Monday, January 21, 2013

Chinese electronics recycle fun or what's inside gsm to landline phone terminal

Here we go. I have a simple gsm terminal for landline phones, so I can call from regular analog phones through gsm network. I'm using it in low signal area with external antenna.
So one day I decided to look what's inside of it. I was thinking there would be some kind of gsm modem inside and analog support electronics etc. But found some interesting stuff.
Here how this thing looks, nothing important just grey box with gold antenna output sma socket.

Now let's take a look inside:

Yes, it is a gsm cell phone pcb inside! With phone battery for backup power. This thing is powered by nuvoTon W78E052DDG mcu. Which has 80C51(52) core. Never heared of them yet, but they make Cortex-M0 mcu and other ARMs too. I guess it is connected to the phones serial port.


Wires soldered directly to pcb connector.


Looks like Nokia or SE connector to me.


Wires soldered directly to phone external connector.
Phone pcb screwed to terminal housing posts, so this housing is made for this particular phone pcb on purporse. It means some kind of cellphones recycling =) Chips on phone pcb has date codes leading to 1999.


Wires soldered to the phones sim socket leads to a new sim socket on bottom side of terminal main pcb.


Some unknown chip under pcb.


Here must be some know-how, otherwise I don't know why they sand those chips markings.


LCD board glued in place =) This LCD board is connected through serial data line, may easily be reused. There is a black blob lcd controller on pcb.


LCD itself actually has a good contrast.

I had used a cell phone as wireless terminal to send sms alerts. But I never though this would be used in actual manufacturing =)

Update: as requested I pictured main pcb bottom side:


27 comments:

  1. looks like the old nokia business level 6xxx series board to me.

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  2. I'd guess the phone PCB is from a Nokia 6150 SAT: similar connector and a place for the mic on the bottom, infrared port and external antenna connector on the top, and SIM-slot is above the battery connectors. Regular 6150 (and 6110, 5110, etc.) had the SIM-slot under a battery, 6150 SAT had it in that different place. I'm not sure of different country and network variants though.

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  3. hey can you post a photo of the undersite from the main board?

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  4. This happens in manufacturing more than you'd think. Devices like cell phones require a lot of expensive engineering and testing for regulatory compliance. By including an existing product, they can bypass a lot of those requirements. The phone boards were likely purchased in bulk from the manufacturer instead of taken out of recycled phones. That would explain why the case was designed around the specific phone model.

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  5. The PCB looks an awful lot like my old Nokia 6210.
    Complete with the IR diodes on top and all.

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  6. Aww, that's so cute. Don't you just love those chinese manufactures ? :-)

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  7. I believe he cell is a nokia 6150, not 100% sure but reasonably.

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  8. I would bet it's a Nokia 6210/6310!

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  9. I am not that surprised. 15 years ago I was working for a wireless phone company on a project that created a PBX sort of thing from wireless phones. All the radios were basically lifted from existing fixed wireless hardware, with other circuitry added to multiplex those across 72 landlines. When existing hardware can do stuff pretty cheap, why reinvent?

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  10. Just to let you know, you got featured by Hack a Day and someone pointed out it should be the 6150:
    http://hackaday.com/2013/01/22/gsm-to-landline-box-has-a-creatively-soldered-cellphone-inside/comment-page-1/#comment-944886

    Also your captcha is pretty hard to guess.

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    Replies
    1. yea, it's a blogger captcha, actually you pass it good, I saw you made many identical comments =) I was away so was not able to moderate.

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  11. Heh.. Recycling at its best! Maybe they got a job lot of like 100K of those boards from bankrupt stock and set to building them into their product?
    I have heard of Nokia colour displays being upcycled into picture frames before, and some of the more recent batteries have showed up converted into model plane packs as a 3S1P as they are cheaper than Lipos.

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  12. in case you wanted to know ... the cellphone was a nokia 6210 or 6310i

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  13. Any idea what the little module PCB, the black one, with "A-TECH" does? It looks like something the "manufacturer" bought-in separately, rather than soldered himself from bits he found in someone's dustbin.

    It really is amazing the complexity of stuff seemingly knocked up by Chinese kids in their garages. Simple stuff I can understand, but this seems like it took a lot of development. Unless it's just pirated from a commercial design.,

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    Replies
    1. As I can see on pcb traces it is connected to phone sockets and mcu, so must
      be some output drivers or mixing tone output.

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    2. If its to the phone socket, my best guess is that it is a DTMF Touch Tone converter. It listens for the touch tones and converts it into numbers, to send to perhaps a serial line to the microcontroller.

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    3. yea probably, because this thing is configured by using buttons on the phone

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    4. DTMF is a good guess.
      I wonder about the huge inductor, probably some part of a DC-DC converter. Probably for the ring signal.

      My guess is that it is the whole phone line driver. And probably also DTMF, because that wimpy 8051 probably could not do that.

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    5. Hello to all,

      The black pcb with E-Tech printed is a slic unit as used in PABX's and the white lcd module is a caller id unit.

      Regards,
      Ali

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  14. Looks like a Nokia 6110 board to me. I had one a while ago and used to pull it apart just to marvel at the amazing tech inside (I was a very curious kid)... Amazing set up really, but in many ways this is a really good thing. Think of it as recycling older tech to be used for todays needs.

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  15. The vertical SIP pcb probably generates the standard landline phone signals like dial tone, current loop and ringing voltage.

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  16. By the looks of it, this is Nokia 6150 (NSM–1NY). Fourth picture shows probably connection for keypad signals. And sixth picture, handsfree connections for calls (pinout @ http://pinouts.ru/CellularPhones-Nokia/nokia_5110_6110_pinout.shtml ).
    And it seems they used Nokia 5110 SIM card holder too. That's recycling :D

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  17. I don't recognise this apple's product. :-)

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  18. http://www.ebay.com/itm/New-12V-Fixed-Cellular-Wireless-Terminal-Unit-Dual-Band-GSM-Gateway-900-1800-/251211262527?pt=LH_DefaultDomain_0&hash=item3a7d5baa3f

    Same as this?

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  19. Good Job , Very Help full to understand GSM terminal Thanks....

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