![Yuehuam Clock Module DS3231 RTC Board Real Time Clock Module for Arduino Raspberry Pi]({"https://m.media-amazon.com/images/I/5116a-q5UiS._AC_SS130_.jpg":[130,130],"https://m.media-amazon.com/images/I/5116a-q5UiS._AC_SS260_.jpg":[260,260],"https://m.media-amazon.com/images/I/5116a-q5UiS._AC_SS390_.jpg":[390,390]})
![SunFounder DS18B20 Temperature Sensor Module Compatible with Arduino and Raspberry Pi]({"https://m.media-amazon.com/images/I/61hb6EtRtnL._AC_SS130_.jpg":[130,130],"https://m.media-amazon.com/images/I/61hb6EtRtnL._AC_SS260_.jpg":[260,260],"https://m.media-amazon.com/images/I/61hb6EtRtnL._AC_SS390_.jpg":[390,390]})
First the good news -
With this module installed my Raspberry Pi boots up with accurate time without being connected to the net.
This little RTC module is TINY, but is super accurate compared to most PC clocks, thanks to it's use of the DS3231 RTC chip (mine keeps time within a few seconds per month)
Now the bad news -
I would have rated the SunFounder DS3231 RTC Real Time Clock Module a solid 5 out of 5, but the software support for installation of the module on the Raspberry Pi could be a bit better.
The official Raspbian O.S. from the Raspberry Pi Foundation web site DOES NOT have support for a hardware clock of any kind enabled by default (because the PI hardware doesn't have a built in RTC chip)
So you need to update your system configuration to enable the clock - and unfortunately this module doesn't come with a simple one-click type installer script.
The seller does provide a link to a set of installation instructions, and they did provide me with enough information to get the clock module working, but it wasn't as easy as it could have been.
To install from the provided instructions you have to understand how to edit your system files and run several commands from a terminal as root.
To make matters worse, the script examples in the DOCX file that the seller gives the link to have a few typos that are just enough to keep the clock module from working unless you understand enough about bash scripts to see the errors and fix them when entering the changes to your system files.
For example in the how-to document provide in the link we see the command -
forbus in $(ls -d /sys/bus/i2c/devices/i2c-*);
Which SHOULD read -
for bus in $(ls -d /sys/bus/i2c/devices/i2c-*);
Note that all important SPACE between the words 'for' and 'bus'. If you understand bash scripting this is obvious because this appears to be a for/next construct, and sure enough, the script later uses the value $bus/ which is obviously a reference to the previously assigned for loop index value 'bus' from the 'for bus' line but if you don't savvy bash, and just cut and past the example - THE CLOCK WILL NOT WORK.
Also the installation instructions document is provide as a crappy docx format instead of as a PDF, so you will need something like MS Office or Open/Lebra Office installed just to read it.
If you are enough of a Linux Geek to get past these minor bumps though, then - THE CLOCK WORKS GREAT.
IF I MIGHT MAKE A SUGGESTION TO THE SELLER...
Installing this clock SHOULD be as simple as 1, 2, 3 and SHOULD work something like this -
1) User should download the file InstallClock.zip and unzip it to extract InstallClock.sh
(where "InstallClock.sh" is the [currently missing] clock installer shell script)
2) User makes the installer script executable by opening the folder where it
was unzipped, then right click the file InstallClock.sh and select "Properties"
-from the dropdown menu, then in the "File Properties" window change the
checkmark for the setting "Make File Executable" so it is checked
- and close the file properties.
3) Now double click the file InstallClock.sh and in the pop-up window select "Execute in Terminal"
and the shell script install your DS3231 RTC Real Time Clock Module, which will become active
the next time you boot your Raspberry Pi.
This alternative would be VERY simple (anyone who has run windows has done similar)...
Again, that's how it SHOULD WORK but unfortunately this is NOT how it does work, at least
not at the present BECAUSE THERE IS NO INSTALLER SCRIPT PROVIDED.
So, I would encourage the seller to repackage the existing installation package as a single
zip file containing both a PDF document that shows how to physically mount the module
*PLUS* the convenient ONE-CLICK "InstallClock.sh" installation script that I mentioned
in the hypothetical example above.
I know that it would not be too hard to do this because I hacked together an install script
for my own use - just so I wouldn't have to manually re-edit all those system files every
time I re-install the Pi's Raspbian O.S. - so I know it CAN be done, and hope that the seller
will consider providing such a script, because it would make his product about 500 times
easier to install.
| Brand | SunFounder |
|---|---|
| Item Weight | 0.32 ounces |
| Product Dimensions | 6 x 4.5 x 0.1 inches |
| Item Dimensions LxWxH | 6 x 4.5 x 0.1 inches |
| Manufacturer | SunFounder |
| ASIN | B00HF4NUSS |
| Is Discontinued By Manufacturer | No |
| Date First Available | December 19, 2013 |
