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In this lecture, you have to use the agency as 04 ultrasonic distance, since the sensor provides an

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easy way to measure the distance between itself and a usually flat, reflective object in front of it,

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like this container that I'm using here as a sample target.

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The principle of operation for this sensor is that you've got two modules.

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One emits an ultrasound which bounces off the object in front of it and goes back into the receiver.

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And the amount of time that it takes for the signal to travel between the emitter and the receiver provides

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information so that the distance can be calculated.

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Now, in this case, I needed to find a easy to use and reliable driver for the census so that I didn't

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have to code the functionality myself.

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And to do that, I was able to go to the market.

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Python listing of such drivers, search for distance since ultrasonic or something like that.

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And it's I was able to find this driver right here, click on it, and it will take you to the GitHub

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repository where you've got some information on how to use it.

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And of course, you've got access to the driver itself, the python drive itself, so you can click

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on the raw button just to get a clear text of the code of the driver.

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Copy that and then create a new page in phony paste the code in and save it on your device using this

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name here, HTC.

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And this call is scheduled for in lowercase because this is the name that I use to import this code

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into my example script.

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So I've already done that, of course.

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So I'm not going to repeat the process here to save a bit of time.

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This is the example script that are prepared.

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As you can see, it's very simple.

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I've got some information on how to connect the sensor to your ESP three to using the regular ground

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and three point three four panes for power.

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And then the echo pin, which is the second from the right, which is this pin right here via a couple

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of jumper wires, goes to Tip-offs 15 right there.

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And then the trigger pin, which is this pin right here, goes to be able to OK, those embedded with

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the connections, nothing fancy.

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I've got information about the driver so you can download the driver and install it or save it on your

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HP 32.

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And as far as the script itself is concerned, I'm importing the necessary modules and I'm creating

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the sensor object as per the instructions from the driver module.

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I'm calling the CSR constructor, passing the trigger and expense.

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And there's also Eneko Timeout is a pretty large number in microseconds.

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I'm using a hardware timer here like I've done in previous lectures, and I'm taking reading every one

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second, one third milliseconds periodically.

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And every time that the timer expires, it will call the interrupted service routine, which is this

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one here.

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I'm simply getting a distance measurement in centimeters and I'm rounding this number to two decimal

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points and printing it out.

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And because I've got just a simple number here, I can also use the pleura, which gives me a nice visual

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representation.

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So actually it really works.

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So I'm going to move the target, make it a bit closer.

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You can see that the.

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Numbers change as well as a plot of that number back a little.

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This just increases.

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You can take more frequent measurements, for example, I've gone down to 250 milliseconds, depending

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on the distance that you want to measure, you need to be mindful of how frequently you can take measurements.

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If you want to take measurements that are, say, beyond 10 or 20 centimeters, then you need to take

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into account the amount of time that is needed for the ultrasound to travel back and forth.

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And it seems that about half a second to a second is a good number for such measurements.

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Right.

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So that's about it with the want system since the.