DS3231 Side Mount

Hobbyists and makers frequently use a real-time clock module in their designs. One very common board is a DS3231 mounted on a board with a coin-cell holder, EEPROM, and the necessary resistors/power LEDs.  I found myself in a situation where I needed to conserve main board real estate, but mounting the DS3231 vertically (which is really easy to do) would not fit in my enclosure. A horizontal mount still saves quite a bit of board surface area, but is a little difficult to achieve. This part allows the module to be easily and securely glued to my circuit board. The module fits snugly into the mount, but I am adding a dot or two of superglue between the board and the mount for added security.

Printed in PETG, default settings on an MKS4. Designed in SolidWorks Maker. I suggest you print several copies because they can be a little hard to remove from the print surface.

Update 31 May 2026. I found that some modules may fit imperfectly if the manufacturer did not center the coin cell holder exactly. Version 2 has a cutout to accommodate this problem if it is encountered.

Update 9 July 2026. I ultimately abandoned the DS3231 board, as it was not fit for purpose. I substituted a SparkFun RTC board called the RV1803. It's not commonly used, but I've posted the STL for that board as well. It mounts on the Qwiic connector side, with the shorter slot on the side with the surface mount resistors. It's pretty obvious.