Author Topic: Help me reverse-eng a capacitive FC660C  (Read 45402 times)

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Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #50 on: Mon, 17 March 2014, 20:46:54 »
Hi,
I just got a leopold fc660c just sole purpose of modding (alternate controller and) , and making it a super keyboard(eventually bluetooth). I was IMing hasu and he pointed me to this thread which I am really happy to find.
I have gotten my keyboard (infact I am typing on it right now!) and I will start modding it on wednesday (when I get my multimeter EXtec Ex330 and solder iron ).
I am not an electronics major , but I still understand the basics from a class in undergrad ( I am a computer science major).
My question is can I proceed with just the multimeter I have or do I need to get a logic analyzer or any other equipment and if yes then what? Also should I open up a new thread or continue on this one?
Thanks in advance
Mohit

Offline dustinhxc

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Re: Help me reverse-eng a capacitive FC660C
« Reply #51 on: Mon, 17 March 2014, 21:15:48 »
Oh wow my FC660C is my end game board, love this damn thing. Interested to find out more about the PCB.

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #52 on: Mon, 17 March 2014, 23:26:16 »
Anyway, keep tracing! But don't bother tracing the matrix, do that with software :D

Soarer Does any framework support this? I would assume it would be something like you connect all the controller cables to the pcb and then press all the keys and then the firmware would see what signals have been sent?
Correct me if I am wrong

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #53 on: Tue, 18 March 2014, 00:45:44 »
mohitleo9, welcome to Geekhack.

Logic Analyzer with I2C protocol decoder is desirable. You will have to know 1)how the digital pot works on I2C bus and 2)how original controller scans keyboard matrix. Without Analyzer all you can do is speculation and trial-and-error loop. It will be very time consuming job. Trade-off between time and money here.
I use ZEROPLUS Logic cube but you may want cheaper and open source one like Bus Pirate or Open Bench, though I don't know about those.

After that I'd recommend to get Oscilloscope if you can afford. It is not needed during everything goes well but when in trouble you will appreciate it. This is not essential to this project, just optional.
I have Rigol DS1052E and it was the best option for a newbie several years ago, I don't know at the current.

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #54 on: Tue, 18 March 2014, 02:09:06 »
I found specs for the i2c protocol of the digital potentiometer but I really didn't understand a thing.

I'll try with a Logic Analyzer, thanks for the suggestions hasu. Do you know this http://www.saleae.com/ ?

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #55 on: Tue, 18 March 2014, 02:56:20 »
I hear good reputitions about saleae in places. I believe it works well for this job. It has good probe clips and its software looks clean and user friendly. But I don't know whether its price is reasonable in comparison with other options.

And you may want to check Dave's review. I don't watch this thoroughly.

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #56 on: Tue, 18 March 2014, 03:06:54 »
thank you hasu!

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #57 on: Tue, 18 March 2014, 09:57:16 »
Thanks Hasu for the recommendations, I will get one as it seems like a useful device!
Also Matt could you post the link for the potentiometer , I couldn't find it

Offline mkawa

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Re: Help me reverse-eng a capacitive FC660C
« Reply #58 on: Thu, 20 March 2014, 09:50:31 »
yah, dave likes the salaes. you're going to need analog readout as well. the rigol 1052e is a good deal, since you can hack it into a 1052d. the rigols in general are kind of lazy engineering in that they just take the higher end devices and software cripple them to get the lower end devices. nearly every low-end model has been hacked, usually due to entropy bugs, sometimes because it's just so damned obvious. http://poke152.blogspot.com/2013/07/riglol.html

google riglol and eevblog rigol

for high precision stuff i bought an entry level tek DPO (as soarer and i were discussing earlier). i've got some of dangerousprototype's logic analyzer boards that will do the job for a lot of digital work, but i might pick up one of the higher end rigols anyway at some point for hardcore MSO duty.

to all the brilliant friends who have left us, and all the students who climb on their shoulders.

