Specifications
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CHAPTER 6
DEBUGGING MODULE
The Mobile Manoeuvring Robot has been designed and constructed in such a way for
ease of troubleshooting. An example of this is that the software has been written to
output certain characters through the serial port which can be used to gain
understanding of the actual performance of the robot. The following sections are
written to detail the methods of debugging or troubleshooting the robot when
performance is not desirable.
6.1 Microcontroller Not Working
There are two main reasons for the possible case of the microcontroller not turning on,
either a poor power source or a short circuit on the voltage source lines. The orange
LED on the card12 will determine whether the HC12 is working or not. If the orange
LED is not lit, check the polarity and connection of the battery terminals. If these are
connected properly and securely then it is likely to be either a flat battery, faulty voltage
regulator, or a short circuit from any of the loose wires.
Firstly check the battery, it is easiest to either recharge or connect a different battery to
eliminate this problem. The LM7805 voltage regulator requires approximately 7 to 12
volts at the input to ensure correct operation with a 5 volt output. To test the voltage
regulator, a multimeter can be connected to the output leg. Typically this value will
read 5.04 volts when working correctly. If this voltage is degrading slowly then the
battery is flat or faulty. If there is 5 volts present on this track and is not broken away
from the microcontroller then it is highly likely there is a short somewhere on the robot.
Visually checking wires and contacts is the only way to find most shorts.
6.2 Motors Not Turning
If the microcontroller is on and there is no mechanical output from the robot when the
push button is depressed, then it is likely there is no power supplied to the H-Bridges.
This power comes from a separate supply to the microcontroller and should be 10 – 12
volts. It is connected directly to the top and bottom of the H Bridges. Also ensure all
wires are connected securely between the H-Bridges and the microcontroller and also to
the motors. Ensure H-Bridges are not damaged or burnt out however this is unlikely to