tag as a BLE master and read the data and log it to an SD card. For that, I needed an RTC that worked with 3.3v, and an alarm to perhaps use with sleep modes to reduce power consumption, and settled on the DS1339 chip as perfect for my needs. I ended up creating a breakout board a while back and writing about it on Instructables (see link below)

I have now decided to bring it up to date with all SMD components and an innovative dual header design that is also breadboard friendly - you can take this and plug it directly into your Arduino or Raspberry Pi and start using it without any breadboard or jumper wires (well, one jumper wire to Pin 2 of Arduino if you want to use its alarm functionality)

It comes with an Arduino library (see GitHub link below), and can also be used with the Raspberry Pi directly by using the rtc-ds1307 module (which has the same register format as the DS1339 for the date/time portion). You can easily find instructions on how to enable an RTC on the Raspberry Pi via many links online.

What makes it special?

• Can directly plug-in to and use with an Arduino or Raspberry Pi with its "two-sets-of-headers" design.
• Breadboard friendly, even with both headers
• Tolerant of a wide range of voltages, including 3.3v and 5v
• Battery backup, so you do not have to worry about resetting the date and time each time you power cycle it.
• Two alarms, which can be used for timed interrupts, which can be used for power management and optimization for low power applications
• As a bonus, DS1339 also has a trickle charger
• Arduino library for easy use
• Use Raspberry Pi, BeagleBone Black and others with the rtc-ds1307 module

Other resources

• RTC BREAKOUT FOR DS1339 ON ARDUINO - LOW COST, BATTERY BACKUP, 2 ALARMS

• ARDUINO BLUETOOTH LE LOGGER FOR TI SENSORTAG (AND OTHERS)