I find if you don't on this form people get upset

ok how the hell do I do that lol

ok I have only altered code in the void setup so the first bit clears the eeprom and then the bit at the end which I presume is right but im guessing not lol writes to the eeprom
when I have got this first bit right I will then alter the bit in the void loop to read the min and max value from the eeprom

what do you think?

#include <Servo.h>
Servo myservo;               // create servo object to control a servo

#include <EEPROM.h>          // EEPROM
int addr = 0;

int potpin      = 0;       // analog pin used to connect the potentiometer
int ch1         = 5;       // PWM input
int val2;                  // variable to read the value from the analog pin
int buttonPin   = 11;      // caliberate button
int sensorValue = 0;       // the sensor value
int sensorMin   = 740;     // minimum sensor value
int sensorMax   = 0;       // maximum sensor value

void setup()
{
  myservo.attach(9);      // attaches the servo on pin 9 to the servo object
  pinMode(ch1,        INPUT);
  pinMode(buttonPin,  INPUT);

  if (digitalRead(buttonPin)==     HIGH)
  {                                                        // ** ...cailable... ** //
    digitalWrite(12, HIGH);
   
      // write a 0 to all 512 bytes of the EEPROM
   for (int i = 0; i < 512; i++)                          // clear the EEPROM
   EEPROM.write(i, 0);
     
    // calibrate during the first five seconds
    while (millis() < 5000) {
      sensorValue = analogRead(potpin);

      // record the maximum sensor value
      if (sensorValue > sensorMax) {
        sensorMax = sensorValue;
      }
      // record the minimum sensor value
      if (sensorValue < sensorMin) {
        sensorMin = sensorValue;
      }
    }
   digitalWrite(12, LOW);
   EEPROM.write(addr, sensorMax);                          // wite max to the EEPROM
   EEPROM.write(addr, sensorMin);                          // wite min th the EEPROM
  }
}

void loop()
{
  sensorValue = analogRead(potpin);                                      // reads the value of the potentiometer (value between 0 and 1023)
  ch1 = pulseIn(5, HIGH, 25000);                                         // Read the pulse width of

  // apply the calibration to the sensor reading
  sensorValue = map(sensorValue, sensorMin, sensorMax, 0, 740);

  // in case the sensor value is outside the range seen during calibration
  sensorValue = constrain(sensorValue, 0, 740);

  val2 = map(ch1, 0, 1000, 0, 20);                                      // scale from 0 to 20 for the zero for the servo
  sensorValue = map(sensorValue, 0, 740, val2, 150);                    // scale it to use it with the servo (value between 0 and 180)
  myservo.write(sensorValue);                                           // sets the servo position according to the scaled value
  delay(5);                                                             // waits for the servo to get there
}

always use values from the eeprom unless the button has been pressed to calibarate which will clear the eeprom then write new values.
that's what I was thinking anyway. please say If I have missed anything.

so can I save the values to the arduino, I presume we have to use the eeprom?

What are "the values" that you want to save to EEPROM?

the max and min values that the calibrate function come up with

cool ok thanks for that

I have looked at the arduino examples but was struggling how to intergrade it in my code/ application

how do we go about writing this

yes that is fine but as I have said is it worth putting some sort of protection after that e.g. the zener diode or something else as the supply is up and down and quite possibly having a few spikes in it which could harm the arduino

that is fine but not if the voltage goes over 5v

all gone a bit quiet lol

ok cool the 12v could veriate from 11-14v so would it be a good idea to put some protection on it like a 5.1v zener diode?

hi there the subject gives it away, I want to read a PWM on my arduino but the PWM is 12v so my question is what is the best way to drop the voltage down to 5 v for the arduino?

as you can see I have added calibrate function what works fine, but when the arduino is powered down it forgets it range so can I save the values to the arduino, I presume we have to use the eeprom? how do we do that?

Code:

#include <Servo.h>

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

int potpin     = 0;        // analog pin used to connect the potentiometer
int potpin2    = 1;        // analog pin used to connect the potentiometer
int val2;                  // variable to read the value from the analog pin
int buttonPin  = 11;       //caliberate button
int sensorValue = 0;       // the sensor value
int sensorMin  = 740;      // minimum sensor value
int sensorMax  = 0;        // maximum sensor value

void setup()
{
  myservo.attach(9);      // attaches the servo on pin 9 to the servo object
  pinMode(buttonPin,  INPUT);

  if (digitalRead(buttonPin)==     HIGH)
  {                                                        // ** ...cailable... ** //
    digitalWrite(12, HIGH);
    // calibrate during the first five seconds
    while (millis() < 5000) {
      sensorValue = analogRead(potpin);

      // record the maximum sensor value
      if (sensorValue > sensorMax) {
        sensorMax = sensorValue;
      }
      // record the minimum sensor value
      if (sensorValue < sensorMin) {
        sensorMin = sensorValue;
      }
    }
    digitalWrite(12, LOW);
  }
}

void loop()
{
  sensorValue = analogRead(potpin);                                      // reads the value of the potentiometer (value between 0 and 1023)
  val2 = analogRead(potpin2);                                            // reads the value of the potentiometer (value between 0 and 1023)

  // apply the calibration to the sensor reading
  sensorValue = map(sensorValue, sensorMin, sensorMax, 0, 740);

  // in case the sensor value is outside the range seen during calibration
  sensorValue = constrain(sensorValue, 0, 740);

  val2 = map(val2, 0, 1023, 0, 20);                                    // scale from 0 to 10 for the zero for the servo
  sensorValue = map(sensorValue, 0, 740, val2, 150);                    // scale it to use it with the servo (value between 0 and 180)
  myservo.write(sensorValue);                                          // sets the servo position according to the scaled value
  delay(15);                                                            // waits for the servo to get there
}

you have used the serial monitor to check the values you get from analog read is my understanding, yes?

yes on the 10k pot 0-1023 nice and smooth but not linea

on the 5k pot it go's 0-740 so I edited the 1023 to 740 what work fine but I still had the dead band so I played with the 0-180 and took it down the 0-150 and now seems to work over the full range