To develop an automated vehicle that would follow black electrical tape lines placed on the Austin lab floor.
Features of Controller
I am using the clocks, I/O pins, and ADC10 on the MSP430G2231 Chip. This chip is attached to the Launchpad board. The MSP430G2231 chip can be powered from 1.8V to 3.6V, has a 16-Bit RISC Architecture, and can handle clock rates of to 16MHz. It also has a 16 bit timer, and a 10-Bit 200ksps A/D converter.
Hardware Design
Schematic:
OPB742 Emitter and Detector
OPB742 Emitter and Detector
Description: Power: A 7.5V nickel-metal-hydride battery is attached to both a 3.3V and 5.0V regulator. The 5V regulator provides power to the L293NE Dual H-Bridge and the IR LEDs in the OPB742 emitter and detector package. The 3.3V regulator powers the detectors in the OPB742 emitter and detector package and also the MSP430 chip. The 7.5V from the battery are also connected to the L293NE’s motor power pin to power the two geared DC motors that drive the car’s two wheels.
Logic: With everything powered correctly, the MSP430 will convert the voltages output from the IR light detectors into digital values. This is done on pins 1.1 and 1.3 of the MSP430 by the A/D. Depending on the surfaces the detectors are over, different values will be registered by the MSP430 chip because different amounts of light from the IR emitters will be reflected back into the detectors. The MSP430 will react to the different values by setting the appropriate control pins, connected to the H-bridges, high and low to steer the car along a line placed on the ground. Pins 1.2 and 1.4 go to the H-bridge’s right side control pins and pins 1.5 and 1.7 to the left side control pins. In this case the two enable pins on the H-bridge chip are tied to 5V because they should always be enabled. Pictures: OPB742 Emitters and Detectors
5.0V Regulator
L293NE Chip 3.3V Regulator
MSP430 Chip
Top View
OPB742 Emitters and Detectors
Front View