150
edits
Lena/Sep 2016: Difference between revisions
Jump to navigation
Jump to search
→09/22/2016
|
Thad also proposed to increase amplitude of the calibration chirp at higher frequencies in order to have a better S/N for higher frequencies. I think it would be easier to increase the duration of the chirp at these frequencies, because the amplitude is already fairly close to the maximum.
== 09/23/2016 ==
Looking for the source of the bug where the magnetometer output jumps before outputting the calibration chirp. This results in the chirps not being at the same DC level, and sometimes going out of range.
We (I and Zach) are thinking that this might be because there is some random voltage on the Z-mode outputs while the chirps are running. I connected the FPGA outputs to the scope to see what they are outputting. I also recompiled the FPGA firmware to make all 4xint16 ↔ int64 converters compiled as pre-allocated clones, because I thought that maybe the pool of them wasn't large enough for the FPGA to function.
I don't see any DC offset on the Z-mode outputs. The chirps are always output without the DC offset, but sometimes after the VI finishes the chirp voltage is set to some DC level. It happens once in 2-3 runs, and the voltage is proportional to the amplitude of the chirp. I think it's because the "Set AO to Zero" VI is not doing that, and the DC level is a part of the next chirp.
| |||