Construction and testing
A single-side PCB of the main module is shown in Fig. 6 and its component layout in Fig. 7.
A single-side PCB of the RF remote module is shown in Fig. 8 and its component layout in Fig. 9.
Download PCB and Component Layout PDFs: Click here
Download Source Code: Click here
A single-side PCB of the sensor module is shown in Fig. 10 and its component layout in Fig. 11.
You can also assemble the circuit on a general-purpose PCB. Before mounting the MCUs on PCBs, burn respective codes into MCUs using a suitable programmer board.
After mounting all components on PCBs, switch on the power supplies of respective units.
At the main module (robot), initially four LED indicators glow on even pins of PORTB of IC2 by default, and the robot waits for the signal from RF remote. You can also test all the LEDs by pulling port PD6 of IC6 low through DIP1 switch.
For manual mode there are two joysticks connected at ADC channels of the controller (PC0 and PC1) at remote module. By using the joystick, robot movements can be controlled.
Move your robot towards the fire source. Pull PD5 of IC6 to low through DIP1 switch to switch on the water pump.
For troubleshooting the circuit, check to ensure voltages at various test points are as per Table II.
1. By replacing IR photo sensors with the thermal image-processing camera, the pump with a fire extinguishing mechanism and by making the body of the robot fire-proof, it can be used for fire extinguishing purposes. It can also be used in assisting fire fighters, thus helping them reach inaccessible places to save more lives.
2. Increasing the number of sensors will improve the resolution and accuracy of the system further.
3. In autonomous mode, it can detect a fire, if any, and extinguish it without any assistance.
4. The RF module makes it possible for the operator to control the robot manually from a distance, thus allowing surveillance facility.
IR photodiodes also react to sunrays, just like fire, since these too contain IR waves, thus allowing the robot to make false judgments. However, the effect of sunlight and other factors is not significant if we use better sensors (which are far more costly).
To improve the system:
1. Use more sensors such as smoke detectors, temperature sensors and thermal image processing for feedback and to improve the accuracy and reliability of the system further.
2. Replace IR photo sensors with more dependable ones, which have filters, because IR sensors even take sunlight as a source of IR waves, leading to errors and false alarms.
Amol Gulhane is B.Tech (electronics and telecommunication) from College of Engineering Pune, and is co-founder of Robolab Technologies