Published November 30, 2023 © CC BY

Smart delivery robot

Smart environmentally friendly Raspberry Pi-powered robot used to deliver small packages

AdvancedWork in progress2 days1,606

Things used in this project

Hardware components

Raspberry Pi 4 Model B

I used 4GB ram that is enough

Arduino Nano Every

Ultrasonic Sensor - HC-SR04 (Generic)

HMC5883L

MPU6050

HX711

weight sensor 5 kg

5 mm LED: Yellow

5 mm LED: Red

Adafruit LED 5mm white

3 mm LED: Green

Adafruit 3mm LED blue

not sixpacks, but six LEDS

Through Hole Resistor, 200 ohm

Resistor 330 ohm

cd4017

18650 Battery

18650 holder x2

Raspberry Pi Camera Module

USB webcam

Czech web, because I didn't find it on us web. You can use any webcam that fits

Solar panel

TaydaElectronics DC POWER JACK 2.1MM BARREL-TYPE PCB MOUNT

Step up module

switch

l298N

25GA-370 6V 620RPM

5v 30x30x8 fan

6-24 v to USB

BMS module 2s 20A

5v one channel relay

electromagnetic lock 12v

Adafruit 3x4 keypad

SparkFun IR line sensor

Software apps and online services

Autodesk Fusion

Prusaslicer

Raspberry Pi Raspbian

thonny

OpenCV

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Hot Air Station, Industrial

Torque, Control Screwdriver

Drill / Driver, Cordless

knife with snap off blades

3D Printer (generic)

I use Prusa MINI+

dremel tool

Tape, Double Sided

shrink insulation tubes

wires

Story

SMART DELIVERY ROBOT

I made a smart delivery robot as an OpenCV AI Competition 2023 entry. You can get brief info in video or in text below.

Video of my project

This project is a six-wheeled robotic vehicle. It can transport small packages to many places like hospitals, restaurants, offices, or warehouses. When packages are transported, the top cover is locked. After reaching the destination, the robot waits to enter the pin code on the keypad on the lid or you can show it a special QR code for receiving the package, if it's verified successfully, the top cover unlocks. The vehicle rides on green guiding lines that must be placed at places, where robots can go through, more info is in a chapter called Using Robot.

BUILD OF THE ROBOT

3D printing

Firstly, you must 3D print all mechanical parts. You can find them in the CAD files list and download them, but you must rearrange the. I 3D printed them with PLA with 15% infill, only tires were printed from FLEX, and also 15% infill.

Base assembly

The next step will cover the assembly of the base (plate with Raspberry Pi 4B, motors, and more). Take a 3d printed piece BasePlate, put Raspberry Pi 4B on four sticks on the print, and cover them with four 3d printed parts RPI_EndCap. Then, you need to stick two L298N motor controllers with double-sided tape to frames for them (you must orient them so that the power connectors are facing each other). Then, take a 3d printed piece CPU_Fan_Holder and glue it to the hole used for the fan (long thin rectangle) with instant glue. Now put the 30x30x8 mm fan and put it inside (cables must go through the side hole of the part. Cover it with 3d print FanFrame. After that, connect L298N modules as in the Fritzing diagram below. Connect the CPU fan's red wire to Raspberry Pi's 5v pin, and the black wire into the GND pin.

base part connections

Motors and bottom piece assembly

After building the base, you must build the bottom part of the vehicle. Put all six motors in a 3d print called Motor_Case. Then, take Bottom_Plate and glue it with instant glue to the base (orientation doesn't matter. Now put all motors with covers into half-cylinders with the circular side. Don't forget to push cables through small holes in the bottom part, this may be tricky, but it's needed. Then glue Motor_EndCap on all motors' outside ends. Now, put tires on wheels. After that, install wheels on the motors' shafts. Now you have the bottom part installed, let's move -on to installing the medium part with lights and power management. Through small holes, you must install line following sensors. Connect left sensors to GPIO 6, right to GPIO 5.

