Hello again and thanks for being a part of the Pocket P.C. community. We are excited to give you another update as we head into the final phase — the manufacture of the product you have been waiting for.

We had a production run in early February and a successful board bring-up for DVT2. We only had five PCBs assembled for this production run because had not worked with this factory before. We normally produce 25 units for a DVT.

Below are some photos from the assembly process:

Automatic Optical Inspection (AOI) of the PCBA after assembly.

Here you can see the LoRa antenna lettering being inspected. This is to ensure that the correct component has been placed. This is one of hundreds of points of analysis that the AOI machine does for each PCBA.

X-ray Inspection of the PCBA after AOI.

Here you can see again the LoRa antenna. The antenna is actually made of a special PCB and here you can see the traces on the various layers.

The factory owner personally helped us to test each device after all PCBAs went through AOI and X-ray analysis. After all boards were tested and powered on successfully, we carefully wrapped each board and headed home. When we finally left at around 10PM all the workers left for the holiday. We made it just in time!

The next day we shipped two units to Bootlin. They quickly got to work once they received the package. And the results are in!

First boot demonstrated in short-run of DVT2 PCBAs.

Taking Pocket P.C. out of the lab and into the wild.

YouTube

We have started to post progress videos on YouTube which are being posted regularly. Make sure to subscribe to our channel to view our latest Pocket P.C. videos as they are released.

A video of flashing the keyboard / system controller with the built-in Black Magic Probe and a demonstration of a working keyboard will be uploaded next week.

Software Development

We will be working in the public and pushing changes to the following repositories for our U-boot, Linux and Buildroot changes respectively. Once the changes are thoroughly tested, we will be submitting patches upstream so that you don’t have to use our repositories.

https://github.com/PopcornComputer/PocketPC-Uboot
https://github.com/PopcornComputer/PocketPC-Linux
https://github.com/PopcornComputer/PocketPC-Buildroot

Circuit Design

There is a lot of protection circuitry in Pocket P.C. — much more than most standard consumer electronics including most cellphones. We want Pocket P.C. to be a high quality and durable tool in your toolbox (or your pocket!)

As a result of studying this latest production run, we added five protection diodes in various parts of the PCB to prevent damage that can occur when using faulty chargers or cables. We also added a voltage regulator to the USB Serial port that can accept up to 30V. We always keep in mind that some defective USB-C chargers can output 20V by default without power negotiation which could cause some parts including the USB Serial converter to fail short, permanently ruining it. By adding the voltage regulator, the USB Serial port can handle these types of situations. We are doing everything possible to prevent cases of unintentional damage to Pocket P.C. to ensure that you will be able to continue using it for a long time.

During software development for the LoRa module and keyboard / system controller, we realized it would make things easier if we could use a UART to debug the firmware. The great thing about the built-in dedicated Black Magic Probe (BMP) device is that it offers us an additional UART. We have added an analog switch to share the UART on the BMP between the keyboard / system controller and the debug UART on the LoRa module. The LoRa module will now have both its UART1 and UART2 connected to a functional UART. It must be noted that the UART on the keyboard / system controller is shared with a ROW and COLUMN of the keyboard. If you are using the UART it will interfere with the operation of the keyboard. Just something to keep in mind.

We contracted a few engineers to do a full review of the design and outside of a few minor suggestions we gained their approval of the overall design. This gives us additional confidence that Pocket P.C. will be a reliable tool.

Next Steps

We will be doing another quick (10-15 day) production run to verify some of the changes we introduced into the latest version as a result of the lessons learned in the last production run.

After that, we will move straight into Production Validation Test (PVT) with Mass Production (M.P.) right after. The PVT should be less than 2 weeks to verify that our process to produce Pocket P.C. is sufficient to do so with high precision and without introducing defects.

Final Thoughts

Overall, at this point we are pleased with the design. This gives us confidence that Pocket P.C. will be a reliable tool you can depend on. We have about a month of development and additional testing before we can start PVT. This puts us into Q2 of 2021 as an anticipated ship date.

We will have a limited number of units available for evaluation for business use. If you have an urgent need to evaluate Pocket P.C. for your business, please reply to this email and we will try to accommodate you.

We appreciate your continued support and encouragement.

We promise to give you another detailed update as our exciting project continues toward completion.