Manual override for auto-dimming rear view mirror

thingiverse

UPDATE: After several weeks of using this product, I'm thrilled with its performance. Manual control over the dimming of all 3 mirrors is now easily accessible when the automatic feature fails, which happens frequently enough. Every car would greatly benefit from having one of these installed. I recently purchased a new vehicle equipped with an advanced rear view mirror dimmer system. When functioning properly, it effectively dims all 3 mirrors, meeting my expectations. This automatic dimming technology relies on two key sensors: an ambient light sensor positioned forward through the windshield and another sensor positioned behind the mirror, detecting headlights from trailing vehicles. As night falls, the ambient light sensor triggers the second sensor to adjust the mirror's brightness if necessary. However, living at a latitude of 60N introduces unique challenges. Our extended dawn and dusk periods often confuse the ambient light sensor into thinking it's daytime, resulting in inadequate dimming when I'm still subjected to glare from following vehicles. Unfortunately, there is no built-in manual override option available, exacerbating this issue. To resolve this problem, I employed a clever workaround: tricking the ambient light sensor into believing it's nighttime, as demonstrated on https://www.thingiverse.com/thing:2889660 . Initially, I encountered printing difficulties, so I decided to design my own version from scratch, as shown here. This custom design can be printed flat on the bed. The primary component, known as the "frame," requires careful assembly using either super glue or thin double-sided adhesive tape. Before gluing, it's essential to insert the slider piece. When properly assembled, the slider will remain securely in place. To ensure optimal results, the parts must be printed with 0.2mm layers and a 0.2mm extrusion width, or less. If you reside in a hot climate, you may need to use ABS plastic; however, I've successfully used PLA without any issues.