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xamal
Posts: 56
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Location: A Coruna, Spain
Contact: Website

New mini UPS hat for our Raspberry Pi

Mon Apr 24, 2017 9:01 am

Hi,

I would like to introduce you my first Kickstarter project for Raspberry Pi. It is a compact UPS for any 40-pin header RPi. The main features are:

- Energy for a few minutes (5-20 min depending on consumption) if power supply fails.
- RPi knows the estimated battery time to make a properly shut down.
- Compact solution. All electronic and battery are embedded in the own hat.
- Auto turn on when main power is restored.

Image

You can check this project here:
https://www.kickstarter.com/projects/xa ... spberry-pi

And here is a video with a demo:
https://www.youtube.com/watch?v=MjEoai59akM&t=17s

I hope you like it!!!
Any opinions, comments and suggestions will be welcome.

Best,
Francisco Dominguez
Xamal.es

Ongelma
Posts: 113
Joined: Wed Dec 03, 2014 6:46 am

Re: New mini UPS hat for our Raspberry Pi

Mon Apr 24, 2017 10:07 am

Thats way too expensive when it doesnt bring anything new except the UPS. Theres a lot of UPS's around for cheaper than this "maybe never completing kickstarter". Sorry dude.

One example: http://www.piups.net/

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xamal
Posts: 56
Joined: Wed Apr 19, 2017 1:42 pm
Location: A Coruna, Spain
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Re: New mini UPS hat for our Raspberry Pi

Mon Apr 24, 2017 11:43 am

Thank you. I appreciate your comments.

Before I decided to create this hat, obviously I was looking for a UPS solution that matches my needs. As you said, there are a lot of solutions, but I couldn't find any with integrated batteries (except one, with a higher price). All I found had a separated case for batteries (as the example you indicate) and many of them were only spare batteries, without any control (when batteries charge was low, RPi turned off abruptly). That's exactly what I didn't want.

About the price, yes. It is not cheap. When I planned the price list, my objective was not exceed 20€ per hat, but it was impossible for the quantity I can handle. Anyway, all UPS hats I found have a similar price, and without batteries (as the example you indicate). I'm not saying they do not exist. I'm just saying that I did not find any.

In summary: if you are looking for a secondary power supply, maybe this is not your best solution, because it is not designed to hold a lot of minutes or hours. If your needs are a system that avoids an unexpected shutdown and compact enough to fit all the components -battery included- in a small case, this is a good solution.
Ongelma wrote:"maybe never completing kickstarter"
If I reach the objective, the hat will be made, 100% sure. All the hard work -design, programming and tests- was made. The money I'll get is to ensure the fabrication costs. As I explain in the project description, if the objective is reached I plan to make a minor changes, like further reduce the size and move the USB connector.

In fact, you have given me to think, and I'm going to study the posiblility to fit this hat into the "official" RPi case. The measures fits. I'll check what can I do with GPIO port.

Best,
Francisco Dominguez
Xamal.es

paulv
Posts: 558
Joined: Tue Jan 15, 2013 12:10 pm
Location: Netherlands

Re: New mini UPS hat for our Raspberry Pi

Tue Apr 25, 2017 8:05 pm

Hi Francisco,

Nice job, there will be a market for it, I'm sure.

I have some experience designing UPS supplies for the RPI family, most of them are actually published on this forum.

The biggest hurdle is to create a booster circuit that will supply 2 Amps or more (for the Model 3), with a cell voltage as low as 3.2V. The solutions I investigated or purchased to try cannot do that, they simply fail a (dynamic) load test. It's hard to tell by the pictures you provide if the cell you use can supply 2 Amps or more for the duration you mentioned.

Can you possibly give a few pointers on how you have solved this obstacle and what the maximum current level is that your UPS supply can provide?

Many thanks,

paulv

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xamal
Posts: 56
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Location: A Coruna, Spain
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Re: New mini UPS hat for our Raspberry Pi

Wed Apr 26, 2017 11:54 am

Thank you paulv.

About the booster circuit, you are right!!! It's a headache!!!. My first approach was a LM2577. The problem is that it works from 3.5V, too close for LiPo batteries. So, in a RPi3 if the load was a little high (for example, executing an "apt-get install xxx", from WiFi writting in SD), the RPi stopped to work.

My solution was the MIC2876 boost regulator (you can buy in Microchip Direct). The main problem is the size!!! (UDFN, 2x2mm, 8 pin).

Best,
Francisco Dominguez
Xamal.es

paulv
Posts: 558
Joined: Tue Jan 15, 2013 12:10 pm
Location: Netherlands

Re: New mini UPS hat for our Raspberry Pi

Wed Apr 26, 2017 1:45 pm

Francisco,

Have a look here : https://flashcandy.us/products/5v-3a-up ... rd-arduino
They have used the same booster chip as you do.

From what I can gather, this is a power supply with a UPS function "only". The power can't be turned off and the RPi will not get restarted automatically when the mains returns.

paulv

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xamal
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Location: A Coruna, Spain
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Re: New mini UPS hat for our Raspberry Pi

Wed Apr 26, 2017 1:55 pm

Hi, paulv.
paulv wrote:They have used the same booster chip, there is no information if the RPi will get restarted automatically when the mains returns.
I use a small microcontroller (PIC12F1572) for this task. Keep in mind that the hat has other features, like a switch to turn on or turn off (or a hard turn off) and send to the RPi the battery voltage to monitor thru the serial port.

Best,
Francisco Dominguez,
Xamal.es

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xamal
Posts: 56
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Location: A Coruna, Spain
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Re: New mini UPS hat for our Raspberry Pi

Wed Apr 26, 2017 2:02 pm

I didn't know this UPS. It is very, very interesting. It uses a I2C communication to monitor the battery voltage instead of the serial port.

demetrice
Posts: 1
Joined: Fri Apr 28, 2017 4:55 am

Re: New mini UPS hat for our Raspberry Pi

Sat Apr 29, 2017 2:33 am

Ongelma wrote:One example: http://www.piups.net/
I don't speak German, but one issue I see from watching the video is seemingly having to physically press the momentary switch on the hat after it has discharged in order to restart the Pi. No go for embedded applications or if the Pi is in a case where this button is unreachable -- we should have power to the Pi as soon as external power is supplied without any extra steps IMO.

paulv
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Location: Netherlands

Re: New mini UPS hat for our Raspberry Pi

Sun Apr 30, 2017 8:23 am

A simple solution for a restart after a mains return can be found here:
viewtopic.php?uid=52264&f=37&t=150358&start=0

No extra controller needed, simple, reliable and inexpensive.

Enjoy!

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xamal
Posts: 56
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Location: A Coruna, Spain
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Re: New mini UPS hat for our Raspberry Pi

Mon May 08, 2017 10:12 am

Hi.

I would explain that I made a update in the proyect. As you can see in the image, I got to fit the hat into the official case.

Image

You can get more information about this update in the next URL:

https://www.kickstarter.com/projects/xa ... ts/1879416

Best,
Francisco Dominguez

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