ME3040 Homework 3

Servo    Pin 0
Photo1    Pin 1
Photo2    Pin 2
Photo3    Pin 3
Red LED    Pin 4
Problem 1
Write a pbasic program to control a servo-controlled platform (See Figure below). The platform is to be used to orient a solar panel to capture the most solar energy possible during the day. Three photoresistors (Photo1, Photo2, and Photo3) will be mounted at full-clockwise, center, and full-counterclockwise servo positions, respectively to provide light intensity information to the BS2. The BS2 program must:
(1)    Read the light intensity information from each photoresistor.
(2)    Move the servo (platform) to point in the direction where the light is most intense.
(3)    If all three photoresistors read values that are too dark (high RC time values) above a prede ned threshold (assume the threshold is a RC discharge time value of 200 µs), the BS2 must turn on a red LED to alert the operator that there is not enough light to capture.
Assume the following pin connections: 

Problem 2
Write a pbasic program to control a servo-controlled entrance/exit gate. The gate consists of an entrance/exit barrier which is controlled by a servo (Servo1). For design simplicity, assume that the servo is originally in its center position when the gate is CLOSED. When set to OPEN, the servo should turn 90 degrees counterclockwise (to its full-counterclockwise position).
An ID scanner is used to allow access in (i.e., turn Servo1 to OPEN position). Assume the ID scanner sends a TRUE (1) signal to the BS2 if the ID is valid, and a FALSE (0) signal otherwise. Once the gate opens, it must remain open for 20 seconds to allow the person time to enter the gate. An ultrasonic sensor is also added as a safety measure to detect the presence of a person at the gate. Once the 20 seconds elapse, if the ultrasonic sensor still detects a person at a distance shorter than 3 ft from the gate, the gate will remain open. In this case, a red LED should also turn on to alert the security guard that the gate is being held open.
Finally, the security guard at the gate can override both the ID scanner and the ultrasonic sensor by using a push-button (PB1) to OPEN the gate inde nitely and a separate push-button (PB2) to CLOSE the gate.
Assume the following pin connections:
Servo1    Pin 0
ID Scanner    Pin 1
Ultrasonic Sensor    Pin 2
Red LED    Pin 3
PB1    Pin 4
PB2    Pin 5
 
Problem 3
For the pneumatic circuit below, write a paragraph describing the circuit operation, including the name and function of each individual component.
 
Problem 4
Determine the sequence of operation of the pneumatic circuit shown in the gure below. Explain in detail, which valve is activated at each stage in the sequence.
 

Attachment

• ME3040 Homework 3.docx (280 KB)