I purchased allegro a1324 sensors from Mouser, and my magnets are removed from tiny motors used in micro helicopter toys. They are about 5mm diameter and 15mm long, and are polarized diametrically. The hall sensor is placed at one end of the magnet with it's top facing it. I am just trying to figure out a way to get the extra ~1000 steps to get closer to full range of the MCP3208. I want to thank you again for your work. I am a stay-at-home dad and have plenty of time to tinker with projects like this.