motor connections

Lights and power management assembly

Now take a 3d print called LightsPowerMain and glue its bottom sticks to the top of previously assembled parts - three big rectangles (battery holders are above Raspberry Pi 4B and it's front of the robot). Solder wires to battery holders as in the diagram below, Then put them into the previously mentioned three rectangles. Now take a both-sided tape and stick a 5v relay, battery protection module, two step-up modules, one 6-24v to USB step-down module, and an HX711 AD converter. Glue the DC jack connector in the small hole in the side so that it is accessible. Now, solder the first part of the power management circuit as in the Fritzing diagram for batteries. Next, put batteries into holders. After that, put a second 30x30x8 mm fan in the front hole, wires must go inside the vehicle. Cover it with antoher FanFrame 3d printed part. Now assemble four LED sets (five white (front) or red (back) LEDS and one yellow LED on the ends) and connect them to Raspberry Pi as in the Fritzing diagram. After that, tape the front camera, lens must be visible, if it doesn't fit, you must redesign the file for your webcam. Plug that webcam into the USB port in Raspberry Pi. Next, install two HC-SR 04 sensors from the inside. Don't connect them now. Then, connect USB A to USB C cable to step down the module and the second end of the cable to the power socket on Raspberry Pi. Finally, again connect the red cable of the fan to Raspberry Pi's 5 V pin and the black wire to the GND pin.

First part of power management - if you don't step down with usb output, like in diagram, you must set it with trimmer to 5v, else your RPi will be damaged

Diagram for connecting lights.

Sensor plate assembly

Take a 3d print called SensorPlate. Glue it on the lights and power plate (orientation - small hole is facing back. Stick RPi camera v 1.3 to that hole (lens is visible, connect the CSI cable to RPi. Put Arduino nano every, MPU 6050 gyroscope accelerometer and HMC5883L magnetometer (compass) into this print. Connect Two HC-SR04 sensors from the previous chapter as in the first Fritzing diagram below. Then connect MPU 6050, and HMC5883L as in Fritzing diagrams two and three. Then, solder the load cell to HX711 and connect the HX711 module to Arduino nano every as in the fourth Fritzing diagram. Before you put the load cell into the 3d print, you must screw two M4x16 screws on one side of the load cell with screw heads down, and on the other side do it with screw heads up. Stick on the bottom with screw heads. Glue top screw heads to piece called Loadcell_Top. Now return to batteries and stick a 10K NTC thermistor to the top of one battery. Connect it to Arduino via a 10K resistor like in the fifth diagram (don't connect the LDR that will be connected at the end of the build. Also, connect the relay to Nano every's pin D6 like in the sixth diagram. Did you spot two unused holes in the print? They are for optional installation of NEO 6M GPS module and antenna, that aren't used in the code (for future upgrades), if you want to place it, wire it like in the last Fritzing diagram. Lastly, connect the micro usb cable from arduino nano every to Raspberry Pi 4B and cover HMC5883L with CompassCover, MPU6050 with GyroCover and Arduino Nano Every wirh NanoEveryCover

HC-SR04 wiring to Nano every (Nano used, because there isn't nano every in my fritzing

MPU6050 connection

HMC5883L connection

load cell assembly

connect thermistor like in this diagram

relay connection

GPS installation (optional)

The bottom part of the package area assembly

This part of the assembly will be very easy. Just take a 3d printed part called BottomPackagePlate and glue it to the previously assembled part (orientation - hole for load cell must be above the load cell).

Package box assembly

The next easy part is assembly of the package box. You will only take the 3d print called PackageBox and put it on the assembly (orientation - big cable organization holes on two pieces are fitting. Lastly, you will glue them together.

The top assembly

After the rest parts of the build, there will be a very hard last part of the robot's build - the top of the robotic vehicle.Take 3D print called Top, put there print called lid, pull the LidRod through and attach LidCaps to ends of the rod (like in image below). Let's continue with the solar panel. Connect it to a switch to turn the solar panel on and off like in the Fritzing diagram below, then connect it to one of step up modules and set the step-up module to 8.4v (shine a light on the solar panel, connect output pins on the multimeter, spin the trimmer on step-up module and reach 8.4v). After that, connect the 12 V electromagnetic lock to the NO and COMs pin of the relay and the other step-up modules like in the second Fritzing diagram. Glue the lock into rectangle with text "lock" on the bottom of print, lock latch must be outside the moving part, you need to press the latch while installing. In the small hole on the top install LDR as in Fritzing diagram for thermistor. Now install 3 green 3 mm LEDs with 200-ohm resistors to a compartment with three small holes and connect them to Arduino as the third Fritzing diagram. Now connect 6 3 mm LEDs with 200-ohm resistors into CD4017 and put LEDs into a small compartment with six small holes. After that, you need to connect CD4017 to Arduino like in the fourth Fritzing diagram. Then connect 12 button keypad as in fifth Fritzing diagram. below. Pull all cables through a big thin hole at the back. Next, glue the assembled top to the robot (rounded square is in front of the robot). Finally in the rounded square in the front part you can stick a NFC tag and put 3d print NFCSign on it or don't use NFC and use NoNFCSign print. YOU DID IT!

solar panel installation

lock connection

lock status indicator

CD4017 and blue LEDs installation.

keypad installation

Montage of roof

USING THE ROBOT

If you want to use the robot, you must copy the Python script to Raspberry Pi4 and make it run automatically this way.

