SmaTrig 2.1

Canon RC-1 IR remote control reverse-engineered

This article describes how the Canon RC-1 infrared remote control communicates with the camera. To figure out the protocol I used an IR photo-diode first. Because of the bad signal quality I decided then to disassemble the RC-1 and measure the IR-LED voltage directly. I used the occasion and took some pics of the circuit.

canon rc-1 disassembled canon rc-1 disassembled

To all appearances the circuit is build around a quartz-controlled microcontroller with an additional transistor to switch the IR-LED. The supply capacitor is large enough to maintain the function of the remote control for a few shots with removed batteries.

Communication protocol

To the hobbyist's delight there is no communication protocol like the RC-5 code which most TV remote controls use. The signal send by the remote control consists of two identical bursts of pulses as shown on the pics below. To distinguish between the two possible modes of operation of the Canon RC-1, the delay between the bursts is changed. The signal shown in the oscilloscope screenshots below was captured directly at the IR-LED of the circuit. The overlaid noise in some plots is due to an internal oscilloscope problem.

Timing for instant trigger mode

canon remote protocol canon remote protocol

Timing for 2s delayed trigger mode

canon remote protocol canon remote protocol

Pulse burst Timing

canon remote protocol canon remote protocol canon remote protocol

Timing and Tolerances

The signal timing of the original Canon RC-1 is listed in the table below. Having build my own remote control I could also find out the tolerance for each parameter. I used the Canon EOS 400D for testing.

Parameter Original RC-1 Tolerance
Num. of pulses 16 9 - 22
Burst frequency 32700 Hz 29800 - 35500 Hz
Delay for immediate trigger 7.33 ms 7.0 - 7.7 ms
Delay for 2 s delayed trigger 5.36 ms 5.1 - 5.7 ms

The clock frequency is very close to the standard watch crystal frequency of 32768 Hz. The experiments were made from a very short distance. I didn't test the sensitivity reduction for the deviating parameters and didn't test them in combination.


How to build a DIY Canon RC-1 clone

Comments (10)

Silvestr, that's an elegant solution!

Thanks, Luk
#10 - Luk - 12/21/2017 - 09:02
I constructed RC-1 clone based on classical four NAND gates (CMOS4093), it works fine for me. Range is 15 m with two IR LEDs in series. My circuit diagram:

Thanks for waveforms and timings

#9 - Silvestr - 12/19/2017 - 17:29
IR LED wavelength
Measured wavelength of the IR LED is about 950nm. (The IR burst is too short to measure it exactly with my spectrometer)
#8 - Q - 08/15/2013 - 13:25
#7 - rob - 05/07/2013 - 02:29
Ir protocols
There is some info about different ir protocols on my blog
#6 - Manolis Roxanas - 04/02/2012 - 05:32
Thanks to you I was able to make my own remote! Thanks! - with code and eagle files.
#5 - iwasz - 10/22/2011 - 21:17
#4 - berta - 06/16/2010 - 09:52
Thanks a lot. Thats the information I was looking for!
The internet became a dirty bitch of capitalism but it really made my day when I was searching for "canon infrared remote control protocol" at google and this information ist TOP SEARCH RESULT. There's hope yet :-)
#3 - Tyra Misoux - 01/02/2009 - 13:12
Nice info
I'm interested in these info. Thanks for your analysis.
#2 - falleaf - 11/10/2008 - 09:04
Other manufacturers
I'm interested in the protocols of other manufacturers. Please drop a line here if you have some informations.

#1 - luk - 10/20/2008 - 10:48
E-mail (Will not appear online)
To prevent automated Bots form spamming, please enter the text you see in the image below in the appropriate input box. Your comment will only be submitted if the strings match. Please ensure that your browser supports and accepts cookies, or your comment cannot be verified correctly.
This comment form is powered by GentleSource Comment Script. It can be included in PHP or HTML files and allows visitors to leave comments on the website.

Disposable Email   Temporary Email   Disposable Email