Hi,
I want to know approximately what refresh rate is required for a quadrotor in hovering state.
Also is there any limitation on refresh rate? as i can guess if the refresh rate is too high, any thing attached to the motors will torn apart (in this case the propellers).
Replies
Hello, pls witch how Acclerometer/Gyro did u achieved 400Hz frequency? MPU6050 can work maximaly on 100Hz. (I'm using it)
Make sure your I2C bus is set to 400kHz.
Hi, Update rate of Electronic Speed Controller is a bottleneck, not Accelerometer/Gyro (mems)
Acc/Gyro are just sensors, their update rate depends on the microcontroller.
Ok but MPU6050 have some clock inside becouse of the DMP unit, right?
Dont know about that, didnt used it. google it
That was worth, thanks
Suleman
The Turnigy Plush should work fine with 400 Hz.
I had some problems with the Turnigy Basic 25A using them withh 400 Hz, reducing the frequency to 350 Hz they worked well.
The hight refresh rate ist only for a faster setting transfer to the ESC's. It will not destroy your props.
Some ESC's are not able to follow so high refresh rates and will not work, or will stop from time to time.
The main reason for using a so high refresh rate is a software filter in the turnigy ESC's which is reducing fast thrust changes between two setting transfers, increasing the setting transfer rate (frequency) will bring faster response.
The ESC change response is why many/most people end up using SimonK firmware. SimonK is near instant jump which is what you want for multis but perhaps not for planes.
Im no expert but:
1. I believe 100hz is a pretty bare minimum. faster is obviously more stable (im guessing to a point!.
2. For PWM controllers there is a limit of about 450 Hz as pulse width is 2ms or less. As you aprroach 500 hz it just becomes a single high.
3. Some of te I2C ESC refreshrates are much higher.
While some ESCs dont like the faster PWM rates, I dont think the refresh rate has much risk to props etc. Even with 50hz you can still go from standing to wide open in the blink of an eye and the motors acceleration will likely be the limiting factor.
Regars
D