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #59 on: Wed, 02 April 2014, 20:44:59 »
So finally after a long wait I got the logic analyzer and got to work so the I2C data it's sending is attached , I dont understand it though .
I used salae logic analyzer for this and the data is attached in csv and logicdata format ( which can be opened with their software free to download from their site)
Please help !

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #60 on: Wed, 02 April 2014, 21:17:14 »
oh one more file that has better representation of the I2c data

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #61 on: Thu, 03 April 2014, 20:43:08 »
First I have no experience with I2C at all.
I saw your i2cdata.logicdata with Saleae software but I couldn't find likely valid I2C data.

Is this data got from Pin 12 and 13 of connector(or pin 4 and 5 of AD5258) during power up?


Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #62 on: Fri, 04 April 2014, 12:04:54 »
Hi Hasu ,
First thanks for the reply,
I connected the logic analyzer to pins 12 and 13 because the pins 4 and 5 are too small.
I looked at the I2c protocol details and found this
Acknowledge—The “ACK” is the condition under which
the master generates a 9th clock pulse on the SCL line
(for each byte) while the receiving device pulls the SDA
line low in order to signify that the last byte was received.
A “NAK” is only generated by the master; it signals the
slave that no additional data need be sent.A NAK is used
prior to a STOP to prevent the slave from driving the bus with additional data when the master is about to terminate the communication
Source http://www.analog.com/static/imported-files/application_notes/54305147357414AN686_0.pdf
and then I started looking into the data file i sends setup and write instructions like that though I am not sure what they mean yet. (I am looking into the datasheet of AD5258 to understand that).
I am gonna test it again to see if something got short-circuited and post the results.
I have ordered a cable for the connector as it is standard and really small AWG28 .

Meanwhile Please see the file attached to this post to see the I2c data(the instructions) maybe that means something ?

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #63 on: Fri, 04 April 2014, 12:09:01 »
have you recorded the data on device startup?

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #64 on: Fri, 04 April 2014, 12:24:47 »
Yes I did
It sends some kind of setup to read [U + ACK] as the first instruction

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #65 on: Fri, 04 April 2014, 12:28:32 »
hope hasu can chime in. the digital potenziometer is the only bit missing. Everything else should be already set.

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #66 on: Fri, 04 April 2014, 12:46:24 »
Yeah , I also ordered a connector with the cables attached that would really help in debugging as the pins are really small! I will do the logic test again when the cable comes just to make sure that nothing was short-circuited

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #67 on: Sat, 05 April 2014, 19:59:48 »
What I can see on the data are only '0101 0101(0x55)' and '1010 1010'(0xAA), they don't look like meaning packets to me. I think we will find packets including AD5258 address on the I2C bus.

AD5258 has one of four possible addresses according to its datasheet. Which address it uses depends on pin configuration of AD0 and AD1.

Four possible addresses of AD5258:
Code: [Select]
0011000
0011010
1001100
1001110

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #68 on: Mon, 14 April 2014, 22:15:13 »
Hi
I finally got some useful data , it turned out some wires were short circuited, so I got some custom made wires and got some good results! it was about time!
So I am attaching the data and my setup pic!
hasu I would be really thankfull if you can look at it!

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #69 on: Mon, 14 April 2014, 22:29:27 »
wait let me do a couple of more tests then you guys can see ! I will attach more results , cuz the problem is I dont' see any address data as hasu mentioned

Offline mkawa

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Re: Help me reverse-eng a capacitive FC660C
« Reply #70 on: Mon, 14 April 2014, 22:35:42 »
i've had this swapped out for two long. which two chips are talking here? the digipot and the mcu? and the digipot is slaved on the bus to the mcu?

to all the brilliant friends who have left us, and all the students who climb on their shoulders.

