Teardown: DDC Mobile X900 | Hacker News Reader

Teardown: DDC Mobile X900

learn.sparkfun.com

88 pointsSanderMak22 comments

The thing that scares me is that as an EE in a previous life, I've seen worse things come out of one man bespoke engineering companies. One thing that sticks in my mind was a PLC replacement for some old relay logic in a factory. Rather than use a proper PLC, they glued some relays can first down to the bottom of a shielded box with hot snot and drove it with a BASIC stamp soldered to some veroboard. The whole thing packed in one day (duff relay) and I was contracted to fix it. Had to write the entire unit off and start again.

This thing was controlling what I can only describe as a giant maiming machine that would kill everyone for several feet if it went wrong.

Also one reason why a lot of "maker" contraptions scare the shit out of me. 2cm frim certain death and electrocution a lot of the time.

I wouldn't pin it all on the maker community - fake iPhone chargers are just as bad

They're not quite as terrible as the recent press makes out. Prior to the hype around this we had nearly 20 years of low quality wall wart switch mode supplies. Very few people got hurt and very few people do today. Even if they completely burn out its a low risk.

Conversely my official Lenovo T400 charger has a 90-110v AC potential between its virtual ground and true ground which occasionally gives me a tingly finger.

The maker community though have no basic electrical safety knowledge as a whole and are concerned with making it work, not making it work safely.

>The maker community though have no basic electrical safety knowledge as a whole and are concerned with making it work, not making it work safely.

Ouch. What are you basing this on? What could be done to improve the situation?

Various observations over the last few years on projects that have been posted. I'll usually flag up anything dangerous with some constructive help on why it is dangerous and how to make it safe.

Simply education. Every electronics book should open with an electrical safety section as well. Know thy enemy.

Having myself been zapped a couple of times, once due to faulty equipment and once due to idiocy on my part, I can assure you its worth the time.

> Very few people got hurt and very few people do today. Even if they completely burn out its a low risk.

Exactly; many people never seem to realise the relative risks. From [1] and [2] we find that "consumer products" (in total, and not just defective AC adapters) electrocuted approximately 50 people in the US in 2008, while in that same year 37,423 were killed in a car accident, or over 100/day on average. In light of this, is it really safer to drive to the Apple store to exchange a fake USB adapter for a real one...? Once in a while someone does get killed and it makes the news and causes panic, but the fact that these stories are so rare compared to all the other fatalities reported in the news should be an indication that the risk is almost negligible in comparison.

[1] https://www.cpsc.gov/Media/Documents/Research--Statistics/In...

[2] http://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_in...

Similarly, here is a $12 phone, again a design with only 2 main ICs, but with far fewer features (although it does have Bluetooth and an ARM...): http://www.bunniestudios.com/blog/?page_id=3107

The mention of "XCPU RISC" in the datasheet led nowhere but RDA's site, and I suspect that it's some sort of MIPS clone. They also have an ARM-based SoC, the RDA8810.

I love these Chinese crap phones. The effort spent in order to optimize the system to cut the BOM is truly astonishing.

Anyone else notice the ribs in the battery cover that were ground down by hand to make the cell fit snugly?

https://cdn.sparkfun.com/assets/learn_tutorials/2/5/1/SFE_00...

If it was strictly the BOM they were cutting, I don't think it would have had two keypads.

I can't be the only one that wants a cellphone made out of pot metal.

Phone, flashlight, and self-defense tool, all in one!

Resumé: If all you need is a cellphone with no frills and the weight and shape of a Motorola brick phone… the X900 is for you.

No frills?? Dual SIM and TWO keypads!

And a 320x240 pixels camera. That's over 70,000 pixels! Imagine how many photos you could fit on a 32gb memory card!

Here is a teardown of a $7 phone. It "looks a bit like a Nokia". The vendor applied a "Samsung" faceplate because she'd run out of all the others.

http://wiki.hacdc.org/index.php/$7_cell_phone

Wow. I had a really shitty commute this morning, and this just made my morning so much better.

This is genuinely gorgeous. The best bit is the Nokia badge!

Here is a serious question, I wonder if DCC (the phone's company) makes any money from this wonder of electronic enigneering?

What's the price of the beautiful little monster? It would help complete the awesome picture.

As mentioned in the blog post's comments, Nate paid ~ 28 USD for this. Another comment links to Alibaba Express, in case you want to buy a similar one:

http://www.aliexpress.com/item/Luxury-Mobile-Phone-X900-Flas...

What a monstrosity! I like it :)

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