Can someone please help me, Every time before the booms move they jerk and then go down smoothly the same before the come up. I am using an Arduino UNO. The servos are connected to a speperate 5v supply and the arduino is connected to a seperate 7v supply.
#include<Servo.h>;
int maxPos1 = 45;
int maxPos2 = 45;
int minPos1 = 3;
int minPos2 = 9;
int pos1 = 45;
int pos2 = 45;
byte upPin = 2;
Servo servo1;
Servo servo2;
void setup() {
pinMode(2, INPUT);
servo1.attach(11);
servo2.attach(9);
}
void loop() {
while (digitalRead(upPin) == LOW) {
pos1++;
if (pos1 >= maxPos1) {
pos1 = maxPos1;
}
pos2++;
if (pos2 >= maxPos2) {
pos2 = maxPos2;
}
servo1.write(pos1);
servo2.write(pos2);
delay(40);
}
while (digitalRead(upPin) == HIGH) {
pos1--;
if (pos1 <= minPos1) {
pos1 = minPos1;
}
pos2--;
if (pos2 <= minPos2) {
pos2 = minPos2;
}
servo1.write(pos1);
servo2.write(pos2);
delay(40);
}
}
Greatnorthern:
Can someone please help me, Every time before the booms move they jerk and then go down smoothly the same before the come up. I am using an Arduino UNO. The servos are connected to a speperate 5v supply and the arduino is connected to a seperate 7v supply.
Thanks for all your suggestions. The input to the Arduino is from a PLC relay output. I disconnected the PLC and shorted out the input, problem solved. There is no bounce at the start of the cycle. How can I modify the code so that I do not get this bounce at the start of the boom cycle using the relay output from the PLC.
Greatnorthern:
How can I modify the code so that I do not get this bounce at the start of the boom cycle using the relay output from the PLC.
When you detect a low on the input, move the servos until they both reach their maximum values. Afterwards, when you detect a high on the input, move the servos until they both reach their minimum values. Have the while () loops check the values of pos1 and pos2, not the state of the input, the input is only used to select when to run the while() loop. Note that this is not a good way to do it if you ever want to have the arduino do any additional tasks, because it will block execution of the remaining code until the full servo movement is completed (your original code also has this problem).
so the poor's man way to remove bouncing is to just use a delay() [after you detect the condition] that is long enough for the bounces to go away. in your code above you had 40ms delay (due to your move of the servo) and with most buttons that's plenty but seems not the case for you. You could try to increase this a bit to 60 or 100 and see how it goes.
Another option is to start the movement only when the jitter is gone. you listen to change in the current HIGH or LOW value and when it's stable for a while (using millis()) you trigger your action. You could also still trigger on change but ignore opposite values if they come "soon" after that first trigger. To implement this a small state machine can help.
You could have a look at the OneButton Library, Matthias Hertel implemented a small finite state machine in there to handle bouncing.
(doc is here)
Another option is the hardware way, add a capacitor next to the "button". This will filter out high frequency bouncing and give you a clean signal.
david_2018:
Have the while () loops check the values of pos1 and pos2, not the state of the input, the input is only used to select when to run the while() loop.
There may be something in that idea.
In the OP's code in the Original Post the servos move as long as the switch is (say) HIGH. But the more usual way to deal with switches is to check when they change from LOW to HIGH and use that change to start something. The code might be something like this
previousSwitchState = switchState;
switchState = digitalRead(switchPin);
if (switchState == HIGH and previousSwitchState == LOW) {
servoMove = 'U';
}
if (switchState == LOW and previousSwitchState == HIGH) {
servoMove = 'D';
}
if (servoMove == 'U') {
pos1 ++;
pos2 ++;
}
else {
pos1 --;
pos2 --;
}
if (pos1 > maxPos1) {
pos1 = maxPos1;
// etc etc
}
servo1.write(pos1);
servo2.write(pos2);
delay(40);
I don't think there is any need for a WHILE as setting the max and min values will prevent the servo going too far.
