L3g4200D (P/N 27911) Gyroscope and R/C Helicopter

[smithdavidp]

I was in Radio Shack, Sunday, to buy a compass for my project. While looking at the Parallax display, and wondering what the budget is for this month, I saw a Gyro. I bought it, and the compass, and headed home. The thought occured to me to use it, and my old Bs2 BOE to fly my Raven 50 R/C helicopter. It is a 50 size bird so the extra weight shouldn't bother it. The question is if this is possible?. The spec sheet claims it will hold stable for all three axis. Has anyone tried this before? The Bird is 6ft long from tip of blade to tip of tail rotor. 12 inches high by 10 inches wide so there is plenty of room for the Bs2. I use Futaba servos (S3151) servos except for the tail rotor servo which uses a S9254 due to speed considerations. A total of six all together. Would the larger servos be too much for the Bs2 to handle? I use a Futaba 9CHP Super Radio. The battery used to power the receiver and servos is a Futaba NR4J 4.8 Vdc rated at 600 mAh. I'd like some feed back before I go destroying a 1700 dollar aircraft. Thanks

[Duane Degn]

This is a lot more complicated than it might appear.

First off, do you want the BS2 going to completely control the Helicopter? If so then this is way beyond the abilities of the BS2. It can't read in servo pulse and send servo pulses fast enough for more than few channels.

It take more than a 3-axis gyro to control a helicopter. The gyros drift over time and need to be re-zeroed by accelerometers. The accelerometers also can't be trusted on their own. You need some really smart software to merge the two (or more) sensor readings.

The math required of such a program would be beyond what a BS2 could prerform in between refreshing servos.

This would be very difficult to do with a Propeller. A Propeller could probably control a quadcopter, but quadcopters are more stable than normal helicopters.

The larger servos shouldn't be problem because the servos will on receive a signal from the BS2 not power.