Question 1 how many digital inputs are available on the mbed

Question 1. how many digital inputs are available on the mbed?

(a) 13

(b) 26

(c) 5

(d) 30

(e) None of (a) through (d) is the correct answer.

Question 2. the following loop in an mbed program is untidily coded however correct in both syntax and logic, provided that redled and greenled are both correctly configured in other part of the program. What is the total period of the loop?

while (1) {

redled = 0;

wait_ms(12);

greenled = 1;

wait(0.002);

greenled = 0;

wait_us(24000);

}

(a) 36.2 ms (b) 38 ms (c) 12.242 ms (d) 16.4 ms

(e) None of (a) through (d) is the correct answer.

Question 3. LEDs can be directly driven from the mbed digital output. (Points: 5)

       (a) True

       (b) False

Question 4. whenever the mbed pin cannot provide enough power to drive an electrical load directly, interface circuits must be used. And for simple on/off switching a transistor is often all that is needed. (Points: 5)

       (a) True

       (b) False

Solution

1) There will be 26(p5-p30) IO pins on mbed which can be configured as input or output. Therefore the answer is B.
2) answer is 38ms option B
3) true. As they are specifically configured for output with no extra wiring.
4)false, driver circuits must be used.