Firearm safety mechanisms, visual safety indicators, and related techniques

A firearm comprising:

• a safety mechanism having a locked position that prevents discharging of the firearm and an unlocked position that allows discharging of the firearm, the safety mechanism comprising:
• a cam;
• a motor mechanically coupled to the cam, the motor configured to rotate the cam;
• and
• a trigger bar stop comprising a corner, the trigger bar stop having a first position in which the trigger bar stop prevents discharging of the firearm and a second position in which the trigger bar stop permits discharging of the firearm, wherein the corner fits within a recess of the cam when the trigger bar stop is in the first position and the corner is outside of the cam when the trigger bar stop is in the second position;
• a fingerprint sensor located on an outer surface of the firearm, the fingerprint sensor configured to generate a fingerprint scan of a finger contacting the fingerprint sensor;
• a light source located proximate the fingerprint sensor, wherein the light source is configured to emit light along an outer boundary surrounding the fingerprint sensor;
• and
• an electrical circuit configured to cause the safety mechanism to move between the locked position and the unlocked position at least in part by causing the cam to move the trigger bar stop between the first position and the second position.

A firearm comprising:

• a safety mechanism having a locked position that prevents discharging of the firearm and an unlocked position that allows discharging of the firearm, the safety mechanism comprising:
• a cam;
• a motor mechanically coupled to the cam, the motor configured to rotate the cam;
• and
• a trigger bar stop comprising a corner, the trigger bar stop having a first position in which the trigger bar stop prevents discharging of the firearm and a second position in which the trigger bar stop permits discharging of the firearm, wherein the corner fits within a recess of the cam when the trigger bar stop is in the first position and the corner is outside of the cam when the trigger bar stop is in the second position;
• a fingerprint sensor located on an outer surface of the firearm, the fingerprint sensor configured to generate a fingerprint scan of a finger contacting the fingerprint sensor;
• a light source located proximate the fingerprint sensor;
• and
• an electrical circuit configured to cause the safety mechanism to move between the locked position and the unlocked position at least in part by causing the cam to move the trigger bar stop between the first position and the second position.