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0.2.0 SRF05
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Rob Tillaart
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@ -6,10 +6,19 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
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and this project adheres to [Semantic Versioning](http://semver.org/).
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## [0.2.0] - 2024-01-28
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- add **float calculateSpeedOfSound(float temperature, float humidity)**
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- redo lookup table SOS temperature humidity
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- redo **float determineSpeedOfSound(float distance, uint8_t count = 64)**
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- removed the **Out** pin as it is non functional yet.
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- update readme.md
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- update examples
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----
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## [0.1.5] - 2023-11-22
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- update readme.md
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## [0.1.4] - 2023-03-15
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- add **uint32_t lastTime()**
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- changed return type **bool setCorrectionFactor()**
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@ -1,6 +1,6 @@
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MIT License
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Copyright (c) 2021-2023 Rob Tillaart
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Copyright (c) 2021-2024 Rob Tillaart
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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@ -16,15 +16,34 @@ Arduino library for the SRF05 distance sensor and compatibles.
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## Description
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The library allows to adjust to the speed of sound (sos).
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Reasons to use a different value are temperature, humidity, type of gas, composition etc.
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This library implements a API for a PING type of sensor.
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It is expected to work for quite a range of them.
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THe current version of the library only uses the SRF04 compatibility mode which uses a
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separate TRIGGER and ECHO pin.
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It does not (yet) implement the SRF05 mode in which TRIGGER and ECHO are the same.
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Default value for the speed of sound is set to 340 m/s. (~15°C)
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An important feature of this library is that it allows to adjust to the speed of sound (SOS).
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Reasons to use a different value for the speed of sound is that it varies depending on
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temperature, humidity, composition of the air, air pressure, other type of gas, etc.
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Default value for the speed of sound is set to 340 m/s. (air, ~15°C, sea level pressure)
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Since the version 0.2.0 the library has an interpolation formula to calculate the speed of sound
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given a temperature and humidity.
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The library has several ways to adjust / improve the quality of the measurements.
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E.g. by taking the average or the median of multiple readings, there will be less noise.
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This can be set with the different mode commands.
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The library allows to set a correction factor to compensate for the timing of
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the **pulseIn()** function. This has in the end the same effect as changing the
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speed of sound however it is technically more correct to keep the two separated.
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#### Effect temperature and humidity
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Several correction formulas for the speed of sound are available on the internet.
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Several correction formulas for the speed of sound are available on the internet
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to adjust the speed for temperature (°C) and humidity (%RH).
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```
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// temperature in °C
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@ -34,41 +53,58 @@ v = 20.05 * sqrt(273.16 + temperature) (m/s)
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```
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In fact humidity has an effect which increases with temperature so the formula is more complex.
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See - https://forum.arduino.cc/t/ultrasonic-sensor-to-determine-water-level/64890/12
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See discussion - https://forum.arduino.cc/t/ultrasonic-sensor-to-determine-water-level/64890/12
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Note that the speed of sound is also altered by air pressure (sea level .. high in sky)
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and wind speed. The latter is a bit compensated for, as the acoustic pulse will go one time
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"against" the wind and one time "with" the wind.
