After reading some the Shapeoko community’s experience with mechanical end-stops, I decided to design my own hall-effect based sensor solution. I’m not saying I went about it the right way and there are probably better/cheaper/faster solutions, but it’s what I came up with. I should say, I was inspired by Kevin Patterson’s hall effect solution (love the red/green feedback LEDs.) https://www.youtube.com/watch?v=vqU_5wZAX3s6
NOTE: This design has not been implemented yet. Still waiting for one more board from OshPark to arrive.
* 24V separate power supply for the hall effect circuit.
* Nominally high (active low) design.
* Opto-isolated sensors
* Higher sensor voltage (24V) in combination with some simple pull-ups an caps to help ride out any coupled transients.
I’ve built some acrylic holders for the sensor boards and a small enclosure for the main board. The concept is similar to Kevin’s in that I will have 6 sensors (2 for each axis) connected with inexpensive phone cord connected by RJ11’s to the main board. I’ll mount my main board to the side of my control box where the grblshield/arduino lives.
The PCBs are available to purchase or download the gerber files (PCB build files needed by a board house to make printed circuit boards) from Oshpark.com.
Main Board: https://oshpark.com/shared_projects/RHwVNxOU1
Sensor Board: https://oshpark.com/shared_projects/B7TXAfxt2
BOM: (Note: I recommend the DRV5023AJQDBZR for the Hall Sensor instead of what’s on the BOM. The one in the BOM is a latching version and shouldn’t be used. Use Digikey PN: 296-38452-1-ND)
As I build and test this concept I’ll try to post my results. Hope this helps some of you.