So I'm building a simple MikroC program that sets PORTB.B0 if PORTA.B0 is equaled to 1
void main() {
PORTA.B0=1;
while(1){
if(PORTA.B0){
PORTB.B0=1;
}
}
}
However it doesn't give me anything PortB.B0 isn't equal to 1 only portA.
Can anyone help?
According to your code you, you must have initialized the direction of the portb.rb0 and porta.ra0 bits as output and input respectively. Also you need to give a little delay for de-bouncing.
void main()
{
ANSEL=0x00;
trisa.ra0=1; //for input
trisb.rb0=0; //for output
while(1)
{
if (porta.ra0)
{
portb.rb0=1; // setting high
delay_ms(300); // time to stabilize mechanical button
}
}
}
Just try if(PORTA.B0==1). This should work.
Related
i am trying to make a stopwatch and counter project for arduino. Code aside, is this wired correctly?
The top button is to start the stopwatch, second is the button to start the counter (every press increases by one), and the bottom button should be to reset any of them. the green light is to show the stopwatch is selected and blue is to show the counter is selected. the lcd is to display everything obviusly. Also, what is the best way to learn to code this and how long would it take? Thanks.
This is the code as per your requirement. I have defined pins as per above connections. counter mode has minutes and seconds and it does not contain milliseconds as I am encountering problem to implement it. You can suggest me if you have got any way. Counter mode selection button is the same button which is going to be used to increment the counter.
#include <LiquidCrystal.h>
LiquidCrystal mylcd(7,6,5,4,3,2);
int counter_sel=12,stopwatch_sel=11,reset1=10,stopwatch_led=9,counter_led=8;
void setup()
{
mylcd.begin(16,2);
mylcd.setCursor(0,0);
mylcd.print("Counter and ");
mylcd.print("Stopwatch");
delay(1000);
pinMode(counter_sel,INPUT);
pinMode(stopwatch_sel, INPUT);
pinMode(reset1, INPUT);
pinMode(counter_led,OUTPUT);
pinMode(stopwatch_led, OUTPUT);
}
void loop()
{ int state1=digitalRead(counter_sel);
int state2=digitalRead(stopwatch_sel);
if (state1==0) {delay(300); counter(); } // call counter function
else if (state2==0) {delay(300); stopwatch(); } // call stopwatch function
}
void counter()
{ mylcd.clear();
digitalWrite(counter_led,1);
mylcd.setCursor(0,0);
mylcd.print("Counter Mode :");
short int i=0;
while(1)
{
int rst=digitalRead(reset1);
if (rst==0) { delay(300); break;}
int state1=digitalRead(counter_sel);
if (state1==0) { i++; delay(200);}
mylcd.setCursor(0,1);
mylcd.print(i);
}
digitalWrite(counter_led,0);
}
void stopwatch()
{
mylcd.clear();
digitalWrite(stopwatch_led,1);
long int ms=millis();
byte sec=0, mins=0;
mylcd.setCursor(0,0);
mylcd.print("Stopwatch Mode : ");
while(1)
{
mylcd.setCursor(0,1);
int state1=digitalRead(reset1);
if (state1==0){delay(300); break; }
if (sec==59) {mins++; sec=0;}
if ((millis()-ms)>1000) {sec++; ms=millis(); }
mylcd.print(mins);
mylcd.setCursor(3,1);
mylcd.print(":");
mylcd.setCursor(5,1);
mylcd.print(sec);
mylcd.print(":");
//mylcd.print(millis()-ms);
}
digitalWrite(stopwatch_led,0);
}
As much as I can see, and considering what you explained above, the connections are correct. But the thing is you need to make it clear as much as you can, because due to intersecting point in LCD connection, it would be very much harder to debug and resolve the connection problem, for that you must make it neat. To learn to code this stuff there is no rocket science, just use your wisdom, and start reading books, blogs, articles on arduino ide(which is too simple too use), c programming and microcontrollers , and youtube videos are the great source to learn to code, you should have handful experience of c programming, that's all.
