I propose a rangefinder project based on the HC-SR04 ultrasonic sensor and the Arduino board. The sensor readings are displayed on the liquid crystal display, and power is supplied from a 9 volt battery.
It is necessary
- - Arduino Nano;
- - ultrasonic rangefinder HC-SR04;
- - LCD display;
- - body;
- - battery "Krona";
- - 10 kOhm potentiometer;
- - bread board;
- - connecting wires.
Instructions
Step 1
To begin with, you need to choose the right size for the case. The size depends on which Arduino board you are going to use (UNO, Mini, Nano, or another), as well as what size your LCD is. It is possible to use a miniature 3-character LED indicator instead of the LCD. This will be enough to display the distance in centimeters, because the ultrasonic sensor used has a measuring range of 3 to 400 cm.
Step 2
Let's estimate how the parts will be arranged inside the body. Cut out the holes for the ultrasonic sensor, for the display and for the on-off switch.
Step 3
Now let's look at the circuit of our device. Power supply - from battery "Krona" 9 V. Toggle switch S1 - to turn the device on and off. The liquid crystal display (LCD) is connected in a standard way with a 10 kΩ potentiometer to adjust the contrast. LCD and ultrasonic sensor are powered from 5 V.
Step 4
Let's write a sketch for our rangefinder. Everything is simple here. First, we initialize the LCD on pins 12, 11, 10, 9, 8 and 7 using the LiquidCrystal library from the Arduino IDE.
Next, we connect the trigger and echo pins of the rangefinder to pins 6 and 5 of the Arduino board.
Every 50 ms we will request the distance from the detector using the getDistance () function and display it on the LCD.
Step 5
After we have written the sketch to the Arduino memory, we can assemble the device. The layout of the internals that I suggest is shown in the figure. I fixed the display and sensor with hot melt glue. It holds quite firmly, but at the same time makes it possible to remove the connected parts, if necessary. It is advisable to place everything so that you can connect to the USB port of the Arduino and fix the "firmware" if necessary. For example, change the displayed text or correct the coefficients for calculating the distance. It may be necessary to change the contrast of the LCD, so it is also advisable to have a potentiometer adjuster available.
Step 6
A version of the finished device is shown in the photo. It is quite compact and easy to use. Of course, such a device has its own characteristics. Several important usage tips are provided at the end in the helpful tips section.
