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Perfecting Pocket P.C.

After a period of intense effort, we are back with an update with the latest developments with Pocket P.C. From onboarding a new factory to sourcing components, manufacturing a D.V.T. followed by board bring-up and formal verification all took much longer than originally anticipated. Now that those are all completed, we have a lot to share with you.

Our first production run with our new factory went extremely well. We manufactured 25pcs for a D.V.T. or Design Verification Test. We are extremely impressed with their production facility, processes, competence and skill that they demonstrated in getting the PCBs assembled. We were pleasantly surprised how thoroughly the factory performed during every step of the process.

After assembly, we did a formal verification which took a few weeks. We carefully examined every aspect of the project down to every single component.

As a result of exhaustive testing, we determined that we will have to do a second D.V.T. This will add a few weeks to our shipping timeline but we feel it is worth it to resolve a few critical issues that we encountered. We want to resolve these issues and test that the solutions are sufficient before starting a P.V.T.

  1. We accidentally swapped a few data lines in the PCB. This meant the RAM, SD, and one of the USBs did not operate as expected.
  2. A newly added power protection component interferes with the enclosure preventing it from closing properly.
  3. The LoRa antenna selected was not optimal for the location on the PCB. We had a meeting with the antenna manufacturer and they recommended a bigger antenna with a different layout requirement. The advantage of this antenna is that it is the same part for both low and high frequency bands. This antenna should also allow for better range than the previously selected component.

Following our formal verification, this week we had a productive meeting with representatives from all the factories involved in the manufacturing Pocket P.C.’s components. We wanted to ensure that everyone is on the same page. Each factory made their recommendations on how to improve the product and manufacturing process.

Mechanical

As you can see above, the keyboard is almost there.

Here are a few things we noticed and will be correcting in the next version:

  • The status LED is a little too bright which causes the blue to bleed into the main keyboard when it’s on. This is solved easily by increasing the resistance of the LED resistor to make the LED not as bright.
  • A backlight cover film is missing over the LED where the newly added “+ and -” buttons are which is why the keyboard is slightly brighter there. We will correct this in the M.P. keyboard cover film.
  • The keyboard was silkscreen by hand which means it is not as sharp as the M.P. version and the black is too thin. We will ask them to do two passes of black in the M.P.
  • There was a software file glitch at the factory which caused the rightmost button on the bottom to show question marks instead of the actual characters. We will ask them to correct and carefully review the silkscreen stencil against the proof before doing the silkscreen in the future.
  • Some characters are hard to read so we will be making them bigger in the final version.

Something which we believe we haven’t mentioned and would like to make you aware of is that the back cover screws into the front cover with 10 screws. This means that Pocket P.C. can be easily taken apart without great risk of damaging it during disassembly.

The assembly factory made a suggestion that we use hexagonal or triangle screws but we informed them we did not want to make it difficult for users to open by requiring a special screwdriver. We will most likely end up using phillips screws if there are no assembly issues during mass production that would require otherwise.

Electrical

Besides the main issue of swapping data lines, we carefully reviewed the schematic and layout in its entirety and made a list of changes for D.V.T. 2.

If you are interested in what changes we will be making in the next revision, you can follow along with our changelog here:

Pocket P.C. Rev 2.1 Changelog

Further, we are commissioning an outside engineering firm to double-check everything. They will review the schematic and layout to make sure we don’t miss anything and they will give us an outside opinion on the overall design.

Software

We decided to scrap our initial Arduino-based firmware for the Keyboard/System controller in favor of QMK (Quantum Mechanical Keyboard) Firmware. You learn more about this firmware here: https://qmk.fm/

According to their website, “[t]he goal of the QMK software project is to develop a completely customizable, powerful, and enjoyable firmware experience for any project – keyboard or otherwise – and to provide helpful, encouraging, and kind support and feedback for people with any software development experience.”

Most of QMK itself is under GPL v2, but it includes software that are under various other licenses. We intend on upstreaming our changes to the original repository when they are ready.

As for the main software running on Pocket P.C., we will be working with Bootlin, an embedded development firm, to upstream everything from U-boot specific changes including Device Tree, Linux Kernel changes including Device Tree, Buildroot configuration and an Armbian build configuration.

This means that not only will we be supporting Armbian in addition to Debian but this should make it much easier for other distributions to be supported once the changes are accepted upstream.

Final Thoughts

If anyone has emailed us in the past few weeks, we will respond to all your questions soon. We apologize for falling behind in responding to customer inquiries but please know that we have been extremely focused on doing what needs to be done to get an excellent product shipped to you soon as possible.

We’ve taken a lot of pictures and videos which we have to edit together and are planning on sharing those soon.

Thanks for being a part of this great project.

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