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #71 on: Mon, 14 April 2014, 23:00:13 »
I am tracking the data on the pins between the digipot and the controller
I basically looked at the pins of the controller which are responsible for the I2c according to http://www.digchip.com/datasheets/parts/datasheet/170/MB90F337.php
and then traced the data on the corresponding pins going out of the controller.
I really appreciate the patience ,It's a bit overwhelming for me


Offline mkawa

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Re: Help me reverse-eng a capacitive FC660C
« Reply #72 on: Mon, 14 April 2014, 23:25:46 »
this is a bit weird, because all the writes are to the same address (0xA4, which doesn't match any address on the digipot per the spec sheet) but it looks like what's happening here is that you're catching broadcasts from the secondary controllers to the MCU and also writes to the digipot (146, 137, 146, 146, ...). also, according to your decode, the packets all have the same number. decode still looks wrong to me.

to all the brilliant friends who have left us, and all the students who climb on their shoulders.

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #73 on: Mon, 14 April 2014, 23:52:05 »
this is just raw data from a few lines, and the alternate ones data lines are adjacent
does this make any sense? I m sendign this cuz I might be using the wrong lines as sda scl

Offline mkawa

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Re: Help me reverse-eng a capacitive FC660C
« Reply #74 on: Mon, 14 April 2014, 23:54:15 »
yah it makes sense but i think you're still either decoding it wrong or like you said you're snooping the wrong pins. remember to double check the endianness and byte ordering

to all the brilliant friends who have left us, and all the students who climb on their shoulders.

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #75 on: Mon, 14 April 2014, 23:54:57 »
it looks like that line 2 and 4 make sense since intial output is just noise from connecting usb ,

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #76 on: Tue, 15 April 2014, 00:03:33 »
but i have checked again and again the connection s to the digipot are channels 0 and 5 pins (12 13) and there is no usefun data there

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #77 on: Tue, 15 April 2014, 00:08:53 »
I am gonna do a few more thorough tests and post the results if nothing works out  , I will go to this microcontroller meetup in nyc and seek some help there and then post the results thanks a lot

Offline mohitleo9

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Re: Help me reverse-eng a capacitive FC660C
« Reply #78 on: Tue, 15 April 2014, 00:14:47 »
I found something intersesting , another datasheet for ad5258 http://www.datasheetcatalog.com/datasheets_pdf/A/D/5/2/AD5258.shtml
which gives more possible addresses
Device
Address
0011000 0   0
0011001 NC 0
0011010 1   0
0101001 0 NC
0101010 NC NC
0101011 1 NC
1001100 0   1
1001101 NC 1
1001110 1   1
maybe one of these might do the trick

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #79 on: Tue, 15 April 2014, 02:15:21 »
what a mess. I don't have time right now, but as soon as the Granite set GB is over I'll put my head back to this.

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #80 on: Tue, 15 April 2014, 20:32:53 »
this is just raw data from a few lines, and the alternate ones data lines are adjacent
does this make any sense? I m sendign this cuz I might be using the wrong lines as sda scl

Hmm, I could not find likely signals for I2C in both ffffiinn and 555555.logicdata. Are we seeing signal of correct pins? They are 12 and 13 pin of connector in controller PCB(not keyswitch PCB), right? And correct ground will be needed to capture signal. Forgive me for silly question.

This figure uses pin number in controller PCB. And we are using this number scheme, right?


Note that pin numbers are reverse between keyswtich PCB and controller PCB.
http://geekhack.org/index.php?topic=54222.msg1214286#msg1214286

Offline mkawa

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Re: Help me reverse-eng a capacitive FC660C
« Reply #81 on: Tue, 15 April 2014, 22:01:18 »
i suspect the pins are reversed. it looks like the backside of both PCBs in that picture with 1 going to 20 etc

to all the brilliant friends who have left us, and all the students who climb on their shoulders.

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #82 on: Wed, 16 April 2014, 01:21:13 »
i suspect the pins are reversed. it looks like the backside of both PCBs in that picture with 1 going to 20 etc

yes, guys. The pins in the pictures are reversed because my header goes from the PCB to the daughter and I need them in the order they are printed on the daughter board, not on the PCB. The pins on the PCB are simply numbered from right to left.