I have been having a problem with this code for a while. The placement of recursive call of the function does not seem right.
i tried running the code and yes it does run into a infinite loop.
// I DEFINE HEAP STRUCTURE AS :
struct heap_array
{
int *array; // heap implementation using arrays(note : heap is atype of a tree).
int capacity; // how much the heap can hold.
int size; //how much size is currently occupied.
void MaxHeapify(struct heap_array *h,int loc) // note : loc is the location of element to be PERCOLATED DOWN.
{
int left,right,max_loc=loc;
left=left_loc_child(h,loc);
right=right_loc_child(h,loc);
if(left !=-1 && h->array[left]>h->array[loc])
{
max_loc=left;
}
if(right!=-1 && h->array[right]>h->array[max_loc])
{
max_loc=right;
}
if(max_loc!=loc) //i.e. if changes were made:
{
//swap the element at max_loc and loc
int temp=h->array[max_loc];
h->array[max_loc]=h->array[loc];
h->array[loc]=temp;
}
MaxHeapify(h,max_loc); // <-- i feel that this recursive call is misplaced. I have seen the exact same code in almost all the online videos and some books i referred to. ALSO I THINK THAT THE CALL SHOULD BE MADE WITHIN THE SCOPE OF condition if(max_loc!=loc).
//if no changes made, end the func right there.
}
In your current implementation, it looks like you don't have a base case for recursion to stop.
Remember that you need a base case in a recursive function (in this case, your MaxHeapify function), and it doesn't look like there is one.
Here is an example of MaxHeap which may be resourceful to look at
// A recursive function to max heapify the given
// subtree. This function assumes that the left and
// right subtrees are already heapified, we only need
// to fix the root.
private void maxHeapify(int pos)
{
if (isLeaf(pos))
return;
if (Heap[pos] < Heap[leftChild(pos)] ||
Heap[pos] < Heap[rightChild(pos)]) {
if (Heap[leftChild(pos)] > Heap[rightChild(pos)]) {
swap(pos, leftChild(pos));
maxHeapify(leftChild(pos));
}
else {
swap(pos, rightChild(pos));
maxHeapify(rightChild(pos));
}
}
}
Here, you can see the basecase of:
if (isLeaf(pos))
return;
You need to add a base case to your recursive function.
I need help with an Arduino sketch , I want to repeat the blink sketch for a specified amount of time (3minutes for example) , then Stop .As we know , the loop() keeps runing forever which is not what I want . Any ideas how I can achieve this , blinking an LED for X minutes and Stopping ?
You should probably make use of some timer library. A simple (maybe naive) way to achieve what you want to do is to make use of a boolean that is set to 0 when 3 minutes has passed or simply digitalWrite the led to low when the timer has passed.
Check this link:
http://playground.arduino.cc/Code/Timer
I suggest that you use int after(long duration, callback).
Below is a (very) simple example of how you probably could do:
#include "Timer.h"
Timer t;
LED = 1;
void setup() {
int afterTime = t.after(180000, cancelLED);
}
void loop() {
t.update();
if(LED) {
//The "write HIGH" statement in your sketch here.
}
else {
//Write the led to LOW
}
}
void cancelLED() {
LED = 0;
}
I haven't used the library myself, I just checked the the docs and wrote an example to give you some ideas. Don't expect it to work right away.
I'm trying to work with a simple Arduino circuit that increments a counter variable on pressing a push button in the circuit (connected as INPUT to PIN 8). My code is as simple as follows:
#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int c = 0, btnPIN, btnVal;
void setup ()
{
btnPIN = 8;
pinMode(btnPIN, INPUT);
lcd.begin(16,2);
lcd.clear();
}
void void loop()
{
btnVal = digitalRead(btnPIN);
if (btnVal == LOW)
{
c++;
lcd.clear();
lcd.print(c);
}
}
Problem is the counter increases by more than 1 every time I push the button. A little bit of printing on the serial monitor indicates that each time the button is pressed and the voltage is LOW, the conditional code is executed multiple times and the counter increases by multiple times instead of 1.
