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2013-10-16
, 04:32
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Moderator |
Posts: 5,320 |
Thanked: 4,464 times |
Joined on Oct 2009
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#112
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2013-10-16
, 04:36
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Posts: 1,067 |
Thanked: 2,383 times |
Joined on Jan 2012
@ Finland
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#113
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The Following 12 Users Say Thank You to rainisto For This Useful Post: | ||
Daneel, jalyst, Jordi, juiceme, mikecomputing, Mikkosssss, minimos, OVK, Rauha, rcolistete, slender, TemeV |
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2013-10-16
, 04:42
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Moderator |
Posts: 5,320 |
Thanked: 4,464 times |
Joined on Oct 2009
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#114
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2013-10-16
, 05:33
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Community Council |
Posts: 4,920 |
Thanked: 12,867 times |
Joined on May 2012
@ Southerrn Finland
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#115
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However, experimenting with keyboard-building continues! I ordered some pushbuttons for a new keyboard.
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2013-10-16
, 17:37
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Posts: 3,464 |
Thanked: 5,107 times |
Joined on Feb 2010
@ Gothenburg in Sweden
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#116
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Using OH as master and phone as a slave is ideologically wrong. The device which is the "brains" of the system should be master. If the phone is slave it would always need a "master chip" at the other half, since almost all peripherals act only as a slave. Doesn't sound reasonable to me.
Multimaster solution would have a same problem, there is very little chips that can act as a multimaster. Whole multimaster thing is a little hackish IMO.
IMO phone being a master with interrupt line is the only reasonable solution, since most of i2c peripherals act only as a slave. With this solution there is whole lot of chips that can be connected directly to i2c and making other halfs is simple and fun.
Many MCUs can operate in all of the mentioned modes (master/slave/multimaster) so I'd guess phone SoCs can also do that. If the SoC handles all three modes it would be possible to leave out the interrupt line. I still think that if Jolla has done that, they have made a huge mistake.
Basically without knowing more it is not possible to choose what chip should be used. Though, no matter what the chip is going be the PCB will be about the same size, and changing the PCB for the new chip is quite simple and quick operation.
The hard part of the project is the mechanics. Since neither mechanical details aren't yet published, I don't know if there is much that can be done on that area either.
For now you can of course test different chips and their drivers, so that their strengths and weaknesses are known, when Jolla decides to publish the details.
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2013-10-16
, 19:12
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Posts: 1,067 |
Thanked: 2,383 times |
Joined on Jan 2012
@ Finland
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#117
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The Following 86 Users Say Thank You to rainisto For This Useful Post: | ||
48GX, aironeous, ajalkane, almamo, Android_808, aperles, ARJWright, Artopal, B3Punch3D, benny1967, BonoNL, Boxeri, Daneel, DeeGee, dirkvl, dizzy, DJJonosound, dommau, edgar2, ffha, ggabriel, harrihakulinen, helihyv, Hurrian, iKneaDough, isto, jalomann, jalyst, javispedro, Jordi, juiceme, Kaacz, Kabouik, kinggo, kjmackey, kulve, latency, localhost, MartinK, mattaustin, mattiviljanen, max_power, mece, mikecomputing, Mikkosssss, minimos, MINKIN2, miqu, Mitrigol, mrsellout, MSameer, nodevel, NokiaFanatic, Oblomow, OVK, P@t, pichlo, pycage, qwazix, Rauha, rcolistete, rentze, Roth, sada11, shanttu, Silwer, slender, smoothc, sponka, student4life, szopin, TemeV, thedead1440, thp, Tujutzki, v2px, vitaminj, Wallace, wnt, wolke, wred_e, xkkkx, ymb, zlatko, zlatokosi, zwer |
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2013-10-16
, 21:09
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Posts: 65 |
Thanked: 56 times |
Joined on Oct 2013
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#118
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These look pretty nice and the price's not bad
I wonder what's the mechanical feel of these buttons is like. They look really low-profile which is good when designing a kbd that is as thin as possible.
I suppose you can just make a simple keyboard with covering the button matrix with soft plastic, and have a kind of "keyless keyboard surface" with a minimal amount of tactile feedback from the buttons, however I'd like to have a bit more definitive "key-clicking" action.
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2013-10-16
, 21:57
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Posts: 339 |
Thanked: 1,623 times |
Joined on Oct 2013
@ France
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#119
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- Other half expected to work in slave mode, phone is master
- Dedicated INT GPIO (1,8V) for interrupts
Cost($) Package Voltage Max Num key led output other capabilities ADP5588 3.11 24-VFQFN + Pad 1.8 / 3 V 8x10 through unused GPIO light sensor ADP5587 2.98 24-WFQFN + Pad 1.65 / 3.6 V 8x10 through unused GPIO light sensor ADP5585 2.15 16-WFQFN + Pad 1.65 / 3.6 V 5x5 through unused GPIO pwm output if not used by keypad ADP5589 3.11 24-WFQFN + Pad 1.65 / 3.6 V 8x11 through unused GPIO pwm output if not used by keypad AT42QT1070 1.42 14-SOIC / 20-VFQFN+Pad 1.8 / 5.5 V 6 no Capacitive touch input AT42QT2160 3.2 28-VFQFN +Pad 1.8 / 5.5 V 16 no Capacitive touch input TCA6416 2.44 24-TSSOP / 24-WFQFN 1.65 / 5.5 V 16/7x7 through unused GPIO not sure there is the keypad logic in the chip... TCA6408A 2.15 16-TSSOP / 16-VFQFN+Pad 1.65 / 5.5 V 8/?x? through unused GPIO not sure there is the keypad logic in the chip... TCA8418 3.11 24-WFQFN + Pad 1.65 / 3.6 V 8x10 through unused GPIO LM8323 ? 36-BGA 1.8 V 8x13 3 pwm LM8333 2.91 32-WFQFN + Pad 2.25 / 2.9 V 8x9 4 + 1 pwm MAX7359 7.04 24-WFQFN + Pad 1.65 / 3.6 V 8x8 through unused GPIO rotary encoder interface MRP121 ? 20-QFN 1.71 / 3.6 V 12 through unused GPIO Capacitive touch input
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2013-10-17
, 09:23
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Posts: 59 |
Thanked: 66 times |
Joined on May 2007
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#120
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However, experimenting with keyboard-building continues! I ordered some pushbuttons for a new keyboard. These 4-pin buttons have the advantage that you could design a keyboard matrix on a one-sided pcb, which makes life a lot easier!
When/if Jolla confirms an interrupt-line, I will also order the tca8424 chip. I've been reading into it and it seems like a really good option given the price and rapid prototyping possibilities. The only downside so far is the lack of affordable test-sockets for qfn40.
A single-sided pcb layout would then look something like this:
Each button rests on 4 points. The sides are connected and act as a brigde. The button connects all 4 together like this:
Last edited by dirkvl; 2013-10-16 at 13:54. Reason: Added some pics