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| temp | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% | notes |
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|:----:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------|
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| -30 | 313.5 | 329.5 | 312.9 | 329.6 | 313.0 | 329.6 | 313.1 | 329.7 | 329.7 | extrapolated indication
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| -25 | 316.5 | 332.6 | 316.0 | 332.7 | 316.1 | 332.7 | 316.2 | 332.8 | 332.9 | extrapolated indication
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| -20 | 319.5 | 335.6 | 319.1 | 335.7 | 319.2 | 335.9 | 319.3 | 336.0 | 336.0 | extrapolated indication
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| -15 | 322.5 | 330.5 | 322.2 | 330.6 | 322.3 | 330.6 | 322.4 | 330.7 | 330.7 | extrapolated indication
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| -10 | 325.5 | 333.6 | 325.3 | 333.7 | 325.4 | 333.7 | 325.5 | 333.8 | 333.9 | extrapolated indication
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| -5 | 328.5 | 336.6 | 328.4 | 336.7 | 328.5 | 336.9 | 328.6 | 337.0 | 337.0 | extrapolated indication
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| 0 | 331.5 | 331.5 | 331.5 | 331.6 | 331.6 | 331.6 | 331.7 | 331.7 | 331.7 |
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| 5 | 334.5 | 334.6 | 334.6 | 334.7 | 334.7 | 334.7 | 334.8 | 334.8 | 334.9 |
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| 10 | 337.5 | 337.6 | 337.7 | 337.7 | 337.8 | 337.9 | 337.9 | 338.0 | 338.0 |
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| 15 | 340.5 | 340.6 | 340.7 | 340.8 | 340.9 | 341.0 | 341.1 | 341.2 | 341.2 |
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| 20 | 343.5 | 343.6 | 343.7 | 343.9 | 344.0 | 344.1 | 344.2 | 344.4 | 344.5 |
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| 25 | 346.4 | 346.6 | 346.8 | 347.0 | 347.1 | 347.3 | 347.5 | 347.6 | 347.8 |
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| 30 | 349.4 | 349.6 | 349.9 | 350.1 | 350.3 | 350.5 | 350.8 | 351.0 | 351.2 |
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| 35 | 352.4 | 352.6 | 353.0 | 353.2 | 353.5 | 353.7 | 354.1 | 354.4 | 354.6 | extrapolated indication
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| 40 | 355.4 | 355.6 | 356.1 | 356.3 | 356.7 | 356.9 | 357.4 | 357.8 | 358.0 | extrapolated indication
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| 45 | 358.4 | 358.6 | 359.2 | 359.4 | 359.9 | 360.1 | 360.7 | 361.2 | 361.4 | extrapolated indication
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| 50 | 361.4 | 361.6 | 362.3 | 362.5 | 363.1 | 363.3 | 364.0 | 364.6 | 364.8 | extrapolated indication
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| 55 | 364.4 | 364.6 | 365.4 | 365.6 | 366.3 | 366.5 | 367.3 | 368.0 | 368.2 | extrapolated indication
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| 60 | 367.4 | 367.6 | 368.5 | 368.7 | 369.5 | 369.7 | 370.6 | 371.4 | 371.6 | extrapolated indication
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#### Table speed of sound for temperature and humidity in air at sea level.
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(table based upon https://www.engineeringtoolbox.com/air-speed-sound-d_603.html)
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(table redone completely in 0.2.0)
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Temperature in Celsius, Humidity in %, constant pressure == 1013 mBar.
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| temp | 0% | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% | 100% |
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|:----:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|:------:|
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| -40 | 306.22 | 306.23 | 306.24 | 306.25 | 306.26 | 306.26 | 306.27 | 306.28 | 306.29 | 306.30 | 306.31 |
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| -35 | 309.49 | 309.50 | 309.50 | 309.51 | 309.52 | 309.52 | 309.53 | 309.54 | 309.54 | 309.55 | 309.56 |
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| -30 | 312.72 | 312.73 | 312.73 | 312.74 | 312.74 | 312.75 | 312.75 | 312.76 | 312.76 | 312.77 | 312.78 |
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| -25 | 315.92 | 315.93 | 315.93 | 315.94 | 315.94 | 315.95 | 315.95 | 315.96 | 315.96 | 315.97 | 315.98 |
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| -20 | 319.09 | 319.10 | 319.10 | 319.11 | 319.12 | 319.12 | 319.13 | 319.14 | 319.14 | 319.15 | 319.16 |
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| -15 | 322.22 | 322.23 | 322.24 | 322.25 | 322.26 | 322.27 | 322.28 | 322.29 | 322.30 | 322.31 | 322.32 |
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| -10 | 325.33 | 325.34 | 325.36 | 325.37 | 325.39 | 325.40 | 325.42 | 325.43 | 325.45 | 325.46 | 325.47 |
