RTC Cape

Descriptions
The RTC Cape provides time tracking capability for the BeagleBone Black even when the power is lost. This cape features the DS1338 I2C-based real-time clock/calendar and a holder for a coin battery type CR2032. Setup, reading, and setting up time is easy with the provided device tree overlay.

Revision A1
Initial release of RTC Cape.

Software Support & Compatibility

 * All revisions are compatible with BeagleBone and BeagleBone Black using 3.8 kernel.


 * Latest software for BeagleBone Black can be downloaded here.

Getting Started
The instructions below are performed on Debian release 2014-05-14 (Linux beaglebone 3.8.13-bone50 #1 SMP Tue May 13 13:24:52 UTC 2014 armv7l GNU/Linux).
 * Connect your BeagleBone Black to the internet, log in as root, download the device tree files and extract them to /lib/firmware of your BBB:


 * Load the device tree overlay for your RTC Cape:


 * Check to ensure the overlay is loaded. In the messages below, the DS1338 is registered as rtc1:


 * Read the time from the RTC chip. It should look like something below since the time has not been set:


 * Update the system time of the BeagleBone Black (internet connection required) and write that to the RTC chip using hwclock command:


 * Read the time again. This time it should have been updated.

Helpful Links

 * DS1338 Datasheet
 * Capemgr wiki
 * Device Tree Usage

Specifications
Followings are some specifications of the RTC Cape:

Distributors
Please visit Where To Buy for a list of distributors who carry BeagleBoardToys' capes.

RTC Cape Revision A1
To download all files at once please click here
 * Bill of Materials
 * Manufacturing Files
 * Schematic (PDF)
 * Schematic (EAGLE) (Right click and save as...)
 * PCB (EAGLE) (Right click and save as...)

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