Published April 16, 2019 © LGPL

Body Scanner Using HC-SR04 and ESP8266

Show the insides of a body scan based on distance measurement.

IntermediateFull instructions provided5,248

Things used in this project

Hardware components

Ultrasonic Sensor - HC-SR04 (Generic)

NodeMCU ESP8266 Breakout Board

Story

I made this as an education project to show people what their body looks like on the inside. It works quite simply. The HC-SR04 is used to measure height and this measurement is sent to the computer and is used to display the image of the body. The body images are taken from the VisibleHuman Project https://en.wikipedia.org/wiki/Visible_Human_Project find one you like and convert the movie file to a collection of stills in 8 bit PNG format. I used ffmpeg to do this but there are many other ways to export the still images from a movie but make sure that you export 8 bit PNG into a folder called images. You will need to reverse number the images because you want the lowest distance to show image around the feet not the head. I found this worked for me in Ubuntu run it from CLI in the folder your put all the PNGs in.

Script to reverse number the images

     
for i in {1..50}; do    
    mv "$i.png" "renamed/$(( 50 - $i + 1 )).png"
done

You will need a copy of the Arduino IDE with the Ultrasonic and pubsubclient libraries installed. Make sure you install the ESP8226 platforms as well so that you can talk to the Wemos D1 installation for the ESP8226 can befound here https://github.com/esp8266/Arduino. You could use any ESP8226 for this project just make sure your pins map to the ones you use in the Arduino sketch.

Connect the Wemosdevice to the HC_SR04 and check it works with the Ultrasonic library to work the HC-SR04 https://github.com/ErickSimoes/Ultrasonic.There are other libraries to do this but I found this to be the simplest.

Here is the pin layout for the Wemos D1 I used.

Pin layout for Wemos D1

I originally used serial communication to send the data to the computer but didn’t like the cable connection and went for wireless as this meant I could move a lot further away from the computer. To use WIFI we use anESP8226 and install the pubsubclient libraryhttps://github.com/knolleary/pubsubclientinto the Arduino IDE

Upload this sketch with your own details filled in

Arduino sketch to sample the distance measured and send it via MQTT.

Install MQTT on thecomputer. https://mosquitto.org/download/

When the Wemos is publishing the distance measured you can use this command to see the measurement on your computer

“mosquitto_sub-h Your_IP-p 1883 -t distance -u YourMQTT_username -P Your_MQTT_password”

We are going to use Pygame to display the PNG imageshttps://www.pygame.org/wiki/GettingStarted

If you want you can create a virtual environment for the other modules used in the python program below.

Change the MQTT username and password you set up when installing MQTT.Save the program above the folder with all your images and run the program. When you move the HC-SR04 up and down relative to the floor the image shown on the computer will show the appropriate body cross section for that height. I had 147 images so my scanner works well for someone 147cm tall.

Code

#include <ESP8266WiFi.h>
#include <Ultrasonic.h>
#include <PubSubClient.h>


// Update these with values suitable for your network.
const char* ssid = "Your SSID"; //Replace with your SSID
const char* password = "Your WIFI password"; //Replace with your WIFI password
const char* mqtt_server = "The IP of your computer"; //Replace with the I.P of the computer
const char* mqtt_username = "MQTT username"; //Replace with the username you used in the setup of MQTT on your computer
const char* mqtt_password = "MQTT password";//Replace with the MQTT password you used when you set up MQTT on your computer
const char* clientID = "espClient";
WiFiClient wifiClient;
PubSubClient client(mqtt_server, 1883, wifiClient);
long lastMsg = 100;
// defines variables
long duration;
int distance;
// Defines pins numbers  for Sonar HC-SR04)
Ultrasonic ultrasonic(16, 5); // (Trig, Echoe)

void setup_wifi() {
  delay(10);
  // We start by connecting to a WiFi network
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) 
  {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  // Connect to MQTT Broker
  // client.connect returns a boolean value to let us know if the connection was successful.
  // If the connection is failing, make sure you are using the correct MQTT Username and Password (Setup Earlier in the Instructable)
  if (client.connect(clientID, mqtt_username, mqtt_password)) {
    Serial.println("Connected to MQTT Broker!");
  }
  else {
    Serial.println("Connection to MQTT Broker failed...");
  }
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect("arduinoClient_distance_sensor")) {
      Serial.println("connected");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}
 