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| -5 | 328.40 | 328.42 | 328.44 | 328.47 | 328.49 | 328.51 | 328.53 | 328.56 | 328.58 | 328.60 | 328.62 |
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| 0 | 331.45 | 331.48 | 331.51 | 331.54 | 331.57 | 331.61 | 331.64 | 331.67 | 331.70 | 331.73 | 331.76 |
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| 5 | 334.47 | 334.52 | 334.56 | 334.61 | 334.65 | 334.70 | 334.74 | 334.79 | 334.83 | 334.88 | 334.93 |
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| 10 | 337.46 | 337.52 | 337.58 | 337.64 | 337.70 | 337.76 | 337.82 | 337.88 | 337.94 | 338.00 | 338.06 |
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| 15 | 340.43 | 340.52 | 340.61 | 340.70 | 340.79 | 340.88 | 340.97 | 341.06 | 341.15 | 341.24 | 341.33 |
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| 20 | 343.37 | 343.49 | 343.62 | 343.74 | 343.87 | 343.99 | 344.12 | 344.24 | 344.37 | 344.49 | 344.61 |
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| 25 | 346.29 | 346.46 | 346.63 | 346.80 | 346.97 | 347.14 | 347.31 | 347.48 | 347.65 | 347.82 | 347.99 |
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| 30 | 349.18 | 349.41 | 349.64 | 349.87 | 350.10 | 350.32 | 350.55 | 350.78 | 351.01 | 351.24 | 351.47 |
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| 35 | 352.04 | 352.35 | 352.65 | 352.96 | 353.27 | 353.57 | 353.88 | 354.19 | 354.49 | 354.80 | 355.11 |
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| 40 | 354.89 | 355.29 | 355.70 | 356.10 | 356.50 | 356.91 | 357.31 | 357.71 | 358.12 | 358.52 | 358.92 |
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| 45 | 357.71 | 358.24 | 358.76 | 359.29 | 359.82 | 360.34 | 360.87 | 361.40 | 361.92 | 362.45 | 362.98 |
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| 50 | 360.51 | 361.19 | 361.87 | 362.55 | 363.23 | 363.92 | 364.60 | 365.28 | 365.96 | 366.64 | 367.32 |
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| 55 | 363.29 | 364.16 | 365.04 | 365.91 | 366.78 | 367.66 | 368.53 | 369.40 | 370.28 | 371.15 | 372.02 |
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| 60 | 366.05 | 367.16 | 368.27 | 369.38 | 370.49 | 371.59 | 372.70 | 373.81 | 374.92 | 376.03 | 377.14 |
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The library has several ways to improve the quality of the measurements.
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E.g. by taking the average or the median of multiple readings.
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This can be set with the mode commands.
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**Notes on table**
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- values for 0% are calculated with ```sos = 331.45 * sqrt(1 + T/273.16); // T in Celsius```
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- values for 90% are calculated with - https://sengpielaudio.com/calculator-airpressure.htm
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- these match - https://www.engineeringtoolbox.com/air-speed-sound-d_603.html
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- the other values are linear interpolated between the 0 and 90 column (100% is extrapolated)
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- the table range is from -40 to +60 as that covers 99% of the "normal" temperatures occuring.
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The library allows to set a correction factor to compensate for the timing of
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the **pulseIn()** function. This has in the end the same effect as changing the
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speed of sound however it is technically more correct to keep the two separated.
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For temperatures under 0°C the effect of humidity goes to zero as we look how the difference
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between 90% and 0% decreases when temperature drops.
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The function **float calculateSpeedOfSound()** uses two interpolations derived from the table above.
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The function has no look-up table and uses no lookup table / RAM.
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This function returns a speed of sound with an overall error margin less than 1%, and mostly even
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lower than 0.5% compared to the numbers above.
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## Interface
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@ -85,9 +121,12 @@ It is not clear what the purpose of the OUT pin is, effectively it is not used y
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#### Configuration
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- **void setSpeedOfSound(float sos)** adjust the speed of sound.
