[IMU] acquisition frequency

siteswapjuggler / smartball-firmware

Smartball ESP8266 firmware

GNU General Public License v3.0

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[IMU] acquisition frequency #11

Open siteswapjuggler opened 4 years ago

siteswapjuggler commented 4 years ago

IMU refresh rate is set to 142.85 Hz a value probably choosen to slower the WiFi data transmission but I could probably go higher. I should take care of two limits :

the necessay time to process IMU and its filters which is about 1800 µs
the max refresh rate of the IMU chipset
sensor update should not be at the same rate as the stream sending

Adding a IMU settings :

refresh rate at 50 Hz, 100 Hz or full speed (this could use a send rate divider and a data bufferisation)

siteswapjuggler commented 4 years ago

The chipset sample rate is 1kHz in most case and depends on a DLPF filter which I set manually in the library. Sources:

Accelerometer Data Rates and Bandwidths (p15 of MPU Register Map v1.4)
Register 26 – Configuration (p12/13 of MPU Register Map v1.4)

What I need to know is the IMU filter processing time to get a better idea of the maximum sample rate I will be able to use.

siteswapjuggler commented 4 years ago

Seems like 150 Hz is a good compromise