I am new to Arduino and trying to just create a simple application so a servo goes forward 50 degrees when a button is pushed(not continuous) and when let go of it will go back 50 degrees. For some reason my servo just keeps running. What should I do to debug this.
#include <Servo.h>
Servo myservo; // creating myservo object
int buttonPin = 2;
int servoPin = 3;
int buttonState = 0; // set buttonState
void setup()
{
myservo.attach(servoPin);
pinMode(buttonPin, INPUT);
}
void loop()
{ buttonState = digitalRead(buttonPin); // read and save to the variable "buttonState" the actual state of button
if (buttonState == HIGH)
myservo.write(50); else
myservo.write(0);
}
You should use the Bounce library library to catch the edge's you are looking for. Your script as written is continuously updating the PWM with 50 or 0. It is never getting a chance to actually do it. Hence you only want to update it on a change; either depress or release.
I have not tested the below. It does compile and is a simple hack from the examples and your above.
#include <Servo.h>
#include <Bounce.h>
#define BUTTON 2
#define servoPin 3
#define LED 13
Servo myservo; // create servo object to control a servo
Bounce bouncer = Bounce( BUTTON, 5 );
void setup() {
pinMode(BUTTON,INPUT);
pinMode(LED,OUTPUT);
digitalWrite(LED, HIGH);
myservo.attach(servoPin);
}
void loop() {
if ( bouncer.update() ) {
if ( bouncer.fallingEdge()) {
myservo.write(50);
digitalWrite(LED, LOW);
} else if ( bouncer.risingEdge()) {
myservo.write(0);
digitalWrite(LED, HIGH);
}
}
// foo bar...
}
I am going to take a wild guess that you have a continuous rotation servo. These servos have the position feedback from the potentiometer removed/disconnected so when you apply any rotation to the servo it will continuously spin thinking that it is not yet at the desired position. These servos have three control positions: off (likely 90 degrees) clockwise (anything larger than 90) and counterclockwise (anything less than 90). Some do allow you to control speed as well (I think the VEX one you cite having may be one - look up the spec sheet).
I might have my no movement value wrong (it may not be 90) and my counter/clockwise reversed, but I am almost certain this is your issue. Basically your motor is not what you think it is :)
myServo.writeMicroseconds(1500);
This will make it stop if its not broken and its a continuous digital servo.
Related
I am using Arduino UNO and I have 5 MG995 servo motors. But when i test the machine using 1 servo motor, it does not work.
My connections are not wrong. Ports are okay but i don't know why it doesn't work.
My code for one servo motor.
#include<Servo.h> // include server library
Servo ser; // create servo object to control a servo
int poser = 0; // initial position of server
int val; // initial value of input
void setup() {
Serial.begin(9600); // Serial comm begin at 9600bps
ser.attach(9);// server is connected at pin 9
}
void loop() {
if (Serial.available()) { // if serial value is available
val = Serial.read();// then read the serial value
if (val == 'd') { //if value input is equals to d
poser += 1; //than position of servo motor increases by 1 ( anticlockwise)
ser.write(poser);// the servo will move according to position
delay(15);//delay for the servo to get to the position
}
if (val == 'a') { //if value input is equals to a
poser -= 1; //than position of servo motor decreases by 1 (clockwise)
ser.write(poser);// the servo will move according to position
delay(15);//delay for the servo to get to the position
}
}
}
There isn't anything very obvious wrong with the code, as long as you press d more than a so poser stays in range.
to test your hardware, run one of the examples such as sweep.
you should put in limits for poser so it stays between 0 and 180
try also lighting a led when 'a' or 'd' is received so you know that is working
I have a program that lets an LED pulse. I also connected the PC8574 GPIO expander with a push button. I want to evaluate the keypress. However, I can only read the status of the INT (interrupt) while the program is in the part between making the LED brighter and making it darker again (between the two for loops)
I know that the problem is the delays withing the for loops but I have no idea how to avoid that.
Would it be possible to evaluate the interrupt related code more often or like a real interrupt - always when the actual key is pressed? And if so, how?
I use this library: https://github.com/WereCatf/PCF8574_ESP
/*LED_Breathing.ino Arduining.com 20 AUG 2015
Using NodeMCU Development Kit V1.0
Going beyond Blink sketch to see the blue LED breathing.
A PWM modulation is made in software because GPIO16 can't
be used with analogWrite().
*/
#include <pcf8574_esp.h>
#include <Wire.h>
TwoWire testWire;
// Initialize a PCF8574 at I2C-address 0x20, using GPIO5, GPIO4 and testWire for the I2C-bus
PCF857x pcf8574(0x20, &testWire);
#define LED D1 // Led in NodeMCU at pin GPIO16 (D0).
#define BRIGHT 300 //max led intensity (1-500)
#define INHALE 1250 //Inhalation time in milliseconds.
#define PULSE INHALE*1000/BRIGHT
#define REST 1000 //Rest Between Inhalations.
