I have a small RC helicopter that is really fun, but the only problem I have with it is the lack of range/need for line-of-sight when operating it because the controller is based on IR signals. The controller has 3 IR LEDs and the helicopter has what looks to be a 38kHz IR receiver. (The specific helicopter I’'m referring to is the Swann Micro Lightning a.k.a Syma S107)
Looking in the General Section under Wireless I see that there are some simple Tx/Rx pairs you can buy for fairly cheap (I’m referring to the 315/434MHz modules). Would I be able to hook the RF transmitter input to the signal pin on the Heli-transmitter (before the 38kHz generator) and have the RF receiver output the correct data to the input signal pin where the 38kHz IR receiver is on the Heli? I understand that that there is some degree of interference present with these frequencies but I would think IR communications should be somewhat tolerant of that. There would also be some manner of transistors or optoisolators to get the correct signal but it shouldn’t be too complex (right?).
The main problems I can see with this are:
The helicopter is powered by 1 3.7v Li-Ion cell, which is under the stated minimum operating voltage of the receiver, 5v
The signal doesn’t transmit how IR would
Can someone confirm/correct me please? Ideally I’d like to upgrade this copter with a RF link and a larger battery (if it can take the weight, although tests show it’s pretty underpowered) to be able to have even more fun with this.
You could try that, but I think the signal coming off would be specific depending on the way you intend to transmit it. Have you considered modding it with say a Teensy board that you could program yourself?
UNTEngineer:
You could try that, but I think the signal coming off would be specific depending on the way you intend to transmit it. Have you considered modding it with say a Teensy board that you could program yourself?
Would you mind clarifying what you mean? From what I gather the RC control and helicopter are just a 1 way signal and since I can see a 38kHz receiver I should just be able to replace the IR protocol with an RF one. The mainboard has gyros and motor controllers that I’d rather not rebuild, and adding too much weight would put a lot of strain on the motors.
aEx155:
Would I be able to hook the RF transmitter input to the signal pin on the Heli-transmitter (before the 38kHz generator) and have the RF receiver output the correct data to the input signal pin where the 38kHz IR receiver is on the Heli?
The RF modules you're thinking of using might be able to be made to work but I'm not sure you can just use the signal to the IR transmitter to do it. First that signal may be wrong voltage levels, assuming it's digital to start with. Then I'll guess the data is in a packet of some sort, with packets transmitted infrequently. The RF receiver can be very noisy in this environment. With no constant data stream, it will be spitting out random bits, which your heli might not like. I don't know what you have for test equipment but I'd start by looking at that modulating signal in the existing transmitter and see what charcteristics it has. Maybe with a little adaptation you can get what you want.
I don’t have a signal analyzer, but I’m sure I can figure out something with a sound card or audio “analysis” or something. I’m pretty sure it is digital since it has to be outputting a 38kHz signal for the receiver on the helicopter. Hopefully the board will be tolerant of some noise.