void setup()
{
  Serial.begin(115200);
  setup_wifi(); 
  client.setServer(mqtt_server, 1883);  
}

void loop()
{
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
  //Read the distane and publish it to the computer
  long now = millis();
  if (now - lastMsg > 100) {
    lastMsg = now;
    distance = ultrasonic.read(CM);
    client.publish("distance", String(distance).c_str());
    Serial.print("Distance: ");
    Serial.println(distance);
    
  }
}

###demo code provided by Steve Cope at www.steves-internet-guide.com
##email steve@steves-internet-guide.com
###Free to use for any purpose
"""
Passwords demo code
"""

import paho.mqtt.client as mqtt  #import the client1
#import Pygame and system modules
import pygame, sys
#important all  modules
from pygame.locals import *
from os import listdir
from os.path import isfile, join
import glob
import time
import re
# initialize this Pygame.
pygame.init()
#img2 = pygame.image.load("images/out2.jpg")

#Create and set The display area size
screen = pygame.display.set_mode((640, 480))

#create a variable with the colour black.
width = 260
BLACK = (0, 0, 0)
time.sleep(1) #allow sonar to get going
print ("Start")

#set Pygames background colour to black
screen.fill(BLACK)

#filenames = [img for img in glob.glob("images/*.jpg")] #Load the filenames into a list use for .jpg
filenames = [img for img in glob.glob("images/*.jpg")] #Load the filenames into a list use for .png
filenames.sort(key=lambda f: int(''.join(filter(str.isdigit, f)))) #Sort the file list numerically
print (len(filenames))
#while True:
QOS1=1
QOS2=1
CLEAN_SESSION=True
broker="192.168.1.12"

def on_disconnect(client, userdata, flags, rc=0):
    m="DisConnected flags"+"result code "+str(rc)
    print(m)

def on_connect(client, userdata, flags, rc):
    print("distance ",str(flags),"result code ",str(rc))

def on_message(client, userdata, message):
	print("Distance is =",str(message.payload.decode("utf-8")))

	print (str(message.payload.decode("utf-8")))
	if int(str(message.payload.decode("utf-8"))) <= 147: #Only interested in 144 images
		required_image = int(str(message.payload.decode("utf-8")))
		image_wanted = required_image 
		print ("Image number is :", image_wanted)
		img2= pygame.image.load(filenames[image_wanted])
		screen.blit(img2,(130,60))
		pygame.display.flip()
		#update the display
		pygame.display.update()
		time.sleep(0.01)
		
	else:
		print ("Flipping heck")
		blank= "1.jpg"
		screen.blit(blank,(90,60))
		pygame.display.flip()
		#update the display
		pygame.display.update()
	client.disconnect

print("creating client 1 with clean session set to",CLEAN_SESSION)
client1 = mqtt.Client("Python1",clean_session=CLEAN_SESSION)    #create new instance
## edit code for passwords
print("setting  password")
client1.username_pw_set(username="Your_MQTT_username",password="Your_MQTT_password")
##
client1.on_message=on_message        #attach function to callback
client1.on_connect=on_connect
print("connecting to ",broker)
client1.connect(broker)
client1.subscribe("distance")#subscribe
client1.loop_forever()
time.sleep(1)

client1.disconnect()

client1.loop_stop()

Body Scanner Using HC-SR04 and ESP8266

Things used in this project

Hardware components

Story

Schematics

Ultrasonic wiring

Code

Sonar sensor and MQTT

Display images with distance data sent via MQTT

Credits

simonhyde88

Comments

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Body Scanner Using HC-SR04 and ESP8266

Body Scanner Using HC-SR04 and ESP8266

Things used in this project

Hardware components

Story

Schematics

Ultrasonic wiring

Code

Sonar sensor and MQTT

Display images with distance data sent via MQTT

Credits

simonhyde88

Comments

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