IOT Compass

A project I’ve been working on for the last couple of weeks is the IOT Compass. It’s mostly software and electronics so I’ve been writing my build up on the Element14 community and posting the code on Github

The idea is similar the Captain Jack’s compass from the Pirates of the Caribbean. You tell the compass where you want to go and it points to it. The project uses the Azure Sphere and will be connecting to Azure Functions and Azure IOT Hub. I’m moving the pointer with a small stepper motor. As with the Topsy Turvy Clock it will need a mechanism to identify the position of the pointer when it first starts up. I’m using a reflective opto sensor and have successfully connected up both the sensor and the motor. 

For this to work, the sensor needs to be positioned next to the stepper motor so I designed a small housing to be 3D printed.


I used Fusion360 to design the part. I decided to use the construction lines feature as that would make referencing the part locations straightforward. All the types planes are the same so the options are really about how you create them in reference to the other parts.

First I created a block for the base then I added a couple of mid-planes to show me where the centre was. That would be the position of the motor axis. The mountings for the motor were 10mm from the spindle so I added an offset plane for that and used it to make a hole for the main body of the motor. Then added two more offset planes for the mounting holes. That does make for a lot of planes but you can show and hide them as needed.

Sketched shapes to be pushed into the plate

I used these to create some mounting holes then sketched on some rectangles a little larger than the mounting lugs. The corners of the rectangles were filleted to match the outline of the lugs. The sketches were then pushed in 1mm.

More offset planes were added for the mounting blocks in the corners and these sketched and pulled. A cutout for the motor cables was sketched and pushed all the way through. Finally, a tray for the opto-sensor was added by sketching and pulling up and pushing down.

Construction lines were something we were taught when learning drafting at Dowty and the idea translates well to CAD. Using construction planes definitely helped me create this drawing faster than I would have otherwise done.

2 thoughts on “IOT Compass

  1. […] nothing particularly sophisticated about this design. I created it with similar techniques to the base plate using construction lines to find the middle and 2 more 1.6mm from the centre. A 5.2mm circle was […]

  2. […] took the work I had done on the Azure Sphere based IOT Compass and ported it over to the Arduino MKR1000. There was a couple of reasons for swapping platform. […]

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