2017-11-29, 10:23 PM
Let me clear this up.
I initially used the 9250, but when I looked to order more mpu I could only get the 9255. I could no longer find the 9250.
The differences between the two are irrelevant for openplotter, so either is technically capable of the same thing for what we are doing.
Someone had basically copied the 9250 code to make the 9255 work changing only the part where it checks the id, I merged this fork into mine.
The code was very inefficient because it didn't use the internal fifo for the compass, and actually gave wrong readings (by mixing high and low bytes between two different samples sometimes possible) in some cases at higher sample rates
I fixed both these issues reducing cpu to 1/10th what it was, while giving always the right readings, but I only bothered to do it for the mpu9255 assuming the 9250 was being phased out..
So as it stands, right now, in openplotter, the 9255 is using my improved driver, and the 9250 the old code. It would be trivial to either copy the 9255 changes back to the 9250, or better yet, to just handle both by a single driver that accepts either id. I will probably try to do this fairly soon, I didn't realize anyone cared about the 9250.
I initially used the 9250, but when I looked to order more mpu I could only get the 9255. I could no longer find the 9250.
The differences between the two are irrelevant for openplotter, so either is technically capable of the same thing for what we are doing.
Someone had basically copied the 9250 code to make the 9255 work changing only the part where it checks the id, I merged this fork into mine.
The code was very inefficient because it didn't use the internal fifo for the compass, and actually gave wrong readings (by mixing high and low bytes between two different samples sometimes possible) in some cases at higher sample rates
I fixed both these issues reducing cpu to 1/10th what it was, while giving always the right readings, but I only bothered to do it for the mpu9255 assuming the 9250 was being phased out..
So as it stands, right now, in openplotter, the 9255 is using my improved driver, and the 9250 the old code. It would be trivial to either copy the 9255 changes back to the 9250, or better yet, to just handle both by a single driver that accepts either id. I will probably try to do this fairly soon, I didn't realize anyone cared about the 9250.