#define PIN_INT D5
#define PIN_SDA D7
#define PIN_SCL D8
//----- Setup function. ------------------------
void setup() {
Serial.begin(115200);
Wire.pins(PIN_SDA, PIN_SCL);//SDA - D1, SCL - D2
Wire.begin();
pinMode(PIN_INT, INPUT_PULLUP);
pcf8574.begin( 0xFF);
pcf8574.resetInterruptPin();
pinMode(LED, OUTPUT); // LED pin as output.
}
bool CheckKey(byte key, byte num){ //0, 1, 2, 3
return key & (1 << num);
}
//----- Loop routine. --------------------------
void loop() {
//ramp increasing intensity, Inhalation:
for (int i=1;i<BRIGHT;i++){
digitalWrite(LED, LOW); // turn the LED on.
delayMicroseconds(i*10); // wait
digitalWrite(LED, HIGH); // turn the LED off.
delayMicroseconds(PULSE-i*10); // wait
delay(0); //to prevent watchdog firing.
}
if( digitalRead(PIN_INT)==LOW ){
delay(50);
byte b = pcf8574.read8();
Serial.println( "INT: " + String(b));
byte keys = ((~b)) & 0x0F;
if( CheckKey(keys, 8) ){
Serial.println( "KEY 7");
delay(2000);
}
}
//ramp decreasing intensity, Exhalation (half time):
for (int i=BRIGHT-1;i>0;i--){
digitalWrite(LED, LOW); // turn the LED on.
delayMicroseconds(i*10); // wait
digitalWrite(LED, HIGH); // turn the LED off.
delayMicroseconds(PULSE-i*10); // wait
i--;
delay(0); //to prevent watchdog firing.
}
delay(REST); //take a rest...
}
You could use the PCF8574 INT pin as an interrupt to the ESP8266 via Arduino's attachInterrupt() function, but you wouldn't gain much from that, since in order to detect which key was pressed you need to call pcf8574.read8(), and you can't do that from the interrupt handler.
The ESP8266 Arduino core is based on the Espressif NONOS SDK, so you can't have a separate thread to monitor key presses. I would suggest defining a helper function that checks if a key is currently being pressed, and then calling that function as often as you can in your main loop, e.g. at every iteration of each of your two for loops. The LED brightness ramps would be slightly disrupted when there is a key press, but I think it wouldn't be noticeable to the human eye.
So the helper function could be defined as:
byte GetKeyPress(void) {
if (digitalRead(PIN_INT) == LOW) {
return ~pcf8574.read8();
}
else {
return 0;
}
}
Then, at the beginning of the loop() function declare a static variable static byte keyPress;, and call the above function in each of the two for loops:
if (keyPress == 0) {
keyPress = GetKeyPress();
}
When you want to process a key press (e.g. between the two for loops like in your code), you can do like that:
if (keyPress) {
/* Do your stuff. */
keyPress = 0;
}
With this code written in the Arduino IDE I used to be able to call functions based on which Infrared sensor detected an object(right, left, or both). I altered the code a little bit lately but I've continued to make sure it wasn't missing any key components which made it work in the first place. I'm not sure if it's an error in my program or hardware but now, no matter what sensor detects an object, my robot just turns slightly to the left.
//Include Servo Library
#include <Servo.h>
//Define Pins for the Sensors and LEDs
#define LsensorPin 8
#define RsensorPin 5
#define LeftTransPin 7
#define RightTransPin 6
I'm using continuous rotation servos so using 0's and 180's is how I would control them at full speed. I checked the numbers over and over but they don't seem to be the problem.
//Constants for driving servo
const int RForward = 0;
const int RBackward = 180;
const int LForward = RBackward;
const int LBackward = RForward;
const int RNeutral = 90;
const int LNeutral = 90; //0 Speed
//Name the Servos for Left and Right Motor
Servo LMotor;
Servo RMotor;
The following 2 functions, when called, transmit an infrared signal through the transmitters. I do not think this is related to the problem because the sensors still detect objects, but my robot just doesn't respond the way I want it to.
//Take Reading from Left IR Sensor
void LeftIRled(){
for(int i=0;i<=384;i++){
digitalWrite(LeftTransPin, HIGH);
delayMicroseconds(13);
digitalWrite(LeftTransPin, LOW);
delayMicroseconds(13);
}
}
//Take Reading from Right IR Sensor
void RightIRled(){
for(int i=0;i<=384;i++){
digitalWrite(RightTransPin, HIGH);
delayMicroseconds(13);
digitalWrite(RightTransPin, LOW);
delayMicroseconds(13);
}
}
These functions control the direction in which the robot moves. I've checked it many times but this could possibly be one of the problems. They basically just control the spin of each individual servo with the previously declared variables.
