Thanks for your reply.
All i want is code really as i have an idea of what else i need but have no idea of code.
I am binning the wireless idea as do not really need it.
What i need to do is have an Arduino as the EMF meter, sticking a sd data logger on top and have it record continuously as it will only be used for two hours at a time and have a bargraph run through a LM3916N-1 driver.
This is the code i was going to use for the EMF meter.
#define sample 300 //this is how many samples the device takes per reading
//more information for #define http://arduino.cc/en/Reference/Define
int inPin = 5; //analog 5
float val; //where to store info from analog 5
int pin11 = 11; //output of red led
int array1[sample]; //creates an array with number of elements equal to "sample"
//more information about arrays http://arduino.cc/en/Reference/Array
unsigned long averaging; //the program uses this variable to store the sum of each array it makes
void setup() {
Serial.begin(9600);
}
void loop() {
for(int i = 0; i < sample; i++){ //this code tells the program to fill each element in the array we made with
array1 = analogRead(inPin); //information from the antenna wire coming out of the Arduino
averaging += array1; //more information about for loops http://arduino.cc/en/Reference/For
} //the averaging line is simply saying: add averaging to whatever is in array position i
//averaging += array is the same as averaging = averaging + array
//for more information about += http://arduino.cc/en/Reference/IncrementCompound
val = averaging / sample; //here the program takes the sum of all numbers in array1, and divides by the number of elements "sample"
val = constrain(val, 0, 100); //this constrains the variable value to between two numbers 0 and 100
val = map(val, 0, 100, 0, 255); //for more information about constrain http://arduino.cc/en/Reference/Constrain
analogWrite(pin11, val); //the map statement tells the program to map out 0-100 to 0-255, 255 is
//the threashold of analogWrite for more information about map http://arduino.cc/en/Reference/Map
averaging = 0; //this line of code sets averaging back to zero so it can be used again
}