Two B or not 2 Bs?
Figure 1. A Model B+ next to a Model B.
There are some subtle changes including the repositioning of some connectors, the replacement of linear power supplies with switch mode types, the replacement of the SD connector with a microSD connector, the removal of the RCA video connector and associated components, a larger expansion port and some usable mounting screw holes.
Out of the box the Raspberry Pis do not have a continuous Real Time Clock capability.This can be addressed in many ways. One way is having the RPi connected to a network and obtaining its time from a Network Time Server. Other methods include using a direct connection to a time source such as a GPS module or Battery Backed RTC IC. I2C bus RTCs ICs such as the PCF8563, PCF2127 and DS1307 have been successfully integrated.
The DS1307 and DS1307+ are older ICs operating from 5V and the PCF2127 and PCF8563 have a lower VDD(min) and can operate at the RPi's VDD.
Please leave a comment if you want me to attempt interfacing an I2C RTC to the Raspberry Pi.
Investigating the options.
Provided that it is located in an area that can receive GPS signals, I can make a portable wireless time server using a GPS module, network module and microcontroller (with of course supporting power).
Using a Raspberry Pi for the microcontroller could be overkill. Depending upon the network module used it could be done with a much lower cost device (or even the network module itself if it has an inbuilt microcontroller).
An RPiSoC perhaps?
Please leave a comment if you want me to attempt to making one.
