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megacode [2014/12/28 19:49] – restructure kingkevinmegacode [2024/01/07 17:49] (current) – external edit 127.0.0.1
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 The [[http://www.linearcorp.com/|Linear]] [[http://www.linearcorp.com/radio_control.php|remote control]] solution from the [[http://www.linearcorp.com/radio_control.php#megacode|MegaCode series]] was used in the facility complex I was living for a short while, and I wanted to know how secure it is. Thus I reverse engineered it. The [[http://www.linearcorp.com/|Linear]] [[http://www.linearcorp.com/radio_control.php|remote control]] solution from the [[http://www.linearcorp.com/radio_control.php#megacode|MegaCode series]] was used in the facility complex I was living for a short while, and I wanted to know how secure it is. Thus I reverse engineered it.
  
 +At [[https://events.ccc.de/congress/2014/Fahrplan/events/6462.html|31c3]] I gave a [[https://media.ccc.de/browse/congress/2014/31c3_-_6462_-_en_-_saal_2_-_201412292245_-_megacode_to_facility_gates_-_kevin_redon.html#video|short talk]] about how to clone and record codes.
 In [[https://www.cuvoodoo.info/?post_type=podcast&p=69|episode #004]] I presented how the transmitting part works, and how to clone the radio remote controls. In [[https://www.cuvoodoo.info/?post_type=podcast&p=41|episode #005]] I presented how the receiving part works, so to record codes and analyze them. In [[https://www.cuvoodoo.info/?post_type=podcast&p=69|episode #004]] I presented how the transmitting part works, and how to clone the radio remote controls. In [[https://www.cuvoodoo.info/?post_type=podcast&p=41|episode #005]] I presented how the receiving part works, so to record codes and analyze them.
  
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 The first bit frame is used as sync frame and is always a 1. The first bit frame is used as sync frame and is always a 1.
 It is followed by 20 system code bits and 3 data bits. It is followed by 20 system code bits and 3 data bits.
 +
 +===== software defined radio =====
 +
 +This signal can be recorded using a software defined radio (SDR).
 +I used the inexpensive USB DVB stick [[https://sdr.osmocom.org/trac/wiki/rtl-sdr|RTL-SDR]].
 +
 +First find the exact frequency at which the remote transmits using an FFT software, such as [[https://sdr.osmocom.org/trac/wiki/sdrangelove|sdrangelove]].
 +Use this frequency to record and demodulate the signal using [[https://sdr.osmocom.org/trac/wiki/rtl-sdr|rtl_fm]]:
 +<code>
 +rtl_fm -f 317.962M -M am megacode.pcm
 +</code>
 +The recorded data can be view in audio editing tools such as [[http://audacity.sourceforge.net/|audacity]] by importing it as raw data, 24kHz, mono, 16 bits little endian.
 +
 +The code can also be extracted using [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/sdr/decode.rb|decode.rb]]
 +<code>
 +./decode.rb megacode.pcm
 +</code>
 +This decodes the transmissions and lists the 3 bytes values.
 +<code>
 +# egdes: 0
 +# pulses: 0
 +# groups: 1 (1)
 +# transmissions: 0
 +# values: 0
 +# egdes: 1822
 +# pulses: 167
 +# groups: 9 (24, 24, 23, 13, 10, 24, 24, 24, 1)
 +# transmissions: 5
 +# values: 5
 +values: 
 +- value: 13178818 (0xc917c2), system code: 598776 (0x922f8), databits: 2 (0x2)
 +- value: 13178818 (0xc917c2), system code: 598776 (0x922f8), databits: 2 (0x2)
 +- value: 13178818 (0xc917c2), system code: 598776 (0x922f8), databits: 2 (0x2)
 +- value: 13178818 (0xc917c2), system code: 598776 (0x922f8), databits: 2 (0x2)
 +- value: 13178818 (0xc917c2), system code: 598776 (0x922f8), databits: 2 (0x2)
 +</code>
 +
 +===== transmitting =====
 +
 +==== 318LIPW1K ====
 +
 +The 318LIPW1K can be flashed using a PICkit2 micro-controller.
 +The {{:megacode:318lipw1k_schematic.pdf|schematic}} describes how the micro-controller is connected.
 +
 +A pin header can be soldered on the board:
 +
 +{{:megacode:318lipw1k-header2.jpg?250|}}
 +{{:megacode:318lipw1k-header1.jpg?250|}}
 +{{:megacode:318lipw1k-header3.jpg?250|}}
 +
 +The firmware is available in [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/pic/318LPW1K-L|git]].
 +You can define the code to transmit in [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/pic/318LPW1K-L/eeprom.asm|EEPROM]].
 +
 +==== ACT-34B ====
 +
 +I de-soldered the PIC12F508A micro-controller and replaced it with a pin compatible (slimmer) PIC12F1840:
 +
 +{{:megacode:act34b-replace1.jpg?250|}}
 +{{:megacode:act34b-replace2.jpg?250|}}
 +{{:megacode:act34b-replace3.jpg?250|}}
 +
 +The firmware is available in [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/pic/ACT-34B|git]].
 +The two right buttons are used to send codes defined in the source.
 +I planned to use the two left buttons to brute force codes but did not finish the implementation.
 +
 +===== receiving =====
 +
 +==== MDR ====
 +
 +I de-soldered the PIC16C54A micro-controller and replaced it with a pin compatible PIC16F1847:
 +
 +{{:megacode:mdr-replace1.jpg?250|}}
 +{{:megacode:mdr-replace2.jpg?250|}}
 +{{:megacode:mdr-replace3.jpg?250|}}
 +
 +The {{:megacode:mdr_schematic.pdf|schematic}} describes how the micro-controller is connected.
 +
 +The firmware receiving and recording codes is available in [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/pic/MDR|git]].
 +How it works and how to use it further is described in the [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/README.md|README]].
 +All codes are read out over I²C when the board is powered up.
 +They can be recorded/transferred on the PC using a logic analyzer.
 +
 +The original way the codes are recorded by the device in the EEPROM is described in the [[https://git.cuvoodoo.info/kingkevin/megacode/src/branch/master/README.md|README]]
 +==== MDR-U ====
 +
 +The MDR-U is basically the same as the MDR.
 +The board is different, but the peripheral and connections around the micro-controller.
 +It uses more surface mount components.
 +It is powered through the mains (CAUTION: neutral is used as 0V).
 +
 +Same as for the MDR, I de-soldered the PIC16C54A micro-controller and replaced it with a pin compatible PIC16F1847 (SOIC version).
 +The firmware is the same as the MDR.
 +
 +==== RF module ====
 +
 +aaronsp777 [[https://github.com/aaronsp777/megadecoder|implemented a receiver]] using a generic 315 MHz module, and an Arduino.
megacode.1419796150.txt.gz · Last modified: 2024/01/07 17:49 (external edit)