Maybe, I need to write some logic that checks if the button was initially unpressed, then pushed and then released again and then these steps would trigger the required action.
The solution I'm currently working with is as under (which works just fine):
int btnStatus = 0;
void loop()
{
btnVal = digitalRead(btnPIN);
if (btnVal == LOW)
btnStatus = 1;
if(btnStatus == 1 && btnVal == HIGH)
{
c++;
lcd.clear();
lcd.print(c);
btnStatus = 0;
}
}
I'm not sure if there's a simpler solution available or if this approach is wrong for other reasons? Any advice would be most welcome!
Another problem you you may be having is that mechanical buttons bounce. That is, they jump between two positions several times quickly before settling to a final position. This is standard operation so it is necessary to "debounce" the button.
There are very many ways to do this, but Here is a tutorial using an Arduino.
The main issue, as you probably figured out, is that the loop function is getting called multiple times while the button is down. This is what is fixed by your code, and yours looks to be a good solution and I don't really see a simpler way. For another way, though, perhaps you could try just adding a call to delay at the end of loop to slow it down a bit. You would have to play with the delay amount a bit, but it could work. Really though, your solution looks just fine.
Your idea is correct, you need to track the previous state of the button to know if it is a new press or if it is simply being held down. Your code could be rewritten to look more like a state machine, however:
typedef enum {
BTN_STATE_RELEASED,
BTN_STATE_PRESSED
} ButtonState;
ButtonState btnStatus = BTN_STATE_RELEASED;
void increment_counter()
{
c++;
lcd.clear();
lcd.print(c);
}
void loop()
{
btnVal = digitalRead(btnPIN);
switch(btnStatus)
{
case BTN_STATE_PRESSED:
// Handle button release
if(btnVal == HIGH)
{
btnStatus = BTN_STATE_RELEASED;
}
break;
case BTN_STATE_RELEASED:
// Handle button press
if(btnVal == LOW)
{
increment_counter();
btnStatus = BTN_STATE_PRESSED;
}
break;
}
}
This was rewritten to use an enum to track the state of the system (a bit overkill for a simple button, but an important concept to know in case your system grows more complex).
The code to update the display was also moved into its own function to make it better separated between the display change and the actual update of the state.
In QT have the following code that starts a thread to send out commands. The thread takes a char * and int as arguments. In the "run" I use the pointer that is given by the constuctor. The code is:
MyThread::MyThread(char * payld, int payld_size)
{
payload_size = payld_size;
payload_p = payld;
}
void MyThread::run()
{
while(...)
{
sendCommand(payload_p, payload_size);
}
}
Unfortunately this doesn´t work and my application crashes when I try to use thread.start(). But when I change it to:
MyThread::MyThread(char * payld, int payld_size)
{
payload_size = payld_size;
payload_p = payld;
for(int i=0; i<payload_size; i++)
{
payload[i] = payld[i];
}
}
void MyThread::run()
{
while(...)
{
sendCommand(payload, payload_size);
}
}
The code does run and only crashes sometimes (looks pretty random to me). Can anybody Explain me why version one doesnt work and version two does? And any ideas on why the second code sometimes crashes? Could it be because the size of payload is not predefined (in the header file I defined it as
char payload[];
When I define it as:
char payload[10];
it seems to work better, but it is annoying to test since the crashes are pretty random.
instead of fiddling with char*, I would switch to QString (since you're using Qt). It takes a bit of learning, but it's almost mandatory to get code working smoothly in this framework. Then declare
QString payload;
and depending on sendCommand implementation, use one of the member functions QString to get the char*, like payload.toLatin1()