This robot is built using a shadow robot kit and is able to be controlled through a bluetooth connection using the Adafruit Bluefruit app. The robot is designed to avoid collisions with obstacles by continually detecting obstacles using the IR sensor.

The IR sensor will continually search in front of the robot. If a wall is detected, the robot will enter a warning state. When in this warning state, the robot prevents the user from moving forward and issues a warning beep from the speaker on the robot. This beep can be changed to another sound by changing the file stored on the SD card. This beep will continue to sound until the wall in front of the robot is no longer detected. The robot uses an 3-point averaging filter to remove noise from the sensor and implements hysteresis to determine if the obstacle is still there.

The robot is able to receive information from a bluetooth sensor placed on the breadboard and moves according to the arrow button pressed. This button will issue a command to the mBed causing it move by activating the DC motors. The robot will immediately stop the robot when it detects an obstacle in front of it and refuse to allow the user to move forward unless the obstacle is moved, however, the robot will still be able to rotate and reverse.

ECE 4180 Lab 4

• Vasundhara Rawat
• Nashwin Bharwani

Materials

• mbed LPC1768
• Distance (IR) sesnor
• 2 DC motors
• H-bridge
• Bluetooth device
• Speaker
• Speaker Amplifier (TPA2005D1)
• SD card reader
• 2 external 5 V power supply

Connections