robodatech.Complete component list
| Component | Role | Student explanation |
|---|---|---|
| Arduino Nano | Brain/controller | Reads sensors and sends commands to driver, servo, Bluetooth, and RF. |
| 2 x BO motor | Movement | Left and right wheels for differential steering. |
| L293D motor driver | Motor power control | Lets Arduino control motor direction and speed safely. |
| HC-05 Bluetooth | Phone control | Receives F/B/L/R/S commands from a phone app. |
| 2 x 3.7 V Li-ion | Energy | Series pack gives about 7.4 V for motors; use protected cells. |
| Micro servo | Sensor movement | Turns the ultrasonic sensor left/center/right. |
| Ultrasonic sensor | Distance sensing | Measures front distance for obstacle avoiding. |
| 2 x IR sensors | Line sensing | Detects dark/light path for line following. |
| RF module | Wireless experiment | Compares another radio control method with Bluetooth. |
| Small breadboard | Prototyping | Temporary wiring and distribution. |
Support items also needed: robot chassis, two wheels, castor wheel/skid, jumper wires, battery holder, switch, 5 V regulator, USB cable, and safe Li-ion charging method.
Arduino Nano pin wiring schematic
Connection reference for this build
- Components Arduino Nano pin wiring schematic
- Straight lines show electrical nets. Check the printed labels on each real module before connecting power.
- +5V logic rail
- 7.4V motor rail from 2 x 3.7V Li-ion through switch
- Common GND rail
- Arduino Nano
- D2 HC-05 TX
- D3 HC-05 RX divider
- D4 Ultrasonic TRIG
- D5 L293D ENA PWM
- D6 L293D ENB PWM
- D7 Ultrasonic ECHO
- D8 L293D IN1
- D9 L293D IN2
- D10 L293D IN3
- D11 L293D IN4
- D12 Servo SIG
- A0 Left IR OUT
- A1 Right IR OUT
- A2-A5 RF F/B/L/R
- L293D
- Pin 1 EN1,2 = D5
- Pin 2 IN1 = D8
- Pin 7 IN2 = D9
- Pin 9 EN3,4 = D6
- Pin 10 IN3 = D10
- Pin 15 IN4 = D11
- Pin 8 VCC2 = 7.4V motor
- Pin 16 VCC1 = +5V logic
- Pins 4,5,12,13 = GND
- Left BO
- Right BO
- HC-05
- VCC 5V, GND
- TXD D2, RXD D3
- HC-SR04
- TRIG D4
- ECHO D7
- Servo
- SIG D12, 5V, GND
- IR Pair
- Left A0, Right A1
- RF Module
- F/B/L/R to A2-A5
- Breadboard
- Distribute 5V/GND
- Blue = Arduino signal, red = power, gray = ground, orange line = motor battery rail. Connect battery only after checking every net.
Full circuit schematic
Teacher note: Use this schematic to explain signals, power, and ground before students start physical wiring on the breadboard.
Connection reference for this build
- Components circuit schematic
- Mode-specific schematic: only the modules needed for this build are shown.
- +5V regulated logic rail
- 7.4V motor rail from 2 x 3.7V Li-ion through switch
- Common GND rail
- Arduino Nano
- D2 Bluetooth RX from HC-05 TX
- D3 Bluetooth TX to HC-05 RX divider
- D4 Ultrasonic TRIG
- D7 Ultrasonic ECHO
- D12 Servo signal
- D5 L293D ENA PWM
- D6 L293D ENB PWM
- D8-D11 L293D inputs
- A0 Left IR
- A1 Right IR
- A2-A5 RF decoded inputs
- L293D
- Pin 1 EN1,2 from D5
- Pin 2 IN1 from D8
- Pin 7 IN2 from D9
- Pin 9 EN3,4 from D6
- Pin 10 IN3 from D10
- Pin 15 IN4 from D11
- Pin 8 VCC2 from 7.4V
- Pin 16 VCC1 from +5V
- Left
- Right
- HC-05
- VCC to +5V, GND to GND
- TXD to Nano D2
- RXD from Nano D3 divider
- HC-SR04
- TRIG to Nano D4
- ECHO to Nano D7
- Servo
- Signal to Nano D12
- IR Pair
- Left OUT to Nano A0
- Right OUT to Nano A1
- RF Module
- F/B/L/R to Nano A2-A5
- Use matched TX/RX pair
- Breadboard
- Distribute +5V and GND rails
- Blue = Arduino signal, red = power, gray = ground. Arduino GND, L293D GND, battery negative, and module GND must join.
Power rule
Use the Li-ion pack for motor power through L293D VCC2, and regulated 5V for Arduino Nano logic and modules.
Ground rule
All grounds must be common, otherwise the Arduino signal has no reliable reference.
Pin rule
The Arduino programs on this page match this pin plan: D5/D6 PWM, D8-D11 motor direction, D2-D3 Bluetooth, D4/D7 ultrasonic, D12 servo, A0-A5 sensors/RF.