Small Car Using Arduino Pro Mini and ESP8266

The Small Car can be controlled with infrared and WIFI.

​Components

• Arduino Pro Mini x1
• ESP8266-01S x1
• Motor Drive：L298N x1
• IR Kit: Receiver and Remote Controller
  • Receiver：VS1838B x1
  • Remote Controller: 21 Keys x1
• Ultrasonic Sensor：HC-SR04 x1
• Shift Register：74HC595N x1
• Speed Detection
  • Encoder Wheel x2
  • H206 Optical Interrupter Sensor x2
• Buzzer(active) x1
• LED: 5mm Yellow x2
• Resistor: 220Ω x2, 100K x1
• Capacitance：47μF x1, 0.1μF x1
• 2WD Robotic Car Kit (2 wheels, 2 motors, and a chassis) x1
• Power: 7.4V 800mAh Lithium Battery x1
• 400-Point Breadboard x2
• Connecting Wires and Jumper Wires
• FTD1232-1 mini-USB to TTL converter x1

Arduino Libraries

Arduino UNO

• IRremote
• SoftwareSerial
• ArduinoJson

ESP8266

• ESP8266WiFi
• ESPWebServer
• ArduinoJson

Arduino Sketches

1. SmallCar_Arduino.ino

   • Remote Controller: IR and WIFI
   • Web App：Control Buttons only

2. SmallCar_Arduino_WIFI.ino

   • Remote Controller: WIFI only
   • Web App：Control Buttons, the obstacle distance, the car speed

Layout

400-Point Breadboards

Breadboard 1

• IR Receiver, Ultrasonic Sensor,LEDs,Resistor,Buzzer,74HC595

Breadboard 1	Arduino Pro Mini
+5V	VCC
GND	GND

Breadboard 2

• Arduino Pro Mini，Capacitancs

Breadboard 2	L298N
+5V	+5V
GND	GND

IR Receiver VS1838B

#define IR_RECEIVE_PIN 7

IR Receiver
out	Arduino Pro Mini Pin 7
VCC	Breadboard 1 +5
GND	Breadboard 1 GND

Ultrasonic Sensor：HC-SR04

// Ultrasonic - Arduino
#define TRIG_PIN 8  // Trigger
#define ECHO_PIN 9  // Echo

HC-SR04
VCC	Breadboard 1 +5V
Trigger	Arduino Pro Mini Pin 8
Echo	Arduino Pro Mini Pin 9
GND	Breadboard 1 GND

Yellow LEDS

// Led - 74HC595 
#define LED_LEFT_PIN_SR 6 // +
#define LED_RIGHT_PIN_SR 5 // +

Left LED
+	220Ω ->74HC595 Pin 6
-	Breadboard 1 GND

Right LED
+	220Ω -> 74HC595 Pin 5
-	Breadboard 1 GND

Active Buzzer

#define BUZZER_PIN_SR 0 // 0 is the No. of Shift Register,P15

Active Buzzer
+	74HC595 Pin 15
-	Breadboard 1 GND

Shift Register：74HC595N

#define LATCH_PIN 13
#define CLOCK_PIN 4
#define DATA_PIN 12

74HC595N
QB Pin 1	L298N IN4
QC Pin 2	L298N IN3
QD Pin 3	L298N IN2
QE Pin 4	L298N IN1
QF Pin 5	Right LED
QG Pin 6	Left LED
GND Pin 8	Breadboerd 1 GND
SRCLR Pin10	Breadboerd 1 GND
SRCLK(Shift Register Clock) Clock Pin 11	Arduino Pin 4
RCLK(Register Clock) Latch Pin 12	Arduino Pro Mini Pin 13
SER(Serial Input) Data Pin 14	Arduino Pro Mini Pin 12
QA Pin 15	Active Buzzer
VCC Pin 16	Breadboerd 1 +5V

To configure 74HC595 to have low pin outputs at power on

74HC595N
QE Pin 13	47μF -> Breadboard 1 +5
	100K -> Breadboard 1 GND
VCC Pin 16(Breadboard 1 +5V)	0.1μF -> Breadboard 2 GND

H206 Optical Interrupter Sensor

H206
Right H206 OUT	Arduino Pro Mini Pin 3
Left H206 OUT	Arduino Pro Mini Pin 2
VCC	Breadboard 1 +5V
GND	Breadboard 1 GND

L298N

// L298N - 74HC595
#define MOTOR_LEFT_FORWARD_PIN_SR 4  // IN1 OUT1 -
#define MOTOR_LEFT_BACK_PIN_SR 3     // IN2 OUT2 +
#define MOTOR_RIGHT_FORWARD_PIN_SR 1 // IN4 OUT4 +
#define MOTOR_RIGHT_BACK_PIN_SR 2    // IN3 OUT3 -

// L298N - Arduino
#define LEFT_PWM_PIN 6  // ENB
#define RIGHT_PWM_PIN 5  // ENA

L298N
IN4	74HC595N Pin1
IN3	74HC595N Pin2
IN2	74HC595N Pin3
IN1	74HC595N Pin4
OUT4	Left Motor +
OUT3	Left Motor -
OUT2	Right Motor +
OUT1	Right Motor -
ENB	Arduino Pro Mini Pin 6
ENA	Arduino Pro Mini Pin 5
VCC	Lithium Battery +
GND	Lithium Battery - and Breadboard 2 GND
+5V	Breadboard 2 +5V

Arduino Pro Mini

Arduino Pro Mini
Pin 13	74HC595 LATCH_PIN 12
Pin 12	74HC595 DATA_PIN 14
Pin 11	ESP8266 RX
Pin 10	ESP8266 TX
VCC	Breadboard 1 +5v
Vin	Breadboard 2 +5v
Pin 9	HC-SR04 Echo
Pin 8	HC-SR04 Trigger
Pin 7	IR Receiver out
Pin 6	L298N ENB
Pin 5	L298N ENA
Pin 4	74HC595 CLOCK_PIN 11
Pin 3	Right H206, intercept 1
Pin 2	Left H206, intercept 0
GND	Breadboard 1 GND

ESP8266-01S

// Softserial: ESP8266 - Arduino 
#define SS_RX_PIN 10
#define SS_TX_PIN 11

ESP8266
VCC3.3	Breadboard 1 +3.3V
RX	Arduino Pro Mini Pin 11
TX	Arduino Pro Mini Pin 10
EN(CH_PD)	Breadboard 1 +5V
GND	Breadboard 1 GND

FTD1232-1 mini-USB to TTL converter

Uploading the Sketch to the Arduino Pro Mini

FTD1232-1	Arduino Pro Mini
GND	GND
VCC	VCC
TXD	RXD
RXD	TXD
DTR	GRN(DTR)

Uploading the Sketch to the ESP8266-01

FTD1232-1	ESP8266
RXD	TX
TXD	RX
VCC	CH_PD
GND	IO0(GPIO_0)(pull-down: USRT Download)
VCC	VCC
GND	GND