Toner level sensing using rotatable magnets having varying angular offset

An electrophotographic image forming device, comprising:

• a reservoir for storing toner;
• a rotatable shaft positioned within the reservoir and having an axis of rotation;
• a first magnet and a second magnet connected to the shaft and rotatable around the axis of rotation in response to rotation of the shaft, the first magnet is fixed to rotate with the rotatable shaft, the second magnet is rotatable independent of the rotatable shaft between a forward rotational stop and a rearward rotational stop such that an angular offset between the first magnet and the second magnet varies depending on a rotational position of the second magnet relative to the forward rotational stop and the rearward rotational stop;
• a sensor positioned to sense the first magnet and the second magnet at a point in their rotational paths;
• and
• processing circuitry in electrical communication with the sensor and configured to determine an amount of angular offset between the first magnet and the second magnet and to determine an estimate of an amount of toner remaining in the reservoir correlating with the determined amount of angular offset between the first magnet and the second magnet for each possible rotational position of the second magnet between the forward rotational stop and the rearward rotational stop.