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wind_sensor:meeting_minutes_mar_10_2017 [2017/03/20 06:28] snishihara [Acoustic Wind Sensor] |
wind_sensor:meeting_minutes_mar_10_2017 [2021/09/19 21:59] (current) |
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| * Tested the differences between successive measurements between a single mic and they seem pretty consistent (minus the pop in the beginning). When averaging over a large amount of samples, the result is very good. | * Tested the differences between successive measurements between a single mic and they seem pretty consistent (minus the pop in the beginning). When averaging over a large amount of samples, the result is very good. | ||
| * Attempted to measure the amount of time that each interrupt spends inside their routine by by saving the difference between the clock cycle entering the interrupt and the clock cycle when leaving the interrupt into an array. From some tests, it seems like they're both consistent, but mic2 is a bit funny. It may be because I'm reattaching mic2's interrupt after mic1, but mic1 is solid. | * Attempted to measure the amount of time that each interrupt spends inside their routine by by saving the difference between the clock cycle entering the interrupt and the clock cycle when leaving the interrupt into an array. From some tests, it seems like they're both consistent, but mic2 is a bit funny. It may be because I'm reattaching mic2's interrupt after mic1, but mic1 is solid. | ||
| - | * Instead of implementing the error-filtering code directly on the Teensy, I took some raw measurements and am going to try to filter them out using other methods first, to see if the results are good. | + | * Instead of implementing the error-filtering code directly on the Teensy, I took some raw measurements and am going to try to filter them out using other methods first, to see if the results are good. The results are below: |
| + | * {{ :wind_sensor:woohoo.png?direct&600 |}} | ||
| + | * Note that I used 100k samples, which is much more than what I'd have realistically, but this was done just to test the algorithm. As shown, the algorithm managed to get really close to the theoretical (although it should be noted that the theoretical had some error associated with it due to how we measured the distance between the mics). | ||
| * To Do: | * To Do: | ||
| * Look into using high speed ADC found here: https://forum.pjrc.com/threads/25532-ADC-library-update-now-with-support-for-Teensy-3-1. Only use a limited bit precision to try and get the highest speed. | * Look into using high speed ADC found here: https://forum.pjrc.com/threads/25532-ADC-library-update-now-with-support-for-Teensy-3-1. Only use a limited bit precision to try and get the highest speed. | ||
| * Measure the clock cycles involved with outputting a 40kHz sine wave from the DAC. If it's not too much, it may be feasible to drive it from the Teensy. | * Measure the clock cycles involved with outputting a 40kHz sine wave from the DAC. If it's not too much, it may be feasible to drive it from the Teensy. | ||
| * One possible alternative is to use thresholding to detect a wave, and then run some ADCs to determine the phase shift afterwards. | * One possible alternative is to use thresholding to detect a wave, and then run some ADCs to determine the phase shift afterwards. | ||