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- **void setSpeedOfSound(float sos)** adjust the speed of sound in meters per second (m/s).
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See table above.
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- **float getSpeedOfSound()** return set value.
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The function has **no range check** and accepts even negative values.
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This will cause a negative sign in the distances which can be handy sometimes when you have
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two sensors in opposite directions.
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- **float getSpeedOfSound()** return set value (m/s)
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- **bool setCorrectionFactor(float factor = 1)** adjust the timing by a few percentage e.g. to adjust clocks.
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Typical values are between 0.95 and 1.05 to correct up to 5%.
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Should not be used to correct the speed of sound :)
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@ -108,11 +147,14 @@ count must between 3 and 15 otherwise it is clipped.
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Note: between the reads there is a delay of 1 millisecond.
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- **void setModeRunningAverage(float alpha)** use a running average algorithm
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with a weight alpha. Value for alpha depends on your application.
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Alpha must be larger than zero and smaller or equal to one. Alpha == <0..1]
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Lower alpha averages great for static distances, a higher alpha is better
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suited for changing distances.
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- **uint8_t getOperationalMode()** returns the operational mode 0..3.
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See table below.
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| operational mode | value | Notes |
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| Operational mode | Value | Notes |
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|:-------------------------|:-------:|:-------:|
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| SRF05_MODE_SINGLE | 0 | |
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| SRF05_MODE_AVERAGE | 1 | |
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@ -120,10 +162,16 @@ See table below.
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| SRF05_MODE_RUN_AVERAGE | 3 | |
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| | other | error |
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If other modi are needed, please open an issue and I see if it fits.
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Of course one can create more elaborated processing of measurements
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outside the library.
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#### Get distance
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- **uint32_t getTime()** returns distance in microseconds.
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This is the core measurement function, the next five are wrappers
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around this one.
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- **uint32_t getMillimeter()** returns distance in millimetre.
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- **float getCentimeter()** returns distance in centimetre.
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- **float getMeter()** returns distance in meter.
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@ -136,7 +184,7 @@ See table below.
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Since 0.1.4 two experimental functions are added to tune the length
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of the trigger signal.
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The idea is that shorter triggers can be used with harder surfaces
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or short distances. Longer trigger for longer distances.
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or short distances. Longer trigger thus for longer distances.
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The effects and value of adjusting trigger length needs investigation.
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Experiences are welcome.
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@ -151,17 +199,35 @@ Put the sensor at exactly 1.00 meter from a wall, and based
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upon the timing it will give an estimate for the speed of sound.
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0.1.2 version seems to be accurate within 5 %.
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- **float determineSpeedOfSound(uint16_t distance)** distance is between
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sensor and the wall - not forth and back.
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The distance is averaged over 16 measurements.
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- **float determineSpeedOfSound(float distance, uint8_t count = 64)** distance is between
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sensor and the wall, single trip, not forth and back.
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The distance is in meters, returns meters/second.
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The distance is averaged over count measurements.
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Function can be used to compensate for temperature and humidity.
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This function can be used to compensate for temperature, humidity
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or even other types of gas (e.g. N2 only)
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#### Experimental - calculateSpeedOfSound
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- **float calculateSpeedOfSound(float temperature, float humidity)**
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Calculates the speed of sound given a temperature in Celsius (-40..60)
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and relative humidity (0..100).
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The function uses an interpolation formula derived from the table above.
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This returns a speed with an error margin less than 1%, and for the most
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part it is even better than 0.5%.
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Be aware that especially humidity sensors have an accuracy, often in the
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range from two to five percent. So it won't get much better.
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#### Performance
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Assumes default speed of sound of 340 m/sec.
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Expected pulse timing.
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| distance (cm) | time (us) |
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|:-------------:|----------:|
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| 1 | 29.4 |
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@ -174,8 +240,9 @@ Assumes default speed of sound of 340 m/sec.
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| 200 | 5882.4 |
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| 300 | 8823.5 |
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| 400 | 11764.7 |
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| 500 | 14705.9 |
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to be elaborated.
