Reverse Engineering A Syma 107 Toy Helicopter IR Protocol

Half the fun of buying toys for your kids is getting your hands on them when they no longer play with them. [Kerry Wong] seems to be in this boat. He bought a Syma S107G helicopter for his son. The flying toy is IR controlled and he reverse engineered the protocol it uses. This isn’t the first time we’ve seen this type of thing with the toy. In fact, we already know the protocol has been sniffed and there is even a jammer project floating around out there. But we took a good look at this because of what you can learn from [Kerry’s] process.

He starts by connecting an IR photo diode to his oscilloscope. This gave him the timing between commands and allowed him to verify that the signals are encoded in a 38 kHz carrier signal. He then switched over to an IR module designed to demodulate this frequency. From there he captures and graphs all of the possible control configuration, establishing a timing and command set for the device. He finishes it off by building a replacement controller based on an Arduino. You can see a video of that hardware after the break.

9 thoughts on “Reverse Engineering A Syma 107 Toy Helicopter IR Protocol

    1. To do that you also need feedback about position and speed and angle and all that. But what else would you need to do the whole effort for really?

      And when he claims the tail rotor is ‘to lower and raise the tail’ I think he has a long way to go before he has it under control :)

      1. The tail rotor is mounted with it’s axis vertical, not like a normal helicopter (axis horizontal).

        It is indeed used to raise and lower the tail relative to the nose, ie, to alter the pitch and therefore induce forward or reverse motion.

        It is a coaxial helicopter, it does not require a torque cancelling tail rotor (or blower), yaw is controlled simply by altering the rotational speed difference between the upper and lower coaxial rotors (taking advantage of the torque).

        Roll is not implemented in these toys.

      2. This helicopter has two counter rotating main blades which act to lift and/or rotate the helicopter. The tail rotor is positioned to raise or lower the tail thereby moving the helicopter forwards or backwards. Is isn’t functioning like a typical helicopter.

      3. not really that’s what the tail rotor is really for from the factory be-leave it or not just looking at the vid the only thing change is the remote the chopper is factory

        all they have to do is get the hang of the controls

        i have the same hilly

  1. I’d like to see the works from some one of these little helis hacked into the copter part of an old Vertibird toy.

    Why? To free the Vertibird from its base for truly free flying fun.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.