Utilize SW3 of the explorer 16 board to change the direction of the Knight Rider Pattern. Any time, if SW3 is pushed down and hold, the above pattern starts from LEFT to RIGHT and when SW3 is released, the pattern walks from RIGHT to LEFT.
Is my code below correct?
void main(void) {
TRISA = 0x00;
LATA = 0x00;
while(1) {
int i;
int j;
// Right to Left sequence
for(int i=0; i<8; i++) {
LATA = (1 << i);
delayFunc();
}
// Left to Right sequence if SW3 is pressed
if(PORTDbits.RA5 == 0) {
for(j=7; j>=-1; j--) {
LATA |= (1<<j);
delayFunc();
}
}
}
return -1;
}
void delayFunc(void){
int i, j, k;
for(i = 0; i < 1000; i++){
for(j=0; j < 20; j++){
k = j;
}
}
}
No, your code is not correct. There are several issues:
1. The for loop in the main function should be `for(int i=0; i<=8; i++)` instead of `for(int i=0; i<8; i++)`. This is because you want the loop to run for 8 iterations, including the last iteration where `i` equals 8.
2. In the if condition `if(PORTDbits.RA5 == 0)`, you should check if `SW3` is pressed and held down, not just if it is released. So the condition should be `if(PORTDbits.RA5 == 1)`.
3. The loop in the left to right sequence should start from `j=6`, not `j=7`. This is because `j` should be the index of the leftmost LED, which is at index 6 in a 7-segment display.
4. In the left to right sequence, you should use `LATA &= ~(1<<j);` instead of `LATA |= (1<<j);`. This is because you want to turn on the LEDs one by one, not turn them off one by one.
5. You should place the `delayFunc();` function call inside the for loop in both sequences, not outside the loop. This is because you want to delay the execution after each LED is turned on, not after the entire sequence is completed.
Here is the updated code:
```c
void main(void) {
TRISA = 0x00;
LATA = 0x00;
while(1) {
int i;
int j;
// Right to Left sequence
for(int i=0; i<=8; i++) {
LATA = (1 << i);
delayFunc();
}
// Left to Right sequence if SW3 is pressed and held
if(PORTDbits.RA5 == 1) {
for(j=6; j>=-1; j--) {
LATA &= ~(1<<j);
delayFunc();
}
}
}
return -1;
}
void delayFunc(void){
int i, j, k;
for(i = 0; i < 1000; i++){
for(j=0; j < 20; j++){
k = j;
}
}
}
```
There are a few issues with your code. Here are the corrections:
1. In the for loop to go from Left to Right, the condition should be `i>=-1` instead of `j>=-1`. Additionally, you need to use `i--` instead of `j--` to decrement the value of i.
2. The if condition to check if SW3 is pressed should be `if(PORTDbits.RD5 == 0)` instead of `if(PORTDbits.RA5 == 0)`. The switch is connected to port RD5, not RA5.
3. In the delayFunc, the inner for loop should be `for(j=0; j < 200; j++)` instead of `for(j=0; j < 20; j++)` to get a longer delay period.
Here's the corrected code:
```c
void main(void) {
TRISA = 0x00;
LATA = 0x00;
while(1) {
int i;
// Right to Left sequence
for(i=0; i<8; i++) {
LATA = (1 << i);
delayFunc();
}
// Left to Right sequence if SW3 is pressed
if(PORTDbits.RD5 == 0) {
for(i=7; i>=-1; i--) {
LATA = (1 << i);
delayFunc();
}
}
}
return -1;
}
void delayFunc(void){
int i, j, k;
for(i = 0; i < 1000; i++){
for(j=0; j < 200; j++){
k = j;
}
}
}
```
Please note that this code assumes that you have already properly configured the necessary registers and ports for the Explorer 16 board.
The code you provided has a couple of issues. First, the variable `i` is declared as an `int` inside the for loop, even though it is already declared outside the loop. This will result in a compile-time error because the variable is being redefined within the same scope.
To fix this issue, you can simply remove the declaration of `int i` inside the for loop:
```c
for(i = 0; i < 8; i++) {
```
Another issue is with the loop condition in the left-to-right sequence. The condition `j>=-1` will never be true because `j` is initialized to 7, and it will decrement towards negative numbers until it reaches the minimum value of the `int` data type, causing an infinite loop.
To fix this issue, you can change the loop condition to `j >= 0`:
```c
for(j = 7; j >= 0; j--) {
```
Additionally, in the `if` condition to check if SW3 is pressed (`if(PORTDbits.RA5 == 0)`), you should use `PORTDbits.RD6` instead of `PORTDbits.RA5` because SW3 is connected to RD6 (RA5 is the pin used for LEDs). So the corrected `if` condition should be:
```c
if(PORTDbits.RD6 == 0) {
```
Overall, the corrected code should look like this:
```c
void main(void) {
TRISA = 0x00;
LATA = 0x00;
while(1) {
int i;
int j;
// Right to Left sequence
for(i = 0; i < 8; i++) {
LATA = (1 << i);
delayFunc();
}
// Left to Right sequence if SW3 is pressed
if(PORTDbits.RD6 == 0) {
for(j = 7; j >= 0; j--) {
LATA |= (1 << j);
delayFunc();
}
}
}
return -1;
}
void delayFunc(void) {
int i, j, k;
for(i = 0; i < 1000; i++) {
for(j = 0; j < 20; j++) {
k = j;
}
}
}
```
Remember to configure the necessary pins and enable the proper interrupt handling for input switches before executing the code on the actual hardware.