Electronics Question (arduino)

Did you buy the ATTINY yet?

Hopefully not, if you did no biggy you're only out a couple of bucks and you'll use it someday.

However if you look on eBay for "Arduino Mini" there's a small micro controller Arduino with much more I/O and is available for about 5-8 bucks U.S. it would be easier to integrate and has all the I/O you'd need in your controller without having to do some high level programming.

It's a cheap Chinese knockoff but it's fully compatable.

Then the basic idea is to program the mini in the loop to monitor the current values of each input and create either a String or if you're comfortable with it a Byte array where you would add each value from each input. Separate the string values with like a carriage return char so you can parse them later easier. Then after you've built the string send it down to the other Arduino in the car serially and parse through the string applying each value to their respective outputs. 

I'd put a delay of 5-10 ms after that before looping again to ensure the Uno is finished before the buffer is hit again with another packet.

Congrats you've just design and hopefully programmed a protocol.

Did you buy the ATTINY yet?

Hopefully not, if you did no biggy you're only out a couple of bucks and you'll use it someday.

However if you look on eBay for "Arduino Mini" there's a small micro controller Arduino with much more I/O and is available for about 5-8 bucks U.S. it would be easier to integrate and has all the I/O you'd need in your controller without having to do some high level programming.

It's a cheap Chinese knockoff but it's fully compatable.

Then the basic idea is to program the mini in the loop to monitor the current values of each input and create either a String or if you're comfortable with it a Byte array where you would add each value from each input. Separate the string values with like a carriage return char so you can parse them later easier. Then after you've built the string send it down to the other Arduino in the car serially and parse through the string applying each value to their respective outputs. 

I'd put a delay of 5-10 ms after that before looping again to ensure the Uno is finished before the buffer is hit again with another packet.

Congrats you've just design and hopefully programmed a protocol.

Totally agree with the Arduino Mini, Good shout.

You can also use the Arduino Nano, with a built-in USB interface.

Thanks Paul, Tim and Douglas.

That sounds like a good idea. I haven't bought the AtTiny yet but i might still get them as they are very useful.

I'll give a shot at programming the protocol and see how it turns out.

Also do you think i should use a Arduino Nano in the remote and in the car to reduce space.

All your help is very much appreciated,

Just another quick question any idea if the 2 servos and motor will work together if all running at same time, as the way i have it now only one servo works at a time and the motor loses considerable speed when a servo is active.

This might just be a programming error which i will check when i start programming the new program but i would like to get your opinion also.

Kind Regards

Ricky

Could be programming, or could be losses on the wire or internal battery resistance.  Try running on a power supply or bigger battery pack to see if the problem goes away.

I will try these, thanks

Post your code.

int switchPin = 4; // switch input

int motor1Pin = 5; // H-bridge leg 1

int motor2Pin = 6; // H-bridge leg 2

int speedPin = 11; // H-bridge enable pin

int ledPin = 13; //LED

int potPin = 0;

int speed = 0;

// set pin numbers:

const int buttonPin = 2;     // the number of the pushbutton pin

int potpin1 = 1;  // analog pin used to connect the potentiometer

int buttonState = 0;         // variable for reading the pushbutton status

int val;    // variable to read the value from the analog pin

#include <Servo.h>

Servo doorservo;  // create servo object to control a servo

Servo steeringservo;  // create servo object to control a servo

void setup() {

// set the switch as an input:

Serial.begin (9600);

pinMode(switchPin, INPUT);

// set all the other pins you're using as outputs:

pinMode(motor1Pin, OUTPUT);

pinMode(motor2Pin, OUTPUT);

pinMode(speedPin, OUTPUT);

pinMode(ledPin, OUTPUT);

// set speedPin high so that motor can turn on:

digitalWrite(speedPin, HIGH);

// blink the LED 3 times. This should happen only once.

// if you see the LED blink three times, it means that the module

// reset itself,. probably because the motor caused a bownout

// or a short.

blink(ledPin, 3, 100);

  // initialize the pushbutton pin as an input:

  pinMode(buttonPin, INPUT);   

  doorservo.attach(10);  // attaches the servo on pin 9 to the servo object

  steeringservo.attach(9);  // attaches the servo on pin 9 to the servo object

}

void loop(){

  // read the state of the pushbutton value:

   buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.

  // if it is, the buttonState is HIGH:

  if (buttonState == HIGH) {    

    doorservo.write(180);                  // sets the servo position according to the scaled value

     delay(10000);                           // waits for the servo to get there

  }

  else {

    // send servo home:

      doorservo.write(5);                  // sets the servo position according to the scaled value

      delay(100);                           // waits for the servo to get there

  }

  val = analogRead(potpin1);            // reads the value of the potentiometer (value between 0 and 1023)

  val = map(val, 0, 1023, 0, 179);     // scale it to use it with the servo (value between 0 and 180)

  steeringservo.write(val);                  // sets the servo position according to the scaled value

  delay(15);                           // waits for the servo to get there

// if the switch is high, motor will turn on one direction:

if (digitalRead(switchPin) >0) {

digitalWrite(motor1Pin, LOW); // set leg 1 of the H-bridge low

digitalWrite(motor2Pin, HIGH); // set leg 2 of the H-bridge high

speed = analogRead(potPin);

speed = 793 + (speed/6);

analogWrite (speedPin, speed);

Serial.println(speed);

delay (50);

}

// if the switch is low, motor will turn in the other direction:

else {

digitalWrite(motor1Pin, HIGH); // set leg 1 of the H-bridge high

digitalWrite(motor2Pin, LOW); // set leg 2 of the H-bridge low

speed = analogRead(potPin);

speed = 793 + (speed/6);

analogWrite (speedPin, speed);

Serial.println(speed);

delay (50);

}

}

/*

blinks an LED - SIGNIFIES RESET AND ARDUINO SHUTDOWN

*/

void blink(int whatPin, int howManyTimes, int milliSecs) {

int i = 0;

for ( i = 0; i < howManyTimes; i++) {

digitalWrite(whatPin, HIGH);

delay(milliSecs/2);

digitalWrite(whatPin, LOW);

delay(milliSecs/2);

}

}

Comment out your Serial.print commands

They're really taxing

Hey.

that makes a big difference with the speed at which everything happens but

it still didn't solve the problem.

Its no biggie tho.

I also noticed that when i press the button to open the door, it will not let any other signal through.

EG: when the door is open, if i change the speed of the motor it will not change until he door (servo) starts to close.

Thanks

I don't understand why you're delaying the program for 10 seconds after you set the Servo for the door to open?

Your comment says to make sure the door gets there.  However the servo itself has small circuitry which will ensure that the servo gets to the position you tell it to go via a digital or analog feedback signal internally.  So you don't need to do this.

Your program is just going to hang there until its done which delays any more execution.  The PWM signal being generated by the Arduino won't change until you re-write a new value into that pin so it's pretty much guaranteed to get there.

Whats the significance of this line:

speed = analogRead(potPin);
speed = 793 + (speed/6);

Why the math on it? Perhaps you can do something else hardware wise like a scaled voltage divider circuit?

Hi Tim.

Thanks very much for the help.

I got rid of all the lines that had the servo delay. This made a huge difference to the running of the servo. They now run much smoother and don't jump around then stopped.

The 10 second delay for the door is because i have one button that opens the door and then 10 sec later it closes automatically.

I am not 100% sure what you mean by a scaled voltage divider.

Do you mean put 4 resistors of different values and then send the voltage to the one i want to use?

Thanks

Ricky