You can find the complete code library here on my GITHUB in which you will find the examples of IRsendDemoHelicopter.ino and IRrecvDump.ino. These and the IRremote.cpp should answer your questions. I have had it on my plan (for sometime) to implement the transmitter on an Esplora.
Below are the Micro Seconds, found at https://github.com/mpflaga/Arduino-IRremote/blob/master/IRremoteInt.h#L192
#define SYMA_UPDATE_PERIOD_CH_A 120 // 0
#define SYMA_UPDATE_PERIOD_CH_B 180 // 1
#define SYMA_HDR_MARK 2000
#define SYMA_HDR_SPACE 2000
#define SYMA_BIT_MARK 320
#define SYMA_ONE_SPACE 687
#define SYMA_ZERO_SPACE 300
and here is the pattern of bits for both the R3 and R5. I believe the R5 is the most common being in production.
union helicopter {
uint32_t dword;
struct
{
uint8_t Throttle : 7; // 0..6 0 - 127
uint8_t Channel : 1; // 7 A=0, B=1
uint8_t Pitch : 7; // 8..14 0(forward) - 63(center) 127(back)
uint8_t Pspacer : 1; // 15 na
uint8_t Yaw : 7; // 16..22 127(left) - 63(center) - 0(right)
} symaR3;
struct
{
uint8_t Trim : 7; // 0..6 127(left) - 63(center) - 0(right)
uint8_t Tspacer : 1; // 7 na
uint8_t Throttle : 7; // 8..14 0 - 127
uint8_t Channel : 1; // 15 A=0, B=1
uint8_t Pitch : 7; // 16..22 0(forward) - 63(center) 127(back)
uint8_t Pspacer : 1; // 23 na
uint8_t Yaw : 7; // 24..30 127(left) - 63(center) - 0(right)
} symaR5;
};
but it is always possible they have come out with a new pattern.