i would like to know how to write
if ( value == 3 "for 2 seconds") {
Serial.print("whatever");
}
Thinking in terms of state machines helps to solve these kinds of problems.
The attached state diagram results in this code
void setup(){
Serial.begin(115200);
}//setup()
int acceptorState;
int Value;
unsigned long mark;
void loop(){
switch(acceptorState){
case 0://initial state
if(Value==3){
acceptorState = 1;
mark = millis();
}
break;
case 1://eval state
if(millis()-mark>1999) acceptorState = 2;//Value has been 3 for 2000ms or more, go to accept state
if(Value!=3) acceptorState = 0;//Value has changed, back to init state
break;
case 2://value accepted
Serial.println("value accepted");
}//switch(acceptorState)
}//loop()
Another way is to re-formulate the problem as:
if ( value == 3 && it has been 2 seconds since the value changed) {
Serial.print("whatever");
}
That can be written:
unsigned int valueChangeTime;
.
.
.
value = 3;
valueChangeTime = millis();
.
.
.
if ( value == 3 && millis() - valueChangeTime > 2000) {
Serial.print("whatever");
}
johnwasser:
Another way is to re-formulate the problem as:if ( value == 3 && it has been 2 seconds since the value changed) {
Serial.print("whatever");
}
That does only check if value is the same as 2 seconds ago, it could have changed and changed back during that time
I think I would do this "the other way around" - by resetting the timer every time the button is unpressed
void loop() {
buttonState = digitalRead(buttonPin);
if (buttonState == HIGH) {
startTime = millis();
}
if (millis() - startTime >= interval) {
// do whatever
}
}
...R
first of all thanks for your suggestions but if i have something like this and i need the values to be checked for 2 seconds, how your suggestions will be implemented?
void s() {
int x = analogRead(xpin);
int y = analogRead(ypin);
int z = analogRead(zpin);
if (x<445&&x>310){
if (y<401&&y>380){
if (z<370&&z>360){
sv = sv + 1;
rv = rv + 1;
count = count + 1;
Serial.println();
Serial.print("position confirmed");
}
}
}
}
You forgot to say which 'value' should be unchanged for two seconds. Since sv, rv, and count all change together I guess it doesn't matter which I pick.
void s() {
static unsigned long timeOfLastChange;
int x = analogRead(xpin);
int y = analogRead(ypin);
int z = analogRead(zpin);
// Logically equivalent to your nested IF statements
if ((x<445&&x>310) && (y<401&&y>380) && (z<370&&z>360)) {
sv = sv + 1;
rv = rv + 1;
count = count + 1;
Serial.println();
Serial.print("position confirmed");
}
if (sv != oldsv) { // Value has changed
timeOfLastChange = millis();
oldsv = sv;
}
if (millis() - timeOfLastChange > 2000) {
// Value has not changed in two seconds
}
}
if (value == 3)
{Serial.write ("let me know when 2 seconds has passed");
while(!Serial.available())
Serial.println("Are we nearly there yet?");
Serial.write("Thank you");
}
johnwasser:
You forgot to say which 'value' should be unchanged for two seconds. Since sv, rv, and count all change together I guess it doesn't matter which I pick.void s() {
static unsigned long timeOfLastChange;
int x = analogRead(xpin);
int y = analogRead(ypin);
int z = analogRead(zpin);
// Logically equivalent to your nested IF statements
if ((x<445&&x>310) && (y<401&&y>380) && (z<370&&z>360)) {
sv = sv + 1;
rv = rv + 1;
count = count + 1;
Serial.println();
Serial.print("position confirmed");
}
if (sv != oldsv) { // Value has changed
timeOfLastChange = millis();
oldsv = sv;
}
if (millis() - timeOfLastChange > 2000) {
// Value has not changed in two seconds
}
}
sorry for forgetting to specify the values. the values i need to be true for 2 sec are the x,y,z values
if (x<445&&x>310){
if (y<401&&y>380){
if (z<370&&z>360){
KenF:
if (value == 3)
{Serial.write ("let me know when 2 seconds has passed");
while(!Serial.available())
Serial.println("Are we nearly there yet?");
Serial.write("Thank you");
}
thats not what i meant, your code says if the value is = 3 start a timer for 2 seconds and when is the 2 seconds are done , print to serial.
what i want is, if the value is = 3 for 2 seconds, print to serial in may case
if (x<445&&x>310){
if (y<401&&y>380){
if (z<370&&z>360){
all of x,y,z are between these specified values for 2 seconds, "do whatever"
The state machine approach still holds. Enter the "Eval" state when all three values are inside the required intervall and go back to "Init" state as soon as any of them fall outside the intervall.
tried this but instead of waiting for 2 seconds all the commands the i have specified in void loop was immediately executed
const int xpin = A3;
const int ypin = A2;
const int zpin = A1;
int acceptorState;
int Value;
unsigned long mark;
void r() {
int x = analogRead(xpin);
int y = analogRead(ypin);
int z = analogRead(zpin);
switch(acceptorState){
case 0://initial state
if (x<445&&x>310){
if (y<401&&y>380){
if (z<370&&z>360){
acceptorState = 1;
mark = millis();
}
}
}
break;
case 1://eval state
if(millis()-mark>1999) acceptorState = 2;//Value has been 3 for 2000ms or more, go to accept state
if((x>445&&x<310)&&(y>401&&y<380)&&(z>370&&z<360)) acceptorState = 0;//Value has changed, back to init state
break;
case 2://value accepted
Serial.print("value accepted");
}//switch(acceptorState)
}//loop()
(y>401&&y<380)
How many values can y have that are greater than 401 and less than 380?
Or:
z>370&&z<360)
z is both greater than 370 and less than 360?
Well spotted, PaulS!
@OP: Try using some spaces, it doesn't have to look like random garbage.
z > 370 && z < 360)
at the beginning these are the ranges that i want:
if (x < 445 && x > 310){
if (y < 401 && y > 380){
if (z < 370 && z > 360){
but in order to say that if the x,y or z values exceed these limits i should invert it
if((x > 445 && x < 310)&&(y > 401 && y < 380)&&(z > 370 && z < 360))
in other words :
if x is greater than 310 and less than 445 : start the counter and if during the counter the x value exceeded 445 or became less than 310 reset the timer and start from the beginning, got it?
if (x < 445 && x > 310){
Doesn't it make more sense to express that naturally?
if (x > 310 && x < 445){
That is, after all, the way most people think.