Arduino Nano + 2x Hall sensors

thingiverse

This is a custom mount designed specifically for an Arduino nano v3 and two ACS7XXX hall sensor boards, similar to these: https://www.amazon.com/gp/product/B01FA2P1YW/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 The model was printed at 0.3mm resolution with ABS filament, but other filaments should also work well. The maximum overhang angle is 45 degrees, which all printers can handle without requiring supports. All three slots are designed to allow you to slide the boards in from the top side. The nano slot features claws on its four corners that snap around the pin headers to securely hold it in place. The hall sensor slots are tapered with end stops located at their bottom side. Two screw holes are sized for 4mm wood screws or similar fasteners (drywall screws were used in this case). It is possible to fit up to four hall sensors on this mount if needed. If you do this, you may want to use a razor to shave off the small end stops from the hall sensor slots first. With four hall sensors installed, the wire screw housings will hang over the edge of the mount, but the friction fit will typically hold them in place (except possibly in automotive or other extreme vibration environments). As shown in the photos, the hall sensor slots can also be used for custom PCBs. In this case, a nano is being used to add analog inputs to an RPi (for Hassio serial sensors). The hall sensor measures 12VAC doorbell current, while two voltage dividers on the DIY PCB measure backup battery voltage and the state of mains power. Note that the divider does not connect directly to mains voltage; it only measures the output of a 14VDC brick serving as the primary supply for my Pi.