1) Firstly, open the terminal and run the crontab script for the user that you want to execute the python script on login

$ crontab -e

2) If you're using crontab the first time, you may need to choose text editor in the terminal, if it's possible, choose nano.

3) Download the main program from my Hackster.io project

4) Run these two commands (you may need to enter your password)

cd /home
sudo mkdir robot

5) Find your file - if you have a file downloaded into the default folder, run this code, but you need to change the username, or if you didn't download it to the default folder, write cd / followed by your file location (folder).

cd /home/your_rpi_username/Downloads

6) Move the file to the correct directory

sudo mv robotmainscript.py /home/robot

7) Add this code to the file. It makes the script run on the boot of Raspberry Pi.

@reboot /home/robot/robotmainscript.py

8) Test it

sudo reboot

Use black lines instead of color lines in videos. You can get a lot info from code (only a draft for creating code for your own purpose, may not work with some versions of Raspbian). QR codes can be created with https://www.the-qrcode-generator.com/. I worked on this project for long time, thanks for making it. Vit Skvara

Schematics

Code

int incomingByte = 0;
int thermistorPin = A0;
int thermistorVal = 0;
int ldrPin = A1;
int ldrVal = 0;
int trigPin = 2;
int echoPin = 3;
int trigPin2 = 4;
int echoPin2 = 5;
int relay = 6;
int green = 11;
int count = 12;
int resetcounter = 13;
long response1, range1, response2, range2;
void setup() {
  Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
  pinMode(relay, OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(count, OUTPUT);
  pinMode(resetcounter, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  digitalWrite(green, HIGH);
  delay(1000);
  digitalWrite(green, LOW);
}

void loop() {

  if (Serial.available() > 0) {
  incomingByte = Serial.read(); // read the incoming byte:
  Serial.println(incomingByte);
  if(incomingByte == 82){ //send char R to turn relay off (unlock the robot)
    Serial.println("Relay ON");
    digitalWrite(relay, HIGH);
    digitalWrite(green, HIGH);
    }
  else if(incomingByte == 114){ //send char r to turn relay off (lock the robot)
    Serial.println("Relay OFF");
    digitalWrite(relay, LOW);
    digitalWrite(green, LOW);
    }
  else if(incomingByte == 84) //count +1 to written chars
  {
  Serial.println("Keypad button pressed");
  digitalWrite(count, HIGH);
  delay(100);
  digitalWrite(count, LOW);
  }
  else if(incomingByte == 116)//reset counter
  {
    digitalWrite(count, LOW);
    digitalWrite(resetcounter, HIGH);
    delay(100);
    digitalWrite(resetcounter, LOW);
    Serial.println("Counter IC resetted");
    
  }
  }
   thermistorVal = analogRead(thermistorPin);
   if (thermistorVal < 350)
   {
    Serial.println("BatteriesAreGettingHot"); //hot battery warning
   }
   ldrVal = analogRead(ldrPin); //LED intensity adjustment
   if(ldrVal > 800)
   {
      Serial.println("Lights3");
   }
   else if(ldrVal > 600)
   {
      Serial.println("Lights2");
   }
   else
   {
      Serial.println("Ligths1");
   }
  digitalWrite(trigPin, LOW); //reading data from front sensor
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(trigPin, LOW);
  response1 = pulseIn(echoPin, HIGH);
  range1 = response1 / 58.31;
  Serial.print("Range1");
  Serial.println(range1);
 
  digitalWrite(trigPin2, LOW); //reading data from back sensor
  delayMicroseconds(2);
  digitalWrite(trigPin2, HIGH);
  delayMicroseconds(5);
  digitalWrite(trigPin2, LOW);
  response2 = pulseIn(echoPin2, HIGH);
  range2 = response2 / 58.31;
  Serial.print("Range2");
  Serial.println(range2);
  delay(500); //delay for controller pause
}