The potenziometer pins are 8-9 which correspond to 13-12 in the schema above. Sorry for the mess but it was easier for me this way.
« Last Edit: Wed, 16 April 2014, 01:25:22 by Matt3o »

Offline lf

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Re: Help me reverse-eng a capacitive FC660C
« Reply #83 on: Sat, 21 June 2014, 15:17:17 »
Has anyone contacted Leopold and asked if they would just release this information? It can't hurt to ask, right?

Any serious copycats can reverse engineer the board anyways.

Offline lf

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Re: Help me reverse-eng a capacitive FC660C
« Reply #84 on: Sat, 21 June 2014, 15:27:03 »
Also, hello! I am new here.

Is there anything I can do to help this effort? I have a FC600C in the mail.

Offline dorkvader

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Re: Help me reverse-eng a capacitive FC660C
« Reply #85 on: Sun, 22 June 2014, 17:13:01 »
Has anyone contacted Leopold and asked if they would just release this information? It can't hurt to ask, right?

Any serious copycats can reverse engineer the board anyways.
We could ask I guess, but every company I've ever talked to has been very hesitant to release that sort of information.

Welcome to geekhack! You can certainly help out with this project depending on your skills (electrical / computer engineering etc ) / resources (logic analyzer, etc)

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #86 on: Fri, 11 July 2014, 03:17:38 »
I added HHKB JP support to my firmware the other day. JP has very similar chip set to FC660C, see this diagram.

Code: [Select]
    JP:
             +-----------------------------+-+-+-+-+       Vcc
             |bias control?                - - - - -       ---
             |                  3.9K*5     R R R R R        |
    +--------^+      +--------+            - - - - -        | 
    |         |      | HC4051 <0-----------|-|-|-|-|----|R|-+
    |         |capa. |    Z2  <1-----------|-|-|-|-|----|R|-+
    | TP1684  |sense |        <2-----------|-|-|-|-|----|R|-+
    |         <---+--|        <3-----------|-|-|-|-|----|R|-+
    |         |   |  |        <4-----------|-|-|-|-|----|R|-+
    |         |   ~En|        <5-----------|-|-|-|-|----|R|-+
    |         | +---->        <6-----------|-|-|-|-|----|R|-+
    |         | | |  | A B C  <7-----------|-|-|-|-|----|R|-+
    +---V---^-+ | |  +-^-^-^--+            | | | | |        |
       KEY PREV | |    | | |               | | | | |        |
        |   |   | |  +--------+            | | | | |        |
        |   |   | |  | HC4051 <8-----------|-|-|-|-|----|R|-+
        |   |   | |  |    Z3  <9-----------|-|-|-|-|----|R|-+
        |   |   | +--|        <A-----------|-|-|-|-|----|R|-+
        |   |   |    |        <B-----------|-|-|-|-|----|R|-+
        |   |   |    |        <C-----------|-|-|-|-|----|R|-+
        |   |   | ~En|        <D-----------|-|-|-|-|----|R|-+
        |   |   |  +->        <E-----------|-|-|-|-|----|R|-+
        |   |   |  | | A B C  <F-----------|-|-|-|-|----|R|-+
        |   |   |  | +-^-^-^--+        0 1 2 3 4 5 6 7  33K*8
        |   |   |  |   | | |         +-----------------+
        |   |   |  |   | | |         |      LS145      |
    Vcc |   |   |  |   | | |         +-^--^--^--^------+
    --- |   |   |  |   | | |           A  B  C  D   +-------+
     |  |   |   |  |   | | |           |  |  |  |   |       |
    1-2 3   4  14 15   5 6 7           8  9 10 11 12-13     |
    +--------------------------------------------------+    |
    |                connector                         |   ---
    +--------------------------------------------------+   GND

So I think this JP code will work for FC660C too. Though we still need to know how AD5258 should be initialzed.
https://github.com/tmk/tmk_keyboard/blob/master/keyboard/hhkb/matrix.c

And JP has land pattern for BU9831 but not installed inerestingly. Digipot seems to be not so critical for Topre TP1684 chip.