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To be elaborated.
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## Operational
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@ -193,14 +260,19 @@ See examples.
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- add examples
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- DHT22 and the formula for SOS
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- add **float calcSOS(float temp, float humidity = 0)**
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- investigate effect of wind (speed of air) on the speed of sound.
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- investigate
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- should **setSpeedOfSound(float sos)** return bool if sos <=0 ?
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- value of **setTriggerLength()**
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- investigate switching between single pin (SRF05) mode and dual pin (SRF04) mode.
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- need a separate constructor.
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- investigate "guard time" between reads of 50 ms (20x /sec max).
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#### Could
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- set default SOS to an SOS from the table instead of 340.
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- function **begin(T, H)** ?
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- add example to determine the correction factor?
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- delay(1) in average configurable?
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@ -1,7 +1,7 @@
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//
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// FILE: SRF05.cpp
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// AUTHOR: Rob Tillaart
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// VERSION: 0.1.5
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// VERSION: 0.2.0
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// DATE: 2021-05-17
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// PURPOSE: Arduino library for the SRF05 distance sensor (and compatibles)
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// URL: https://github.com/RobTillaart/SRF05
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@ -14,21 +14,21 @@
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//
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// CONSTRUCTORS
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//
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SRF05::SRF05(const uint8_t trigger, const uint8_t echo, const uint8_t out)
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SRF05::SRF05(const uint8_t trigger, const uint8_t echo)
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{
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_trigger = trigger;
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_echo = echo;
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_out = out;
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_mode = 0;
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_mode = SRF05_MODE_SINGLE;
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pinMode(_trigger, OUTPUT);
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digitalWrite(_trigger, LOW);
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pinMode(_echo, INPUT);
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}
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void SRF05::setSpeedOfSound(float sos)
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void SRF05::setSpeedOfSound(float speedOfSound)
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{
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_speedOfSound = sos;
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_speedOfSound = speedOfSound;
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}
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float SRF05::getSpeedOfSound()
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@ -64,7 +64,7 @@ void SRF05::setModeSingle()
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void SRF05::setModeAverage(uint8_t count)
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{
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_mode = SRF05_MODE_AVERAGE;
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_mode = SRF05_MODE_AVERAGE;
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if (_count == 0) _count = 1;
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_count = count;
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}
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@ -81,6 +81,7 @@ void SRF05::setModeMedian(uint8_t count)
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void SRF05::setModeRunningAverage(float alpha)
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{
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_mode = SRF05_MODE_RUN_AVERAGE;
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_count = 1;
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_alpha = alpha;
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@ -135,6 +136,7 @@ uint32_t SRF05::getTime()
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_value = (1 - _alpha) * _value + _alpha * _read();
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return _value;
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}
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return 0; // should not happen
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}
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@ -169,15 +171,19 @@ float SRF05::getFeet()
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// EXPERIMENTAL
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float SRF05::determineSpeedOfSound(uint16_t distance)
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// distance in meters (single trip)
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float SRF05::determineSpeedOfSound(float distance, uint8_t count)
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{
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float sum = 0;
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for (uint16_t i = 0; i < 16; i++)
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if (count == 0) count = 1;
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while (count--)
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{
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sum += _read();
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delay(1);
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}
|
||||
float sos = (16 * 2e6) * distance / sum;
|
||||
// sos = distance travelled forth and back in micrometer
|
||||
// divided by time in microseconds.
|
||||
float sos = (count * distance * 2e6) / sum;
|
||||
return sos;
|
||||
}
|
||||
|
||||
@ -200,6 +206,23 @@ uint32_t SRF05::lastTime()
|
||||
}
|
||||
|
||||
|
||||
float SRF05::calculateSpeedOfSound(float temperature, float humidity)
|
||||
{
|
||||
// interpolate
|
||||
// column RNH = 0%, from formula.