import cv2
import serial
import RPi.GPIO as gpio
import numpy as np
from gpiozero import Robot, LineSensor
from signal import pause
from time import sleep
correctqrpin = "123-456" #write your own correct qr code for recieving (change after delivery), must be string - 3 numbers, semicolon and 3 more numbers
cap = cv2.VideoCapture(0)
qcd = cv2.QRCodeDetector()
ser = serial.Serial('dev/tty/your-port name', 9600)
ser.bytesize = 8
ser.parity  ='N'
ser.stopbits = 1
gpio.setwarnings(False)
gpio.setmode(GPIO.BCM)
robot = Robot(left=(14, 15), right=(4, 18))#you must change pin numbers like your main L298N
left_sensor = LineSensor(4)
right_sensor = LineSensor(5)
writtenqrpin == ""
firstrun = True
while True:
    ret, frame = cap.read()
    qretval, decoded_info, points. straight_qrcode = qcd.detectAndDecodeMulti(frame)
    data = ser.readline().decode('utf-8').strip()
    if firstrun == True:
        #show QR code with number of unloading spot to go
        if decoded_info != "":
            place_to_go = decoded_info
    if data == "BatteriesAreGettingHot":
        print("Batteries extremely overheated, quitting")
        break
    elif data.startswith("Range1"):
        substring1 == "Range1"
        range1 = data.replace(substring1, "")
    elif data.startswith("Range2"):
        substring2 == "Range2"
        range2 = data.replace(substring2, "")
    if delivered == True:
        if qretval == True:
            writtenqrpin = decoded_info
        if writtenqrpin == correctqrpin:
            print("Correct QR")
            for indicator in range(6):
                ser.write(b'R')
                sleep(0.5)
            sleep(5)
            ser.write(b'r')
            delivered = False
        elif writtenqrpin == "":
            print("No QR")
        else:
            print("QR is incorrect")
            ser.write(b'r')
            ser.write(b't')
    else:
        left_detect  = int(left_sensor.value)
        right_detect = int(right_sensor.value)
        if left_detect == 0 and right_detect == 0:
            left_mot = 1
            right_mot = 1
        if left_detect == 0 and right_detect == 1:
            left_mot = -1
        if left_detect == 1 and right_detect == 0:
            right_mot = -1
        yield (right_mot * speed, left_mot * speed)
        robot.source = motor_speed()
        if decoded_info != "":
            if decoded_info.startswith("place-"):
                placesubstring="place-"
                placeinfo = decoded_info.replace(placesubstring, "")
                if placeinfo.trim() == settedplace:
                    delivered = True
            elif decoded_info.startswith("left-"):
                left_part, right_part = input_string.split(';')
                left_numbers = [int(num) for num in left_part.split('-')[1].split(',')]
                right_numbers = [int(num) for num in right_part.split('-')[1].split(',')]
                place_to_go_int = int(place_to_go)
                if place_to_go_int in left_numbers:
                    #go left
                    robot.forward(0.5)
                    sleep(1)
                    robot.left(0.5)
                    sleep(0.5) #you must adjust timing with experiments of turning time of your robot
                    robot.forward(0.5)
                    sleep(1)
                elif place_to_go_int in right_numbers:
                    #go right
                    robot.forward(0.5)
                    sleep(1)
                    robot.right(0.5)
                    sleep(0.5) #you must adjust timing with experiments of turning time of your robot
                    robot.forward(0.5)
                    sleep(1)
robot.stop()
robot.source = None
robot.close()
left_sensor.close()
cap.close()
right_sensor.close()

Credits

Vit Skvara

1 project • 1 follower

I'm young student that is interested in technology.

Smart delivery robot

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

SMART DELIVERY ROBOT

BUILD OF THE ROBOT

USING THE ROBOT

Custom parts and enclosures

Robot F3D

Robot STL

Robot 3MF

Schematics

Power

HCSR04

Base

MPU6050

Load cell

Keypad

Analog sensors

Lights

Leypad lights

GPS

Motors

Power 2

Indicator

Relay

Lock

HMC5883L

Code

Arduino code

CodeforRPi

Credits

Vit Skvara

Comments

Embed the widget on your own site

Smart delivery robot

Smart delivery robot

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

SMART DELIVERY ROBOT

BUILD OF THE ROBOT

USING THE ROBOT

Custom parts and enclosures

Robot F3D

Robot STL

Robot 3MF

Schematics

Power

HCSR04

Base

MPU6050

Load cell

Keypad

Analog sensors

Lights

Leypad lights

GPS

Motors

Power 2

Indicator

Relay

Lock

HMC5883L

Code

Arduino code

CodeforRPi

Credits

Vit Skvara

Comments

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