//Controlling Servo Directions with Functions
void Forward(){
RMotor.write(RForward);
LMotor.write(LForward);
}
void Backup(){
RMotor.write(RBackward);
LMotor.write(LBackward);
}
void Stop(){
RMotor.write(RNeutral);
LMotor.write(LNeutral);
}
void Left(){
RMotor.write(RForward);
LMotor.write(LNeutral);
}
void Right(){
RMotor.write(RNeutral);
LMotor.write(LForward);
}
//Declare INPUT and OUTPUT for each Pin connected
//to Arduino Uno and set them to LOW
void setup(){
pinMode(LeftTransPin, OUTPUT);
digitalWrite(LeftTransPin, LOW);
pinMode(RightTransPin, OUTPUT);
digitalWrite(RightTransPin, LOW);
//drive forward
LMotor.attach(9);
RMotor.attach(10);
Forward();
}
Although I can't pinpoint the problem I believe it has something to do with the loop function. It is here that I transmit the infrared signal, receive it, and then call various functions which control the movement of the robot.
void loop(){
/*Drive forward until you reach an obstacle on either the
right side, left side, or both together(something in front of
you). If the left sensor goes low, he turns right, if the right
sensor goes low, he turns left. if both turn on at the same time
he stops, backs up, and turns right till he is out of danger
*/
int lstate;
int rstate;
LeftIRled();
lstate = digitalRead(LsensorPin);
delay(50);
RightIRled();
rstate = digitalRead(RsensorPin);
delay(50);
if (lstate == LOW && rstate == LOW)
{
Stop();
delay(100);
Backup();
delay(1000);
Stop();
delay(100);
Right();
delay(500);
}
else if (lstate == LOW)
{
Stop();
delay(100);
Backup();
delay(1000);
Right();
delay(500);
}
else if (rstate == LOW)
{
Stop();
delay(100);
Backup();
delay(1000);
Left();
delay(500);
}
else
{
Forward();
}
}
Any help or advice is greatly appreciated!
I have some code controling an old analoge servo and all is working fine.
But when I got a new digital servo, it will not hold position, but return to 0.
Please help, what is needed?
Here is the basic code basen on Sweep:
#include <Servo.h>
Servo myservo;
int pos = 0;
void setup()
{
myservo.attach(A1);
}
void loop()
{
for(pos = 0; pos <= 180; pos++) // goes from 0 degrees to 180 degrees
{ // in steps of 1 degree
myservo.write(pos); // tell servo to go to position in variable 'pos'
delay(15); // waits 15ms for the servo to reach the position
}
}
Right after your for loop put:
while(1);
Before the closing bracket of the loop()
This will stop the program at that point and not keep running your for loop which declares pos = 0 each time.
I see that this question was a bit unpresice.
But I found out that there are one other way of controling a servo, and that is by using writeMicroseconds instead of myservo.write(90).
myservo.writeMicroseconds(1500); //
http://arduino.cc/en/Reference/ServoWriteMicroseconds
I'm trying to code an Arduino avoidance robot as a learning project. When I run the following code only one motor (the left one) works. If I comment out the if statement that uses the checkDistance() function and just loop the forward() function both motors work fine. I'm using an Adafruit Motorshield v1.2, and I believe this is the motor: Link. I've tried powering directly through USB, and also through external power supply (4 x AAs), and have the same issue. Any pointers would be appreciated. Thank you!
#include <AFMotor.h>
#define trigPin 3
#define echoPin 2
AF_DCMotor left_motor(2, MOTOR12_64KHZ); // create motor #1, 64KHz pwm
AF_DCMotor right_motor(1, MOTOR12_64KHZ); // motor #2\
int maxDistance = 30;
//int minDistance = 0;
void setup() {
Serial.begin(9600); // set up Serial library at 9600 bps
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
left_motor.setSpeed(255);
right_motor.setSpeed(255);
}
void forward(int delayTime) {
left_motor.run(FORWARD);
right_motor.run(FORWARD);
delay(delayTime);
}
void backward(int delayTime) {
left_motor.run(BACKWARD);
right_motor.run(BACKWARD);
delay(delayTime);
}
void stop(int delayTime) {
left_motor.run(RELEASE);
right_motor.run(RELEASE);
delay(delayTime);
}
void right(int delayTime) {
left_motor.run(FORWARD);
right_motor.run(BACKWARD);
delay(delayTime);
}
void left(int delayTime) {
left_motor.run(BACKWARD);
right_motor.run(FORWARD);
delay(delayTime);
}
int checkDistance(){
long duration, distance;
/* The following trigPin/echoPin cycle is used to determine the
distance of the nearest object by bouncing soundwaves off of it. */
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
//Calculate the distance (in cm) based on the speed of sound.
distance = duration/59.1;
return distance;
}
void loop() {
int currentDistance = checkDistance();
Serial.print(currentDistance);
if (currentDistance >= maxDistance){
Serial.println(" cm. No immediate obstacles detected. Moving forward.");
forward(2000);
stop(1000);
}
else {
Serial.println(" cm. Obstacle detected. Changing direction.");
right(1500);
stop(1000);
}
}
If I were trying to debug this, I would first test each of the motor functions without any logic check from the sensor. (e.g. do both wheels turn and in the correct direction when left, right, backward, etc are called just from loop()). That will give confidence that it is not a wiring or other hardware problem. If they don't work then sorting that out give you a place to start.
If they do work, then it must be the values with the sensor, right? How did you determine the maxDistancevalue? If it is too high then this line:
if (currentDistance >= maxDistance){
may never evaluate to true. You have some log statements in there so you have some sense of the value of currentDistance. Does it seem to be reflecting accurate values when you place objects at varying distances from the sensor?
Anyway... some thoughts.