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oak:tutorials:ultrasonic [2016/07/29 18:23] brohan |
oak:tutorials:ultrasonic [2017/01/10 00:04] (current) Rover#18 [Components] cross-referencing to tutorial for HC-SR04 |
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| {{http://digistump.com/wiki/_media/oak/tutorials/us-100_ultrasonic_2.png?500}} | {{http://digistump.com/wiki/_media/oak/tutorials/us-100_ultrasonic_2.png?500}} | ||
| - | In this lesson, we will connect an ultrasonic sensor to the Oak. An ultrasonic sensor, using the properties of sound, not only detect an object, but also how far away the object is. The sensor generates a high frequency sound, then listens for an echo received back to the sensor. The time interval from send to receive allows you to calculate the distance. | + | In this lesson, we will connect an ultrasonic sensor to the Oak. An ultrasonic sensor, using the properties of sound, not only detects an object, but also detects how far away the object is. The sensor generates a high frequency sound, then listens for an echo received back to the sensor. The time interval from send to receive allows you to calculate the distance. |
| ===== Components ===== | ===== Components ===== | ||
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| - | **Note:** The HC-SR04 sensor is __**NOT**__ being used in this tutorial as it uses 5v. Instead a US-100 sensor, which operates from 3v - 5v is used. | + | **Note:** The HC-SR04 sensor is __**NOT**__ being used in this tutorial as it uses 5v. Instead a US-100 sensor, which operates from 3v - 5v is used. However, two methods for connecting the more common HC-SR04 range sensor are provided in a separate tutorial, [[https://digistump.com/wiki/oak/tutorials/ultrasonic_2|here]]. |
| Particle.publish will be used to send the sensor data to the cloud. To view the data, you will need your free Particle account. You most likely created one when you first set up your Oak. If you don't have one already get yours here: [[https://build.particle.io/signup]]. | Particle.publish will be used to send the sensor data to the cloud. To view the data, you will need your free Particle account. You most likely created one when you first set up your Oak. If you don't have one already get yours here: [[https://build.particle.io/signup]]. | ||
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| ==== pulseIn ==== | ==== pulseIn ==== | ||
| - | pulseIn()can be thought of as a specific timer. pulseIn() takes at least 2 parameters, and up to 3, which are: pin, HIGH or LOW, and timeout. pulseIn() reads the pulse width value for the designated pin during a signal HIGH or LOW condition (designated by the state parameter). Pulse width value is the length of time the pin’s voltage remains HIGH or LOW. | + | pulseIn() can be thought of as a specific timer. pulseIn() takes at least 2 parameters, and up to 3, which are: pin, HIGH or LOW, and timeout. pulseIn() reads the pulse width value for the designated pin during a signal HIGH or LOW condition (designated by the state parameter). Pulse width value is the length of time the pin’s voltage remains HIGH or LOW. |
| For example, when the state parameter is set to HIGH, the pulseIn() function waits for the pin’s voltage change to HIGH and measures the length of time the pin’s voltage remains HIGH until it changes to LOW. The length of time is measured in millisecond. The maximum pulse width is 71 minutes. If nothing is detected within the specified time-out period, the function abandons the read attempt and returns 0. | For example, when the state parameter is set to HIGH, the pulseIn() function waits for the pin’s voltage change to HIGH and measures the length of time the pin’s voltage remains HIGH until it changes to LOW. The length of time is measured in millisecond. The maximum pulse width is 71 minutes. If nothing is detected within the specified time-out period, the function abandons the read attempt and returns 0. | ||