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+The Linear ACT-34B is a gate remote.
+product page: http://www.linearcorp.com/product_detail.php?productId=867
+manual: http://www.linearcorp.com/pdf/manuals/ACT-31B_ACT-34B.pdf
+FCCID: EF4ACP00872
+The Linear ACT-31B is the same than the ACT-34B, but have only one button instead of four.
+
+The Monarch 318LIPW1K(-L) is a compatible/clone of the Linear ACT-31B.
+product page: http://www.communitycontrols.com/Product/?PID=196
+manual: http://s3.amazonaws.com/CommunityControls/PDFs/CC-Monarch-318LIPw1K.pdf
+FCCID: SU7318LIPW1K
+
+megacode
+========
+
+The value is encoded using Linear LLC MegaCode scheme.
+It uses AM/ASK/A1D pulse position for the radio signal.
+
+The radio transmission uses the 318MHz frenquency.
+The signal is encoded using Linear LLC MegaCode scheme.
+It uses AM/ASK/A1D pulse position for the radio signal.
+24 bits are transmitted:
+- 1 sync bit
+- 16 bits for the remote code
+- 4 bits for the facility code
+- 3 bits for data bits (the channel/button used)
+
+24 bursts are transmitted, plus 1 blank burst, within 150 ms.
+Each burst is a 6 ms bitframe.
+Withing the burst there is a 1 ms pulse after 2 or 5 ms.
+The blank burst does not include a pluse and is used to separate transmissions.
+The first pulse is used to synchronize and is alwasy after 5ms within the burst.
+
+sdr
+===
+
+This folder contains tools to be used with Software Defined Radio (SDR).
+
+A RTL-SDR has been used to capture the signal.
+Use *sdrangelove* to figure out the frequency.
+It is around 318MHz, but +/- 100kHz.
+Use *rtl_fm* to record the transmission:
+	rtl_fm -f 317.962M -M am megacode.pcm
+A few remote transmissions have been captured and the recordings are saved in *samples*
+
+*megacode.pcm* will have signed 16 bits little endian sample, at 24000Hz.
+Use *decode.rb* to decode this recording:
+	./decode.rb megacode.pcm
+
+To record is an opprotunistic way (someone uses an unknown remote further away), you have to tweak *rtl_fm*:
+	rtl_fm -f 317.9M:318.1M:20k -g 10 -l 700 -M am megacode.pcm
+
+pic
+===
+
+This folder contains firmwares for the transmitter and receiver microcontrollers.
+
+The PCB of the ACT-31B is the same than the ACT-34B, with only one switch out of four populated.
+It uses a PIC12C508A (SM package) microcontroller.
+This microcontroller is EEPROM based (designated by the 'C' in the name) which the PICkit 2 can't program.
+It is programmed using the test points, but only once since it's a One Time Programmable (OTP) chip.
+
+A pin compatible flash based chip can be used instead.
+Most P12FXXX are, like the PIC12F629/PIC12F675 (simplest alternative), PIC12F617 (more flash but no EEPROM), and PIC12F1840 (high end).
+They come in SN packages, which is thiner then the original SM package.
+But the pitch is the same and the pins can be soldered on the pads.
+
+The 318LIPW1K uses a re-programmable chip (flash based).
+It uses a PIC12F629 (SN package) microcontroller.
+Monarch also adversitve that the code is programmable.
+I could not find the software.
+The programming header is even present on the board.
+But the microcontroller has read protection enabled.