I'm looking forward to receiving my PocketPD soon! As a MicroPython developer, I was also interested in taking a stab at MicroPython firmware for the PocketPD, so I just thought I'd let you know that I've made a start:

https://github.com/mattytrentini/micropython_pocketpd

It's not quite there yet; I don't yet have hardware to test on which makes it challenging! But I do have a simulator (so I can test the interface in a browser) and there's also a web interface to the features of the device (over USB Networking - NCM - which itself is a feature still in development for MicroPython). 

Hi, we can't wait to mention it to the community once you are ready. Thank you so much for taking a swing with MicroPython.

感谢开源，根据公开的原理图和gerber，我成功复刻了这个作品，以下是我的复刻展示：

https://www.bilibili.com/video/BV1DoTEzrEfy?vd_source=62d02bd6a12185f94311a78dd4fcabe7

This looks awesome. Thank you for your video!

And I actually successfully added a barrel plug into the case, without removing any of the existing connectors:

https://github.com/CentyLab/PocketPD_HW/issues/4

Regards!

very refined and impressively finished

Hi, just came across your project on CrowdSupply.

I'll get one as they become available.

One question: you specify it up to 20V. The newer PPS spec goes up to 48V. Could you extend the design to go up to the max PPS voltage?

I think this would extend the usefulness and longevity of the project.

Hi Markus,

The PPS spec currently only go up to 20V max. I think that you are talking about AVS mode which allow voltage negotiation up to 48V at 100mV increment. However, the ICs for this is still very new and I think there might be 1-2 years before we can see more adoption of these voltage range.
We will have to perform more prototype and study for this max voltage, as higher voltage does mean more protection need to be implemented so the circuit doesn't die to due to user error.

Hi CentyLab, I just read up about AVS. Amazing how the USB Implementers Forum adds another new thing (AVS), instead of just extending PPS.

I can see that adding AVS is not trivial. Oh well, that gives you a goal to shoot for with a V2 of the device!

re: AVS vs PPS. I'm not a USB-IF member, but I think this decision makes sense.

The use case for PPS is directly charging small lithium ion batteries. That's the justification for supporting <5v output. That's also the justification for current limiting. By configuring current and voltage limits in the power source, a device like a cellphone or tablet can bypass it's internal charge controller, which means no heat generated on the device from that. No heat means the battery cell stays cooler and can accept high current for longer. Some devices have dropped from 1h20m charge time down to 1hr. It's substantial.

Above 20V you're looking at 5s and 6s battery packs. Laptops often have 3s2p (marketed as 6 cell battery), but even with 4.6v cells a 4s battery is <20v. Devices that use 6s and larger batteries tend to also use higher capacity cells (or parallel cell configurations). Fast current control is no longer as important, so charge current can reasonably be controlled on the device by periodically asking for a higher voltage whenever the current tapers a bit. But realistically, anything with 5Ah or larger capacity (like an eBike battery, which increasingly offer USB-C charge) are going to charge faster using an onboard buck or buck-boost circuit. Since these are larger batteries, the heat from a switching regulator has less impact (bigger mass) and also because they're bigger batteries, one can justify a larger inductor (more efficient regulation, so less heat anyway).

While extending PPS to 48v would be great for a project like this, I can't think of really any other device-side use cases that would benefit from it. The only reason USB-IF added it in the first place was for direct charge, and that has diminishing usefulness above 16v or so. Without the direct charge use case, I guarantee PPS would have stayed above 5v and would not have had current limiting. Without a good device-side usecase I think it's hard to justify adding cost on the supply side. From a software perspective, I agree it would be more elegant if PPS just went to 48v. But if they did that, probably the USB-PD sources would just refuse to implement it

Now, almost three months have passed after the last update.

What is the state of this? I really would like to buy one (kit with pre-assembled SMD parts, or complete).

Best reagards!

Hi Drei. We are now online on CrowdSupply, you can check the link on the top of the page. We have also received your email, and unfortunately we can't ship a beta sample to Germany due to some shipping regulation there. However, CrowdSupply should be able to handle that no problem.

Hi Drei,

Can you send us an email at CentyLab@gmail.com? We now have the capability to ship directly to Germany.

We would like to thank you for being here since the start.

Done.

You write in the descriptive text of this project

> Let us know if you want to be our beta user

I am interested; what do I need to do/ what do we arrange? (I am in Germany, European Union.)

Hi Dreil. We are currently out of the BetaUser unit but we are working with feedback to push out the new design. Due to some shipping waste regulations, EU shipment will be supported right after US shipment.

When this is ready, I am willing to buy a kit (at least PCB with soldered small SMD parts).

I opt for (an option to add) barrel jack socket as an output socket.

Hi Drei, do you have a picture of the type of barrel you are talking about?

I mean sockets for the widespread barrel plugs with 5.5 mm outer diameter/ 2.5 mm or 2.1 mm inner diameter, for [this kind of plugs](https://www.reichelt.de/hohlstecker-knickschutz-aussen-5-5-mm-innen-2-5-mm-hs-25-9-p8649.html).

Sockets are for example:

* https://www.reichelt.de/einbaukupplung-loetoesen-cliff-fcr681465-p227725.html

* https://www.reichelt.de/einbaubuchse-zentraleinbau-aussen-5-6-mm-innen-2-1-mm-hebl-21-p8524.html

* https://www.reichelt.de/einbaubuchse-zentraleinbau-aussen-5-6-mm-innen-2-5-mm-hebl-25-p8525.html

* https://www.reichelt.de/einbaubuchse-innen-2-1-mm-dc-bu21-90-p183502.html

* https://www.reichelt.de/einbaubuchse-loetanschluss-stift-2-1-mm-goobay-11135-p359356.html

Oh yeah, this can be done. I was just confused as the ports suggested are usually power input. I can add an overlapping footprint to one of the ports. Probably the XT-60 port. I am hesitant to increase the port number since it will break the form factor.

Drei, we have added an footprint for the 5.5x2.1 jack in the newer version. So you got to select between XT60 or 5.5x2.1 port.

Thanks!

I have long wanted to make something like this. I have also had an eye on MDP-P905 and DP100 for their compact form factor.
If you would make the next version of PocketPD in a similar form factor and with digipots instead of analog pots then I would really not hesitate to yell Shut up and take my money!
Until then I'd be happy to assist with anything.

Hi Martin, this current version doesn't use analog pot. It is already an encoder which technically is already digital.

I have an updated layout closer to the MDP-P905. Per area, this unit should be even smaller than the MDP-P905. Let me know what you think!

In that case I think exactly what I yelled before! :-)

I have a friend or two who will probably utter the same. Where can we sign up to buy? 

Hi Martin,

I will start the first small prototype batch in the US around the end of this month (April). Once confident with the prototype, we will open pre-orders on Lectronz for beta users. If the prototype unit works well, Elecrow will be our worldwide shipper.

We are working on an output filter for the circuit. We have been looking into LC and pi filters but have not yet been able to effectively filter noise at 22-24KHz from the USB-C brick. This noise starts to show up when pulling higher than 3A. It would be awesome if someone could help us with this filter design.

I love the idea of this project. are you going to release a BOM or more docs?

Hi Gringl, we are on the last stage of hardware prototyping. For releasing, the plan is to first release the software, and BOM. We will release the hardware file later to ensure the project doesnt get cheap cloned immediately.

Hi Gringl,

We have released the firmware that works on the BetaUser version: https://github.com/CentyLab/PocketPD