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wind_sensor:meeting_minutes_apr_14_2017 [2017/04/13 03:06] mwu |
wind_sensor:meeting_minutes_apr_14_2017 [2017/04/15 07:19] mwu [Ultrasonic Wind Sensor] |
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| * We then decided to test it with our voltage comparator set at 0V, and it gave us much better results (see below). | * We then decided to test it with our voltage comparator set at 0V, and it gave us much better results (see below). | ||
| * {{ :wind_sensor:zcd-comparator.jpg?direct&600 |}} | * {{ :wind_sensor:zcd-comparator.jpg?direct&600 |}} | ||
| - | * Delay 12.5us using nops: | ||
| - | * Not very reliable, a better approach would be to try and modify the timer's prescaler and initial value to achieve a 12.5us trigger. | ||
| * Receiver response when sending just 1 pulse: | * Receiver response when sending just 1 pulse: | ||
| + | * I had initially thought that sending just 1 pulse might be a good idea if there was a small recovery period (for the receiver to settle down), but since below shows a relatively long recovery period, it seems like the original plan of sending 10 pulses is better. | ||
| * Sending just a single pulse through the emitter still causes a relatively long received signal. Also, there is an audible frequency (~3kHz) coming from the emitter | * Sending just a single pulse through the emitter still causes a relatively long received signal. Also, there is an audible frequency (~3kHz) coming from the emitter | ||
| * {{ :wind_sensor:single-pulse.jpg?direct&600 |}} | * {{ :wind_sensor:single-pulse.jpg?direct&600 |}} | ||
| Line 23: | Line 22: | ||
| * Delay vs. Timer: | * Delay vs. Timer: | ||
| * The Timer was more precise and accurate whereas the delay had some relatively large fluctuations ~8%. | * The Timer was more precise and accurate whereas the delay had some relatively large fluctuations ~8%. | ||
| - | * TO Do: | + | * Delay 12.5us using nops: |
| + | * Not very reliable, a better approach would be to try and modify the timer's prescaler and initial value to achieve a 12.5us trigger. | ||
| + | * Modified program to utilize a Timer to send the pulses rather than a for loop and delays. Makes the frequency more stable. See pulse generation below: | ||
| + | * {{ :wind_sensor:timer_pulse_generation.jpg?direct&600 |}} | ||
| + | * Added an array to keep track of emitter times. Tested the times and they are pretty consistent. Moved circuit elements onto one board. Working on integrating transducers with receiver code. | ||
| + | * {{ :wind_sensor:circuit1.jpg?direct&600 |}} | ||
| + | * To Do: | ||
| + | * Continue working on integrating zero crossing detector with program. | ||