Hello!

We have prepared a small tutorial with Raspberry Pi + Ultrasonic

Sensor + Servo Motor. I would try another Raspberry Pi application for

beginners; I looked among the pieces I had at my disposal, and found something

interesting; I searched the internet for information about the parts I have,

how to control them individually, and now I will try to combine them to make an

application for learning purposes.

Components used in this project:

- Raspberry Pi;

- Ultrasonic Sensor HC SR-04;

- Servo Motor SG90;

- PCA9685 PWM Driver.

The first step is to install a library, which will help us use

the PWM driver PCA9685 (Figure 1), useful to control a servomotor, an LED or a

dc motor. Information can be found at this link:

https://learn.adafruit.com/adafruit-16-channel-servo-driver-with-raspberry-pi/using-the-adafruit-library.

Figure 1

We start by opening Terminal Window and writing the command:

sudo pip3 install

adafruit-circuitpython-servokit

We are waiting for the package installation to be completed.

The control of the SG 90 servomotor (Figure 2) is easy, we only

need a few program lines written in Thonny IDE:

from

adafruit_servokit import ServoKit

kit = ServoKit

(channels = 16)

We import and initialize the ServoKit class.

Then, to move the actuator to an angle we want, we add the

command:

kit.servo [0] .angle

= 0

Figure 2

The HC SR-04 ultrasonic sensor (Figure 3) is affordable, easy to

use at 5V.

Figure 3

The electronic scheme according to which the connections are

made is the following:

Figure 4

The servomotor is connected to channel 0 of PCA9685; a supply

voltage of 5V is required for the servomotor and the ultrasonic sensor, and a

3.3V for the logic circuit of the PCA9685; PCA9685 driver, SDA and SCL pins

connect SDA and SCL pins on the Raspberry Pi (physical pins 3 and 5); for the

ultrasonic sensor, the Trig pin -> GPIO23 (physical pin 16) and Echo ->

GPIO24 (physical pin 18).

Practical realization of the project (Figure 5):

Figure 5

The distance is displayed in centimeters, with two decimals, the

program is run in Thonny Python (Figure 6):

Figure 6

Thanks to the PCBWay team for this activity!

We expect as much from you!

Success!