Summary of "fire fighting robot Advance Version | Autonomous + Phone Control | Code & Circuit | Full explanation"

Project overview

Presenter: Shahid — electronics engineer who demonstrates a step-by-step build of an improved fire-fighting robot.
Two operation modes:
- Manual: phone control (BT Controller app) via an HC-05 Bluetooth module. From the phone you can control movement, the servo-mounted nozzle, and the water pump.
- Autonomous: the robot scans for flames using an IR flame-sensor array, drives toward the flame, and activates the pump/nozzle to extinguish it.

Key hardware components (bill of materials)

Arduino (referred to as “Dino”); analog pins A0–A5 used for sensors
IR flame sensor array (analog outputs to Arduino A0–A5)
HC-05 Bluetooth module (phone control)
L298N motor driver (12 V input); onboard 5 V regulator used to power Arduino/sensors
4 DC geared motors (mounted to chassis; paired/parallel-wired)
12 V LiPo battery and power on/off switch
Water pump (switched via relay module or MOSFET)
One-channel relay module (IN, VCC, GND) — optional MOSFET alternative
Servo motor (rotates sprinkler/nozzle)
Chassis, wheels, mounting hardware, water tank/reservoir and nozzle
General-purpose PCB, wiring, glue/adhesive

Wiring & electrical design notes

Power:
- L298N 12 V input powers the motors.
- Use the L298N’s onboard regulator (5 V output) to supply the Arduino and sensors only if it can reliably supply Arduino + sensors; otherwise use a separate 5 V supply.
- A common ground between battery, L298N, Arduino, relay, and sensors is required.
Motor driver connections:
- Motor inputs (IN1–IN4) connect to Arduino digital pins (ensure consistent mapping in the code; subtitles mentioned pins 4–7 / A2–A4 — verify).
- Two enable pins should be connected to Arduino PWM pins to control motor speed.
- Motors are paired (two motors per driver channel) and paralleled. Important: confirm both motors in a pair spin the same direction before paralleling, otherwise the paired motors will fight each other.
Pump switching:
- Relay module: VCC and GND to 5 V and ground; IN to a digital pin (example used pin 8).
- Alternatively use a suitable MOSFET to switch the pump.
Bluetooth:
- HC-05 connected to Arduino serial (for BT Controller phone commands).
Sensors:
- Each IR sensor analog output wired to a separate Arduino analog input (A0–A5) for directional flame detection and calibration.

Mechanical assembly

Chassis: four wheels mounted at the corners; motors secured to chassis plate.
Water system: pump mounted inside a box or tank; include fill port and drain.
Nozzle: servo-mounted sprinkler/nozzle on top to aim the spray.
Secure wiring and components with glue/adhesive to prevent disconnection during operation.

Software and calibration

The Arduino sketch:
- Reads analog values from multiple IR flame sensors.
- Implements calibration thresholds by observing value increases when a flame is presented.
- Supports Bluetooth commands from the BT Controller app to control movement, servo, and pump.
- Implements autonomous behavior: when a sensor reading exceeds the calibrated threshold, the robot navigates toward the source and activates the pump/nozzle.
Calibration tips:
- Observe analog readings from each IR sensor while presenting a flame to determine appropriate threshold values.

Testing & troubleshooting tips

Calibrate each IR sensor individually by observing analog readings with a flame present and set thresholds accordingly.
When paralleling DC motors, test direction first. Reverse motor wiring as needed so paired motors rotate the same way.
Verify common ground between all power and signal sources.
Only use the L298N’s 5 V regulator for Arduino + sensors if it can reliably supply the required current; otherwise use a dedicated 5 V regulator or supply.

Deliverables & resources

The presenter states the full code, circuit diagram, and step‑by‑step instructions are available on his website (subtitles gave www.cat.com — likely a placeholder). A purchasable kit/project link is also noted in the video description.

Demo: both phone-controlled and autonomous modes were tested and used to extinguish a flame in the video.

Main speakers / referenced hardware/software

Shahid — presenter / electronics engineer (primary speaker)
Hardware/software referenced: Arduino (Uno-style), L298N driver, HC-05 Bluetooth, IR flame sensors, BT Controller app, relay/MOSFET for pump control