The portable locomotion activity monitor (pLAM) is a DIY setup to automate small animal circadian activity monitoring over any length of time under variable light conditions. It uses a Raspberry Pi (single board computer) and open source motion capture tools to monitor and detect insect motion in a small chamber. Unlike other software, we provide a pre-configured version of the software on a disk image of an SD card that can be cloned and be used to run the pLAM on the users raspberry Pi, although hardware assembly is still required. The OSF site hosts the disk images and the tutorials and the github page has the updated code wrappers.