|
||||
float sos = 331.45 * sqrt(1 + temperature/273.15);
|
||||
// column RH = 100%, interpolation from spreadsheet
|
||||
float sos_100 = 332.392083694084 + 0.683791630591631 * temperature;
|
||||
|
||||
// interpolate the humidity between these 2
|
||||
if (humidity > 0)
|
||||
{
|
||||
sos += (sos_100 - sos) * humidity * 0.01;
|
||||
}
|
||||
return sos;
|
||||
}
|
||||
|
||||
|
||||
//////////////////////////////////////////////////
|
||||
//
|
||||
// PRIVATE
|
||||
|
||||
@ -2,7 +2,7 @@
|
||||
//
|
||||
// FILE: SRF05.h
|
||||
// AUTHOR: Rob Tillaart
|
||||
// VERSION: 0.1.5
|
||||
// VERSION: 0.2.0
|
||||
// DATE: 2021-05-17
|
||||
// PURPOSE: Arduino library for SRF05 distance sensor
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
@ -10,7 +10,7 @@
|
||||
|
||||
#include "Arduino.h"
|
||||
|
||||
#define SRF05_LIB_VERSION (F("0.1.5"))
|
||||
#define SRF05_LIB_VERSION (F("0.2.0"))
|
||||
|
||||
|
||||
const uint8_t SRF05_MODE_SINGLE = 0;
|
||||
@ -22,11 +22,11 @@ const uint8_t SRF05_MODE_RUN_AVERAGE = 3;
|
||||
class SRF05
|
||||
{
|
||||
public:
|
||||
explicit SRF05(const uint8_t trigger, const uint8_t echo, const uint8_t out = 0);
|
||||
explicit SRF05(const uint8_t trigger, const uint8_t echo);
|
||||
|
||||
|
||||
// configuration
|
||||
void setSpeedOfSound(float sos = 340);
|
||||
void setSpeedOfSound(float speedOfSound = 340); // meter/sec
|
||||
float getSpeedOfSound();
|
||||
|
||||
// adjust timing
|
||||
@ -52,7 +52,11 @@ public:
|
||||
|
||||
|
||||
// Experimental - calibration
|
||||
float determineSpeedOfSound(uint16_t count);
|
||||
// The distance is averaged over 64 measurements.
|
||||
// blocks for 70-80 ms.
|
||||
// distance in meters (1 meter = 3.333 feet)
|
||||
// returns speed in m/s.
|
||||
float determineSpeedOfSound(float distance, uint8_t count = 64);
|
||||
|
||||
|
||||
// Experimental - adjust trigger length
|
||||
@ -65,18 +69,22 @@ public:
|
||||
// TIMING
|
||||
uint32_t lastTime();
|
||||
|
||||
// helper function.
|
||||
// temperature and humidity to be determined by a sensor e.g. DHT22 or SHT85
|
||||
// returned value must be set explicitly by setSpeedOfSound().
|
||||
float calculateSpeedOfSound(float temperature, float humidity);
|
||||
|
||||
|
||||
private:
|
||||
uint8_t _trigger;
|
||||
uint8_t _echo;
|
||||
uint8_t _out;
|
||||
uint8_t _mode = SRF05_MODE_SINGLE;
|
||||
uint8_t _count = 1;
|
||||
float _alpha = 1.0;
|
||||
float _value = 0;
|
||||
float _correctionFactor = 1;
|
||||
uint8_t _triggerLength = 10;
|
||||
float _speedOfSound = 340; // 20°C
|
||||
float _speedOfSound = 340; // 15°C 0%RH Sea level
|
||||
uint32_t _lastTime = 0;
|
||||
|
||||
uint32_t _read();
|
||||
|
||||
@ -0,0 +1,47 @@
|
||||
//
|
||||
// FILE: SRF05_calculateSpeedOfSound.txt
|
||||
// AUTHOR: Rob Tillaart
|
||||
// PURPOSE: demo distance sensor
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
