need help with arduino code

you are not limiting the chenges to the motor speed variable, it is an integer and therefor 16 bits on this platform (0 - 65535) or in this case as it is not an unsigned int -32767 to + 32768

you need a check in the loop along the lines of the following

if (motorspeed < 0 ) motorspeed = 0;

if (motorspeed > 255) motorspeed = 255;

this will cap the value in each direction

as your currently incrementing or decrementing inside the analogue write, then you can put these two statements anywhere in the loop to keep things in check as you have the ++ -- after the variable, it is performed after the variable is used, not before so the checks will still work without going under or over the right values

it would probable be more elegent to manage the actual value outside of the analogue write and perform the checks before writing to the output.

Hope this helps

I would follow Robert Peter Oakes advice and manipulate the 'motorspeed' variable first. Ideally you should only be calling the analogWrite function once.

For Your First Code it isnt too bad.

Just a few small problems on top of those mentioned above:

>You already initialised buttonAState at the beginning of the code, no need to use int buttonAState in the main loop

>You dont say what motor you are controlling [make sure its not too big to be driven off a digital pin]

>Again no circuit diagram, so we dont know if you have external pull down resistors, the input pins are high impendance

Why Pull downs: the input pins are high impedance and will stay at 5v after you stop pressing the button if you dont include some way to drain current, or go high randomly from noise etc [google it for more info]

If you dont want to wire external resistors for the button you can do it like this:

Make a pushbutton without a resistor

This Code should fix the problems: [I have no arduino handy to test it, but it is a simple code and should work if you wire the button as described above]

//*******************************************************************************************************************//

/*

Michael Ratcliffe  mike@michaelratcliffe.com

    This program is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation, either version 3 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program.  If not, see <http://www.gnu.org/licenses/>.

Wireless pin detail:

Remember the Button Is now Connected To Ground #################################

Button   Arduino Digital Pin   Wireless Receiver

A          4                    D3

B          3                    D2

C          2                    D1

D          1                    D0

A: Speed up

B: Slow down

*/

const int Abutton = 8;

const int Bbutton = 9;

const int MotorPin =6;

int motorspeed = 128;

int buttonAState = 0;

int buttonBState = 0;

void setup() {

pinMode(MotorPin, OUTPUT);                // MotorPin

pinMode(Abutton, INPUT_PULLUP);       //A button & turn on pullup resistors

pinMode(Bbutton,INPUT_PULLUP);     //B button &turn on pullup resistors

Serial.begin(9600);

}

void loop() {

                buttonAState = digitalRead (Abutton);

                delay(10);//not needed

                buttonBState = digitalRead (Bbutton);

//********** If Else Because there is no need to do the second request if the first one is satisfied **//

if (buttonAState == LOW){

     motorspeed++;

  }

else if(buttonBState ==LOW){

  motorspeed--;

}

              if((motorspeed)>254);

              motorspeed=254;

              if((motorspeed)<10);

              motorspeed= 10;

analogWrite (MotorPin, motorspeed);

Serial.print("PWM: ");

Serial.println(motorspeed);

delay(100);

};

//*************************************************************************************************************************//

The If Else does impart a behaviour you need to be aware of

If both buttons are pressed at the same time, rather than the net result being no increase or decrease, the loop will now favour increasing till the MAX is reached. If you want the behaviour to be such that both buttons means stay at the current value, simply remove the "else" from the else if.

asside from that, Michaels solution is a good fix for your problem and he also presents several good coding practices

namely

COMMENTING THE CODE

Using well definesd and PRE-INITIALIZED variables

An upfront description and Licence declaration

Use of not often used parameters in defining the functionality of the pins, namely the INPUT_PULLUP which in many cases removes the need for an external pullup resistor on a switch... nice

Make a short video and post it here, that would be awsome

Hi Darren.

Thanks for the feedback. It's nice to hear a success story.

Agreed a Video Would be Good, to see what you are using the arduino for.