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liudr
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I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 7:11 am

D+ and D- of the USB port. That turns it from a computer geek's toy into a key component of a more custom electronic device. Designing 2-layer PCB is cheap and not too hard to learn. With a 2-pin header for D+ and D-, you can design a simple expansion board and bring out the USB, throw on a 4-port hub design you find form the internet (:D), a few buttons and LEDs, add some motor drives etc and you're getting your custom system, maybe a nice robot, whose guts don't look like a spaghetti monster . I don't know where to make suggestions/pleas for design changes and doubt anyone will take it from me, but since this is off topic, why not?
Arduino data loggers, user interface, printed circuit board designer since 2009, RPI 3B 2B 2B Zero Jessie, assembly/C/C++/java/python programmer since the 80's

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rpdom
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 7:25 am

Possibly those could be added as holes to connect a header to, which is a good suggestion, but fitting a header as standard to the Zero is not possible for the same reason that none of the other headers are populated - cost.

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bensimmo
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 9:25 am

Not just the zero either but you would need to make it a standard place across all new PIs for HAT style compatibility.
With the zero could you not make a reverse hat for the rear side and touch the pads on the back?

At least I assume that's what PP22/23 could be used for?

Not universal though.

gregeric
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 10:17 am

bensimmo wrote:Not just the zero either but you would need to make it a standard place across all new PIs for HAT style compatibility.
With the zero could you not make a reverse hat for the rear side and touch the pads on the back?

At least I assume that's what PP22/23 could be used for?

Not universal though.
Yes, connecting to D+D- on the underside has been exploited by way of pogo pins & wires soldered directly. No other Pi model (except the A+) is in need of USB expansion, so it can be a Zero-specific feature, not universal & outside of the 40-pin header.

Looking at the Zero 1.3 X-ray image, there appears to be space for extra through holes for such an enhancement - doesn't look too busy with tracks to the right of the TV/RUN header. Might just be able to squeeze in an extra 2 or 4 holes and push that second fiducial further over to the right (for those interested the other fiducial is hidden from view under the HDMI connector).

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bensimmo
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 11:02 am

I would keep it A+ compatible, looking at the B+/B2/B3 run has moved around and isn't in the same alignment as the Zero but putting a USB pin solder hole in a universal position opens the A+ up to tidier HATs (being an A+ user here)

Also the operation it to piggyback an a Zero as a OtG connection on an A+ just for the sake of a can do.

Also would it not open HAT developers if it became a universal position to using USB 'protocols' and hence an alternative serial connection other than the UART and the problems the reconfiguration the Pi3 has caused with various people and their setups, to shoehorn Bluetooth on?
I.e a place to connect easily without having it sticking out the side.

(I don't know the differences between all the many communication protocols on offer already other than UART for thngs like gps etc)

W. H. Heydt
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 3:12 pm

This is the sort of thing (relatively simple 2 layer PCB expansion) the Compute Module is designed to do. Asking for it on the Pi Zero is barking up the wrong tree.

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liudr
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 4:22 pm

The test points PP22 and PP23 have been moved between version 1.3 and earlier version(s), so I read. I was unable to get one since I live on the "wrong" side of the ocean. Only recently did I find time to drive 1.5 hours one way to get one rpi-0 for myself (V 1.3).

Here is some reading about change of test point locations:

https://www.kickstarter.com/projects/17 ... ts/1585369

[Warning for venting]
For the fellow saying I should have used pi compute module, you are either an expert electrical engineer, or you have no experience designing or soldering a printed circuit board. Maybe you missed the fact the compute connector has over 200 tiny contacts on a plastic housing. My in-house reflow oven (aka toaster oven on a variac) will be unable to reflow this part. That's shutting maybe 99% diy hobbyists while adding 2 pin holes to rpi-0 will bring maybe half of them back to the game.

I know that RPF wants their pis to teach kids how to program at a price point kids can afford. But seriously how many of us on the forum are kids just barely affording $35 toys? The foundation, in my opinion, has NOT even become close to its goals. That 8 million sales figure is just a way of saying that yeah, computer geeks like ourselves like this little toy just too much. Some of us went back for more boards and teach our kids pis, cause we didn't have this when we were kids.

So if you take that spirit of letting the users decide what to do with your products, I guess the $5 module is just their way of testing the water to see what users can do with just $5 module. Of course you can do your old trick, USB hub, spaghetti cable monster etc. and have a little fun with just another cheap computer. I have 3 laptops, 3 tablets, and a nice smart phone, plus all my pis. How many more computer do I have to have?! But what if some want to use it as a module in a custom system, like a data logger, or interactive toy or some assist system for seniors? Will spaghetti monster work? Maybe that will drive up the sales and new projects and directions people will find after getting this board? Keeping with the goal of making computers, or letting users decide some of the future direction? Arduino LLC is an example where the designers rarely want anything from the community. One thing they did that rpf didn't do is they have maintained their goal to make affordable electronics for artists and hobbyists easy to use. They struck their goal early on. They tried to make computer-like boards also but eventually didn't do it.
Arduino data loggers, user interface, printed circuit board designer since 2009, RPI 3B 2B 2B Zero Jessie, assembly/C/C++/java/python programmer since the 80's

fruitoftheloom
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 5:28 pm

Anything is feasible, Eben Upton has stated the RPi Zero Form Factor is not set in stone, so maybe a change will happen, when, that is a questioned which RPT will never answer.
Rather than negativity think outside the box !
RPi 4B 4GB (SSD Boot)..
Asus ChromeBox 3 Celeron is my other computer...

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bensimmo
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 5:37 pm

Saying use the compute module is saying the same thing to any user using any expansion or HATs.

This is a simple addition for two hole for the USB, hell they have TV holes which are used less frequently than or use hubs, surely they could have used the compute module for TV out instead?

Anyway,
I thought the compute module was for industrial purposes where they are needing something with a lot more flexibility than the basic of the standard Pi?

Pp22 & Pp23 seem to be in the same place on my 1.2 and 1.3 pp1&6 have moved and some other.
If people are soldering to them as people seem to be and building HAT for them then users must be using them? Seems an ideal situation to standardise their use as you cannit rely on test points.
They managed adding a camera connector which I'm sure a lot don't use either. Must cost more to add that then some extra holes? Who knows where the zero will go.

It not exactly and extreme and complete change of things idea.

gregeric
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Re: I really wish RPI-0 had these two pins!

Sun Jul 10, 2016 6:25 pm

W. H. Heydt wrote:This is the sort of thing (relatively simple 2 layer PCB expansion) the Compute Module is designed to do. Asking for it on the Pi Zero is barking up the wrong tree.
Creating a CM carrier board (in 2 layers!?) is at the other end of the difficulty scale from crafting home brew Zero expansion boards. The Zero at $5 very much fits the bill as the beginner hardware hacker's Pi - cheap enough not to worry about breaking it.

blc
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Re: I really wish RPI-0 had these two pins!

Wed Jul 20, 2016 1:07 pm

W. H. Heydt wrote:This is the sort of thing (relatively simple 2 layer PCB expansion) the Compute Module is designed to do. Asking for it on the Pi Zero is barking up the wrong tree.
... No.

I'm a relative beginner when it comes to PCB design and I'm taking on a Compute Module project. Just designing the voltage regulation will tie me up for a while, even if I copy the designs from the official open source breakout board (and even then they may not be sufficient for the power that the CM3 might need).

Soldering 4 wires to to D+, D-, 5v, and GND is far far simpler than designing a custom PCB which needs a 200-pin 0.6mm pin pitch connector and at least 3 different power circuits.

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