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  • Author Author: stmorgan
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Metal Enclosure for RIoTboard

stmorgan

This post describes a metal enclosure suitable for use with the RIoTboard provided you have some time and access to the proper tools.

 

I have been looking for an enclosure for my RIoTboard for a number of reasons:

 

1.  I have a tendency to inadvertently press the reset switch (S1) if I use the board in my workspace without any enclosure and attempt to move the board.

2.  My workspace is prone to static discharge for a number of reasons, and I would like to avoid frying the board.

3.  I have radio equipment in operation in close proximity, and I need a means to prevent RFI from the RIoTboard and any associated equipment.

4.  I would like to mount additional hardware such as a Real Time Clock (RTC), etc. for use with the RIoTboard.

 

All these factors pretty much dictate using a metal enclosure for the RIoTboard.  After some research, I settled on a CU-3005A enclosure from BUD Industries.  This enclosure is aluminum and measures 5 inches x 4 inches x 3 inches (12.7 cm x 10.16 cm x 7.62 cm).  More information is available here:

 

http://www.budind.com/view/Small+Metal+Electronics+Enclosures/Miniboxes

 

This enclosure has no pre-drilled holes or openings, so it is necessary to drill mounting holes and create openings for access to any desired ports.  I have access to a drill press and a variety of drill bits and metal files, and these were sufficient for the task.

 

Here are some photos of the RIoTboard and enclosure:

 

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As can be seen from the photos, the enclosure is barely large enough to accommodate a RIoTboard with an SD card inserted in the J6 slot, if the board is mounted with the audio connectors (on the other side of the board) flush against the inside of the enclosure.  I have created openings only for ports I plan to use externally, but it would be a simple matter to add additional openings if needed.  I used #4 screws, lock washers and nuts to mount the RIoTboard in the bottom of the enclosure.  I also added a small opening on the end with the Ethernet and USB ports to accommodate a Serial Debug Port cable on the J18 connector (visible in the lower left of the fourth photo).

 

Nothing fancy, but it fit the bill with a total cost of less than $10.00US for the enclosure and mounting hardware.  Now I need to put my Embest LCD8000-70T in a metal enclosure as well...

 

7 January 2018 Addendum

 

It turns out that this enclosure nicely accommodates some of the available add-on boards that connect through the RIoTboard GPIO pins provided the RIoTboard is mounted as indicated above.  For example, the RIoTboard Adapter can be inserted with plenty of room for attachment of the various types of hats and expansion boards that it supports:

 

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The LCD-EX module that is used to connect the Embest LCD8000-70T 7-inch display also fits within the enclosure:

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I have cut a slot through which the ribbon cable from the LCD8000-70T can be connected to the J1 connector on the LCD-EX.

  • in reply to dougw

    Thanks.  I find it even tougher to get through one without personal injury.  I got away from this one with just a small thumb perforation.

  • Nice work - it is tough to get good precision in this type of build.

  • in reply to balearicdynamics

    I guess it depends on exactly which set of frequencies you want to block.  I was looking at the Wiki article below, and I wasn't really aware that, if you are going to use an aluminum shield, you need approximately 100 times the thickness of a steel alloy to get the same level of shielding for a particular frequency (see the Skin Depth vs. Frequency graph):

     

    https://en.wikipedia.org/wiki/Faraday_cage

     

    Generally speaking, for the frequency ranges I want to block, just about any kind of metal would suffice, and aluminum has the advantage of being reasonably inexpensive and soft enough for me to fashion with a drill press and hand tools (metal files).

     

    As I mentioned in the original post,  I really need to get a shield for the Embest LCD display.  I have noticed the same issue with an HDMIPi LCD display that I just purchased as well.  The vertical and horizontal refresh signals (say 50-150 Hz) on these devices generate harmonics extending above a GHz, and you are just shooting yourself in the foot if you fail to use an adequate shield but still expect to do any kind of radio reception in close proximity to these types of devices.

  • in reply to DAB

    Yeah, I've been an amateur radio operator for over 35 years now, so I have learned through decades of sometimes exasperating personal experience about the need for proper grounding.  In fact, I am fortunate enough to have a copper ground rod just outside the window of my workspace with a short length of large diameter aluminum ground wire to bring the ground connection into the building.

  • As you have a radio device nearby I assume you are more expert than mine. Does the Aluminium enclosure is sufficient for radio insulation instead of iron?

     

    Enrico