The BOM on [Jeremy S Cook]’s build is extremely short – just a PIR sensor and an optoisolator, with a battery, a plug for the camera’s remote jack, and a 3D-printed bracket. The PIR sensor ...
As an example, [Circuit Valley] has an IKEA Vallhorn motion sensor for a teardown ... op-amp for signal conditioning the PIR output, but the pinout seems not to support it and from here we ...