Amazon.com: Icstation DIY Light Sensor Sound Module, Micro USB Recordable Sound Chip 8M Memory Speaker Talking Programmable Music Player Box for Birthday Greeting Card Father's Day Creative Gift : Electronics
How to Make FLEX Sensor at Home | DIY Flex Sensor : 9 Steps (with Pictures) - Instructables
How To Build A Smart Home Sensor | Popular Science
Building a DIY digital camera sensor is as tricky and tedious as it sounds
DIY temperature sensor
DIY Filament Runout Sensor for 3D Printer Fault Detection using Arduino
My $8 DIY MQTT-enabled occupancy sensor. (Details in comments) : r/homeassistant
Finger Bend is a DIY textile flex sensor | Arduino Blog
Make an IR sensor module for Arduino | Proximity sensor by yourself - YouTube
I Made My Own Image Sensor! (And Digital Camera) - YouTube