Writing a code from EEPROM to an array of char

Question

On the EEPROM the pincode 1234 is written as bytes. Now I want to read out the pincode and write it to an array of type char and print it on the serial monitor, but I only get this rectangles like in the picture. But if I print it directly to the serial monitor with "Serial.print(EEPROM.read(i));" I get "1234". serial monitor

const byte PINLENGTH = 4;
char pinCode[PINLENGTH+1];

void setup() {
Serial.begin(9600);
Serial.print(pinCode[0]);

for ( int i = 0; i < PINLENGTH; ++i ){
  pinCode[i] = (char) EEPROM.read(i);
  Serial.print(pinCode[i]);
}}


void loop() {

}

Is the "pin code" stored as *characters* or as the numbers raw binary form? — Some programmer dude, Oct 15 '19 at 13:26
And why do you print `pinCode[0]` before you have read into the array? — Some programmer dude, Oct 15 '19 at 13:26

score 0 · Accepted Answer · answered Oct 15 '19 at 13:28

Try this:

const byte PINLENGTH = 4;
char pinCode[PINLENGTH+1];

void setup() {
Serial.begin(9600);

for ( int i = 0; i < PINLENGTH; ++i ){
  pinCode[i] = (char) EEPROM.read(i) + '0';    // <- Note +'0'
  Serial.print(pinCode[i]);
}}

The point here is that the values read from the EEPROM are probably binary, and adding '0' converts them to ASCII.

score 0 · Answer 2 · answered Oct 15 '19 at 14:54

0

byte b1=1;
char c1 = 49;
char c2 = '2';
Serial.print(b1); 
Serial.print(c1); 
Serial. println(c2);

produces the output "112", because print behaves different on different data types.

answered Oct 15 '19 at 14:54

datafiddler

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Writing a code from EEPROM to an array of char

2 Answers2