2022-12-28, 02:05 PM
it is not so simple as a specific noise level.
Yes it only needs raw sensor readings for accelerometer, gyro and compass. 20 times per second but typically 100 readings are taken every second and averaged for a lower rate of 20hz.
From my testing, magneto resistors have much much higher sensitivity than the hall sensors but worse repeatability so for this reason alone, hall sensors are preferred since they are already good enough. As for noise levels, it could even be that a particular module cross couples data lines, eg: using SPI instead of I2C has higher noise. It is difficult to say without actual testing.
What I can say.. is most, if not all imu units available will work to some degree. I would prefer better gyros above better compass/accel, but to know how well it works needs testing. On a larger heavy/slow boat it may be difficult to tell the difference if the sensors aren't as good. It really depends.
It is like asking how many megapixel camera is good enough to take a picture of a person.
Yes it only needs raw sensor readings for accelerometer, gyro and compass. 20 times per second but typically 100 readings are taken every second and averaged for a lower rate of 20hz.
From my testing, magneto resistors have much much higher sensitivity than the hall sensors but worse repeatability so for this reason alone, hall sensors are preferred since they are already good enough. As for noise levels, it could even be that a particular module cross couples data lines, eg: using SPI instead of I2C has higher noise. It is difficult to say without actual testing.
What I can say.. is most, if not all imu units available will work to some degree. I would prefer better gyros above better compass/accel, but to know how well it works needs testing. On a larger heavy/slow boat it may be difficult to tell the difference if the sensors aren't as good. It really depends.
It is like asking how many megapixel camera is good enough to take a picture of a person.