Team Alpha
Obstacle Avoidance
Welcome to Obstacle Avoidance
This page will take you through everything you need to know on how we achieved obstacle avoidance on our micromouse outlining what we did and the processes that took place identifying all the problems and how we dealt with them.
Firstly, the infrared sensor circuit was constructed onto the breadboard with the help of the schematic diagram, which was provided on the micro mouse handout. The integrated circuit was a CD4093 quadruple 2-input Schmitt NAND gate. The difficulties in implementing this circuit to the board was that we had started making the board in a rather unorganised way with long connecting wires which got confusing when trying to see which pin connected to which, due to the use of excess wires we also had less power making its way to the LEDS. To rectify this, we remade the circuit using less wires and in a more organised manner, the circuit then worked perfectly.
To ensure the board was correctly laid out as per the handout, we checked that the microprocessor was outputting all the correct waveforms. Furthermore, to ensure whether the lights were switching on and off at different points. However, to clarify this, we used the waveforms, which were shown in the handout as a helping hand, to compare with our waveforms.
Once the circuit was tested, the circuit was able to produce the right waveforms along with the LED’s being switched on when a surface was close enough. Thus, we knew the circuit was working properly; hence, we proceeded to design the PCB.
Notes on the overall design of the PCB:
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As seen to the left the proteus PCB design is made to fit on half the board so that if we were to want 4 sensors, we could very easily mirror the board, alongside this the more compact design looks a lot cleaner and allows a more slimline robot.
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The two rectangular cut outs were initially for the wheels so that we could make the robot as low as possible however we decided we did not need them and just cut the PCB to its smallest size possible as seen below
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Overall, we are very happy with the design and it works well.
Once the PCB was printed, we were expected to cut out and sand down the edges so that we could have a cleaner finish on the cut rather than proceeding to cut it out after mounting the different components. Our original PCB had a problem because the microprocessor was soldered directly to the board, thus causing the pads to come off.
However, we had resolved this problem with the second PCB. An unusual case with our board is the sensors. Our sensors are bent over, and this is done because of the flipped Proteus design.
Because of the smaller design it allows us to tuck in the wires behind the PCB meaning there are no trailing wires and wires that are going outside the width of the robot which allows a more snug fit when putting on the case meaning a cleaner finish can be achieved.
The PCB was complete, and we were delighted with the final product. The PCB was mounted to the mouse and was then tested in the laboratory where the micro mouse was marked based on the workings of the touch bard and sensors.