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #87 on: Fri, 11 July 2014, 03:30:27 »
thanks for the update hasu. Unfortunately I don't know how to help with the AD5258. I still miss a digital analyzer but I will probably get one soon.

Offline user888

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Re: Help me reverse-eng a capacitive FC660C
« Reply #88 on: Mon, 26 January 2015, 05:21:01 »
No new info on the reverse engineering?

Offline spfft

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Re: Help me reverse-eng a capacitive FC660C
« Reply #89 on: Thu, 17 September 2015, 10:12:25 »
Anyone get anywhere with this? I'd love to attempt the same mod.

Offline ramnes

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Re: Help me reverse-eng a capacitive FC660C
« Reply #90 on: Thu, 24 September 2015, 08:48:56 »
Matt3o, hasu, mohitleo9, mkawa, thanks for all the work here, that's pretty impressive.

I don't have a lot of skills in electronic but I have a FC660C in pieces right now.

I really would like this to happen, is there anything I can do to help?
23h18 - photekq: hhkb with silenced realforce sliders and lubricated well is
23h18 - photekq: the best switch i've used

Offline wubzorz

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Re: Help me reverse-eng a capacitive FC660C
« Reply #91 on: Mon, 09 May 2016, 06:38:59 »
Is this still being investigated (very few threads floating around for this specific board)?

From probing the AD5258 I2C lines, it doesn't appear there is any RDAC initialization happening. The wiper is set from EEPROM on supply (SDA and SCL are both high). You can measure the resistance between A/B/W pins on the potentiometer to confirm on power (~62Mohm to 43kohm).

Currently in the process of designing an alternate board for this specific KB (using a Cortex M0+ and CC2540 BLE). This thread has been of great help.

Offline ramnes

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Re: Help me reverse-eng a capacitive FC660C
« Reply #92 on: Tue, 10 May 2016, 18:19:47 »
Awesome, please keep us up to date!
23h18 - photekq: hhkb with silenced realforce sliders and lubricated well is
23h18 - photekq: the best switch i've used

Offline IonutZ

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Re: Help me reverse-eng a capacitive FC660C
« Reply #93 on: Wed, 21 December 2016, 07:20:52 »
Sorry to resurrect the dead but any luck on this? Matt3o or hasu?

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #94 on: Wed, 21 December 2016, 17:51:28 »
As wubzorz denoted the digipot is not needed to be initialized, all infomation is ready now.
You owners, it is time to place your board in peril for mod! I'm not a owner.

Offline Matt3o

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Re: Help me reverse-eng a capacitive FC660C
« Reply #95 on: Thu, 22 December 2016, 03:28:16 »
As wubzorz denoted the digipot is not needed to be initialized, all infomation is ready now.
You owners, it is time to place your board in peril for mod! I'm not a owner.

so... how would you proceed? would you start from your code for the HHKB?

Offline hasu

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Re: Help me reverse-eng a capacitive FC660C
« Reply #96 on: Thu, 22 December 2016, 06:33:02 »
Yes, I'd do that. I think you can use its timing of key scan sequence at least.
https://github.com/tmk/tmk_keyboard/blob/master/keyboard/hhkb/matrix.c#L62-L142

Offline sony

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Re: Help me reverse-eng a capacitive FC660C
« Reply #97 on: Mon, 02 January 2017, 14:25:08 »
As wubzorz denoted the digipot is not needed to be initialized, all infomation is ready now.
You owners, it is time to place your board in peril for mod! I'm not a owner.

Sounds like we're getting close. I have a 660c and access to a lot of things at my school. If you need anything probed or something, just give me detailed instructions and I can probably get it done.

Offline robotmaxtron

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Re: Help me reverse-eng a capacitive FC660C
« Reply #98 on: Tue, 03 January 2017, 21:13:57 »
Oh boy, this is really exciting.

Offline Krelbit

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Re: Help me reverse-eng a capacitive FC660C
« Reply #99 on: Sat, 07 January 2017, 13:30:00 »
Looking into the FC660C recently and this thread caught my eye. Any further development as of recently?