Question

in MSP430 design tutorial

using F5529

in lab 6

If I wanted to blink LED2 (green) every 2 seconds and LED1 (red) every 1 seconds, how would I set it up using Timers and Interrupts? You need not write any code, just explain how you would do it. (Hint: I’m not looking for a long answer here, but you’d have to do something different than what you did in lab).

Answer 1

Ans.

There are two ways solving this issue ,in first method you could use two timers in MSP430 and set the count value of the first for 1s and in the other you can set double the count (for 2sec) and the two leds can be toggled when the interrupt gets fired. Here we used two ISR's and two timers. In the second method we only use one timer ,set its count for triggering every one second ,in the ISR you need to write code such that only when interrupt is fired twice, the green led is toggled(two second) and the red led is toggled on each interrupt.

For keeping in track that the interrupt is fired twice you can use flag variables to store how many times the interrupt is fired and only on second consecutive firing the green led is toggled. For red led you could toggle it in each interrupt trigger. It is more challenging to do with only one timer and it is also more efficient. Please do try both the methods.