... | ... | @@ -37,16 +37,16 @@ In theory the actual and the measured distance should be identical. However many |
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### Exercise 2
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identical measurements - Due to blocking call so the system waits
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The setup and process in this exercise is identical to the one in exercise 1. The result however do not change no matter what the sample interval is set to. This is due to the blocking functionality of the sensor which means that whenever a reading is requested, the program locks until the particular reading is done. Therefore the sample interval do not affect the readings from the sensor.
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### Exercise 3
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Battery almost out of power - might affect the measurements
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The process in this exercise was to place the LEGO car with the ultra sonic sesnor mounted close to a wall and then pulling it backwards while reading the distance from the LCD. Unfortunatly it was not possible to measure a distance above ~150cm. This can be caused by multiple factors.
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The delay from sending a ultrasonic sound, until the echo is received is 2*distance/speed of sound.
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For the maximum distance of 2.54m the delay will be 2*2.54m /343.21m/s = 14.8ms.
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Assuming the air temperature is 20 degrees of celcius.
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This puts a physical time limitation on the usage of the sensor.
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For the maximum distance of 2.54m the delay will be 2*2.54m /343.21m/s = 14.8ms assuming the air temperature is 20 degrees of celcius. This puts a physical time limitation on the usage of the sensor. Therefore if the temperature in the room is not exactly 20 degrees celcius this will affect the sensor reading.
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Another important factor is battery level. When the test were carried out the battery level of the LEGO car was minimal which affects the ultra sonic transmission power and thereby also the sensor reading.
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### Exercise 4
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