Abstract: A fastening tool for driving a fastener into a workpiece is described herein. The fastening tool includes a contact trip, a magnet, and a magnetometer. The contact trip is disposed at a first end of the fastening tool and is configured to move toward a second end of the fastening tool opposite of the first end when the contact trip engages the workpiece. The magnet is configured to generate a magnetic field. The magnet is coupled to the contact trip such that movement of the contact trip causes the magnet to move. The magnetometer is configured to detect a change in the magnetic field generated by the magnet when the magnet moves relative to the magnetometer and, based on the detected change in the magnetic field, to generate a signal indicating when the contact trip engages the workpiece.