Review on DAOKI KY 003 Effect Magnetic Arduino by Ernest Etienne

All 10 modules I received worked as expected - LED lights up when the magnet is raised sensor. My only problem was the lack of documentation; However, I contacted the seller (DAOKI) and he promptly replied via email with a link to arduinomodules.info/ky-003-hall-Magnetic-sensor-module. Thanks to the seller for the responsiveness! The sensitivity isn't as high as I hoped for my application, but it's enough. My cursory testing of various magnets shows that lower quality magnets cannot be reliably detected, but neodymium magnets have a strong enough field to be reliably detected. Alignment of the sensor and magnet significantly affects the sensing range, but will constantly switch when the neomagnet is within 0.5-0.75 of the sensor's spherical range. The size/field strength of the magnet is the main factor that determines the range. This is probably not the best choice if you need high accuracy in your application, but good enough for limit switches, speed detection, etc.