|
||||
|
||||
#include "SRF05.h"
|
||||
|
||||
const int trigger = 7;
|
||||
const int echo = 6;
|
||||
|
||||
SRF05 SRF(trigger, echo);
|
||||
|
||||
|
||||
void setup()
|
||||
{
|
||||
Serial.begin(115200);
|
||||
Serial.println();
|
||||
Serial.println(__FILE__);
|
||||
Serial.print("SRF05_LIB_VERSION: ");
|
||||
Serial.println(SRF05_LIB_VERSION);
|
||||
Serial.println();
|
||||
|
||||
|
||||
for (int temp = -40; temp <= 60; temp += 5)
|
||||
{
|
||||
Serial.print(temp);
|
||||
Serial.print("\t");
|
||||
for (int hum = 0; hum <= 100; hum += 10)
|
||||
{
|
||||
float sos = SRF.calculateSpeedOfSound(temp, hum);
|
||||
Serial.print(sos, 2);
|
||||
Serial.print("\t");
|
||||
}
|
||||
Serial.println();
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void loop()
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
|
||||
// -- END OF FILE --
|
||||
@ -2,7 +2,6 @@
|
||||
// FILE: SRF05_demo.ino
|
||||
// AUTHOR: Rob Tillaart
|
||||
// PURPOSE: demo distance sensor
|
||||
// DATE: 2021-05-17
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
|
||||
|
||||
@ -17,7 +16,11 @@ SRF05 SRF(trigger, echo);
|
||||
void setup()
|
||||
{
|
||||
Serial.begin(115200);
|
||||
Serial.println();
|
||||
Serial.println(__FILE__);
|
||||
Serial.print("SRF05_LIB_VERSION: ");
|
||||
Serial.println(SRF05_LIB_VERSION);
|
||||
Serial.println();
|
||||
|
||||
SRF.setCorrectionFactor(1.035);
|
||||
}
|
||||
@ -41,5 +44,5 @@ void loop()
|
||||
}
|
||||
|
||||
|
||||
// -- END OF FILE --
|
||||
// -- END OF FILE --
|
||||
|
||||
|
||||
@ -2,7 +2,6 @@
|
||||
// FILE: SRF05_demo_average.ino
|
||||
// AUTHOR: Rob Tillaart
|
||||
// PURPOSE: demo distance sensor
|
||||
// DATE: 2021-05-17
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
|
||||
|
||||
@ -17,7 +16,11 @@ SRF05 SRF(trigger, echo);
|
||||
void setup()
|
||||
{
|
||||
Serial.begin(115200);
|
||||
Serial.println();
|
||||
Serial.println(__FILE__);
|
||||
Serial.print("SRF05_LIB_VERSION: ");
|
||||
Serial.println(SRF05_LIB_VERSION);
|
||||
Serial.println();
|
||||
|
||||
SRF.setCorrectionFactor(1.035);
|
||||
SRF.setModeAverage(10);
|
||||
@ -31,5 +34,5 @@ void loop()
|
||||
}
|
||||
|
||||
|
||||
// -- END OF FILE --
|
||||
// -- END OF FILE --
|
||||
|
||||
|
||||
@ -2,7 +2,6 @@
|
||||
// FILE: SRF05_demo_median.ino
|
||||
// AUTHOR: Rob Tillaart
|
||||
// PURPOSE: demo distance sensor
|
||||
// DATE: 2021-05-17
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
|
||||
|
||||
@ -17,7 +16,11 @@ SRF05 SRF(trigger, echo);
|
||||
void setup()
|
||||
{
|
||||
Serial.begin(115200);
|
||||
Serial.println();
|
||||
Serial.println(__FILE__);
|
||||
Serial.print("SRF05_LIB_VERSION: ");
|
||||
Serial.println(SRF05_LIB_VERSION);
|
||||
Serial.println();
|
||||
|
||||
SRF.setCorrectionFactor(1.035);
|
||||
SRF.setModeMedian(7);
|
||||
@ -31,5 +34,5 @@ void loop()
|
||||
}
|
||||
|
||||
|
||||
