Introduction
The LattePanda Alpha is a board that I have talked about in my Black Friday Guide. Specifically, I got an Aluminum Alloy Passive Cooling Case that doubles up as a heat sink, as well as a Streaming Cable which would allow me to plug my board into any other computer and have that computer function as an interface for my board.
Unlike Single Board Computers (SBCs) like the Raspberry Pi, or Odroid (the 2 other SBCs I have used substantially), the LattePanda refuses to compromise on performance.
With benches coming in above the Macbook and a Lenovo notebook equipped with a 5th Generation Intel i5 processor, it is no surprise that the board comes in at a cool USD269 for the base configuration (no soldered memory, no OS). In contrast, the latest Raspberry Pi at the time, the 3B+, could be gotten on sale at USD35, while Hardkernel’s most expensive board, the Odroid-H2 costs USD111.
While some Makers have a habit of enclosing all their boards in cases, I am not one of them. Unless the project calls for protection from the elements, I am generally happy leaving boards outside, where they get to enjoy the benefits of ambient breezes, since most of the boards I use are tough enough to withstand a little abuse.
However, the LattePanda Alpha is not just any other board. Having paid SGD400+ for this board (I got the variant with the eMMC and installed a 500GB Samsung SSD), I was not prepared to leave anything to chance.
Case Considerations
At the time of purchase, I envisioned the LattePanda Alpha to be powering some of the more computationally expensive robotics projects that I was working on, such as this Robocup Junior Soccer demo robot. However, my busy schedule meant that these projects were going to be shelved for a little while. In the meantime, I decided that I should not let the board go to waste. Rather than have it sit in a box, I’m using it as my desktop replacement to get a feel of its real world performance compared to the Single Board Computers I have worked with in the past.
With this frame, I came up with a list of features that the case should have.
- Case should acknowledge the fact that there are GPIO Pins
- Jumpers which may be used to connect to the GPIO Pins should sit comfortably within the case
- GPIO Pins should be accessible (enough)
- When required, I should be able to remove a part of the case to fully expose the GPIO Pins
- Permanent Peripherals should have their cables hidden away
- USB ports for more temporary peripherals should be exposed and inviting
- Case should make it difficult for anyone to touch the back side of the PCB and short both the board and my bank account out in the process
- Case should be airy enough such that the built in fan can work as intended, with no part of the board sealed in as it would exacerbate any heat dissipation issues
- Case should incorporate breadboards to make prototyping easier
- Footprint shouldn’t be massive as it’ll be a permanent fixture on my already cluttered desk
- Case should look as good as possible (although this is subjective)
- Case shouldn’t be too hard to build with easily available tools and materials
Implementation
The first step in the design process was to figure out the dimensions of the board. Thankfully, the LattePanda team supplied a CAD model from which dimensions could be extracted.
Placing the board on its side was a straightforward decision as it would reduce the footprint of the case and elevate ports above the clutter of the desk underneath. While it was desirable to me to keep the width of the case as small as possible, doing so would make it less stable laterally as it is already pretty tall. To counter this effect, the base was pegged at the width of a quarter-sized breadboard (plus a little tolerance). Placing the (relatively) heavy breadboards there also served to shift the Center of Gravity (CoG) closer to the ground, increasing stability, and allowed for all prototyping and cabling to be confined to the case. Any accessibility issues that arose were solved with design features discussed below.
To accommodate the GPIO pins, the main part of the case was split into 2. The main case would cover up the back of the board while leaving the front, where the GPIO pins were, exposed. This also allowed the bulk of the case to be relatively thin, with a removable, protruding section over the board whose distance from the main case could be adjusted depending on the dimensions of the jumpers and the stiffness of the wires. An additional cutout was made for the bottom row of GPIO pins to improve accessibility.
Since the board was going to be used as my Desktop, cables such as the USB C used for power delivery, as well as the HDMI (going to my monitor) and the 3.5mm Audio Jack (going to my speaker setup), were going to be a permanent installation. As such, I angled them down, providing sufficient material to cover up most of these cables to prevent them from being unsightly. Their natural stiffness also meant that they clustered together when hitting the table, making them easy to manage while preventing the case from tipping back when peripherals were inserted at the front. If these cables were not angled, the cables would have been suspended in the air, weighing the back of the case down and compromising its stability.
Angling the board also tilted the USB ports up front upwards, creating a much more inviting feel. Plugging peripherals in was also more reassuring this way as the force exerted to do so is distributed both down (towards the table) and back, instead of having the ports face purely forwards, which would result in the case being pushed back every time a USB device was connected.
As can be seen from its front profile, the case allows air to flow freely front and back, up and down. The supporting structures on the sides have large cutouts, only solidly filled to cover up cables (at the sides at the back of the case, as well as a small front panel under the USB ports), or the bare board. The removable side panel also features slits to promote airflow brought about by the built-in fan
Thankfully, I have access to a Laser Cutter through my university, which meant that I could cut and engrave acrylic with ease. Without the Laser Cutter, I would have had to cut the outlines with a jigsaw and forgo the ventilation slits on the side panel as they would have been a huge pain to create. I chose to use Matte Black Acrylic for the bulk of the case to create a contrast with the brown wood of my table top, with the Side and Front Panel done with Mirror Acrylic to provide a faux metallic look. Where needed, the case was held together with Black Nylon M3 Standoffs to complement this look. Some additional engraving was also added for aesthetic purposes, with my name added to one too many places to feed my ego.
The final product was slightly different from the initial CAD included in the screenshot above. While I had access to an Acrylic Bender, I found it difficult to use as the folding would have to be extremely precise for the LattePanda mounting holes to line up front and back. As such, the more aesthetically pleasing screw-less case gained a couple screws to make building less of a pain. Ultimately, this change meant little as the base of the case is largely obscured by the clutter on my tabletop.
[Download the Original CAD here]
Conclusion
After months of use, I have been satisfied with this case! Unfortunately, too many cases available in the market do not balance aesthetics and functionality well. Even with the limited resources available to Makers, it is possible to create a well-designed product without too much time spent (I might have spent more time writing this article than actually making the case). At the end of the day, technology should only be the enabler, with User eXperience taking center stage. This would require the Maker not only to develop his technical abilities (CAD, tooling etc.), but more importantly, the sense of empathy towards the end user.
What’s Next
While the case has served me well over the past months, I have noticed that the board tends to heat up with more demanding applications such as photo processing. This is understandable as my regular laptop (an Alienware with an i7-6500U and a 965M) slows down on some of these tasks as well. I was not too bothered as a result, but DFRobot’s Black Friday Sale provided a good opportunity to acquire a cooling solution at a lower price.
My next project for the LattePanda would be to house it in my newly gotten enclosure, install a 40mm fan, and to design a case around this new set-up. Till then~