Super 2001 Train Controller (AVR)
A simple way to keep people interested in learning is to have them work with familiar systems in new and interesting ways. Our idea was to design a project that could be used as an instructional tool for student, away to learn about micro-controllers without the monotony of standard design projects. The train controller allows students to get hands on experience with programming the Atmel 90s8515, while exploring the concepts of analog design, such as isolation of power supplies using inductors and opto-couplers, motor control, sensor design, and signal control.
In order to detect where the train was on the track, optical sensors were placed at four points on the track. Each of these sensors was an infra-red (IR) emitting diode and photo-transistor pair. The sensors output a logical 0 when there was no train present and a logical 1 while the train was breaking the beam. This was accomplished because the LED constantly emitted a beam into the optical base of the photo-transistor, so the transistor was on except while the beam was being broken. The output of the transistor was buffered using a Burr-Brown OPA2350 op-amp, and then connected to both the port pin on the Atmel 90s8515 (PORTA[0..4}) and to 4 green LED's to allow us to visibly ensure the sensors were working properly..
Link: http://instruct1.cit.cornell.edu/courses/e...01/chadballard/
A simple way to keep people interested in learning is to have them work with familiar systems in new and interesting ways. Our idea was to design a project that could be used as an instructional tool for student, away to learn about micro-controllers without the monotony of standard design projects. The train controller allows students to get hands on experience with programming the Atmel 90s8515, while exploring the concepts of analog design, such as isolation of power supplies using inductors and opto-couplers, motor control, sensor design, and signal control.
In order to detect where the train was on the track, optical sensors were placed at four points on the track. Each of these sensors was an infra-red (IR) emitting diode and photo-transistor pair. The sensors output a logical 0 when there was no train present and a logical 1 while the train was breaking the beam. This was accomplished because the LED constantly emitted a beam into the optical base of the photo-transistor, so the transistor was on except while the beam was being broken. The output of the transistor was buffered using a Burr-Brown OPA2350 op-amp, and then connected to both the port pin on the Atmel 90s8515 (PORTA[0..4}) and to 4 green LED's to allow us to visibly ensure the sensors were working properly..
Link: http://instruct1.cit.cornell.edu/courses/e...01/chadballard/