// -- END OF FILE --
|
||||
// -- END OF FILE --
|
||||
|
||||
|
||||
@ -2,7 +2,6 @@
|
||||
// FILE: SRF05_demo_running_average.ino
|
||||
// AUTHOR: Rob Tillaart
|
||||
// PURPOSE: demo distance sensor
|
||||
// DATE: 2021-05-17
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
|
||||
|
||||
@ -21,7 +20,11 @@ SRF05 SRF(trigger, echo);
|
||||
void setup()
|
||||
{
|
||||
Serial.begin(115200);
|
||||
Serial.println();
|
||||
Serial.println(__FILE__);
|
||||
Serial.print("SRF05_LIB_VERSION: ");
|
||||
Serial.println(SRF05_LIB_VERSION);
|
||||
Serial.println();
|
||||
|
||||
SRF.setCorrectionFactor(1.035);
|
||||
SRF.setModeRunningAverage(0.1);
|
||||
@ -35,5 +38,5 @@ void loop()
|
||||
}
|
||||
|
||||
|
||||
// -- END OF FILE --
|
||||
// -- END OF FILE --
|
||||
|
||||
|
||||
@ -5,7 +5,7 @@
|
||||
// DATE: 2021-05-17
|
||||
// URL: https://github.com/RobTillaart/SRF05
|
||||
//
|
||||
// place distance sensor at exactly 1000 millimetre of a reflecting wall
|
||||
// place distance sensor at exactly 1 metre = 1000 millimetre of a reflecting wall
|
||||
// use setCorrectionFactor() to adjust
|
||||
// IDEA - potentiometer 0..1023 maps to 0.900 .. 1.100
|
||||
|
||||
@ -21,25 +21,29 @@ SRF05 SRF(trigger, echo);
|
||||
void setup()
|
||||
{
|
||||
Serial.begin(115200);
|
||||
Serial.println();
|
||||
Serial.println(__FILE__);
|
||||
Serial.print("SRF05_LIB_VERSION: ");
|
||||
Serial.println(SRF05_LIB_VERSION);
|
||||
Serial.println();
|
||||
|
||||
// SRF.setCorrectionFactor(1.035);
|
||||
// SRF.setCorrectionFactor(1.035);
|
||||
}
|
||||
|
||||
|
||||
void loop()
|
||||
{
|
||||
static uint32_t prev = millis();
|
||||
float s = SRF.determineSpeedOfSound(500); // test 500 x 2 meter
|
||||
float s = SRF.determineSpeedOfSound(1.000); // 1000 millimetre
|
||||
uint32_t now = millis();
|
||||
Serial.print(now - prev);
|
||||
Serial.print("\t");
|
||||
Serial.print(500);
|
||||
Serial.print(1.000);
|
||||
Serial.print("\t");
|
||||
Serial.println(s, 1);
|
||||
prev = now;
|
||||
}
|
||||
|
||||
|
||||
// -- END OF FILE --
|
||||
// -- END OF FILE --
|
||||
|
||||
|
||||
@ -30,6 +30,8 @@ getTriggerLength KEYWORD2
|
||||
|
||||
lastTime KEYWORD2
|
||||
|
||||
calculateSpeedOfSound KEYWORD2
|
||||
|
||||
|
||||
# Constants (LITERAL1)
|
||||
SRF05_LIB_VERSION LITERAL1
|
||||
|
||||
@ -15,7 +15,7 @@
|
||||
"type": "git",
|
||||
"url": "https://github.com/RobTillaart/SRF05.git"
|
||||
},
|
||||
"version": "0.1.5",
|
||||
"version": "0.2.0",
|
||||
"license": "MIT",
|
||||
"frameworks": "*",
|
||||
"platforms": "*",
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
name=SRF05
|
||||
version=0.1.5
|
||||
version=0.2.0
|
||||
author=Rob Tillaart <rob.tillaart@gmail.com>
|
||||
maintainer=Rob Tillaart <rob.tillaart@gmail.com>
|
||||
sentence=Arduino library for SRF05 distance sensor
|
||||
|
||||
Loading…
Reference in New Issue
Block a user