What Am I Doing Wrong?

Using Arduino Programming Questions
#1

Hey All,

I am having right issues getting a vertical scrolling LCD working.

The code below checks a 18 core cable for continuity, then reports back on the LCD with each cores results and whether the cable passed or not.

I am struggling with how to print to the lcd the pin numbers (lcdPrint(o):wink:

I do get the error:

soca_tester:85: error: converting to ‘String’ from initializer list would use explicit constructor ‘String::String(unsigned char, unsigned char)’

lcdPrint(o);

But i cannot find anything online that makes sense to me

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);
String Line1;
String Line2;
uint8_t outPins[] = {47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30};             // Output pins
uint8_t inpPins[] = {29, 28, 27, 26, 25, 24, 23, 22, 51, 50, 19, 18, 17, 16, 15, 14, 48, 49};         // Input pins

// LCD SCROLLING SETUP //
void lcdPrint(String lcdText) {
    lcd.clear();
    Line1 = Line2;
    lcd.setCursor(0, 0);
    lcd.print(Line1);
    Line2 = lcdText;
    Line2.replace("\r\n", "");
    lcd.setCursor(0, 1);
    lcd.print(Line2);
    Line1 = "";
    lcdText = "";
}
// LCD SCROLLING SETUP //

void setup(){
  Serial.begin(115200);
  
  lcd.begin();                      // initialize the lcd 
  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(1,0);
  lcd.print("Socapex Tester");
  delay(3000);
  
  
  for (uint8_t i = 0; i < sizeof(outPins); i++){  // Setup output pins
    pinMode(outPins[i],OUTPUT);
    digitalWrite(i,LOW);
  }
  for (uint8_t i = 0; i < sizeof(inpPins); i++){  // Setup input pins
    pinMode(inpPins[i],INPUT);                    // Turn off internap pullup resistor
  }
  Serial.println("Begin...");
  if (testCable() == true)
  {
  lcdPrint("** Passed **");
  Serial.println("** Passed **");
  }
  else 
  {
  Serial.println("** Failed **");
  lcdPrint("** Failed **");
  //lcd.clear();
  //lcd.setCursor(1,0);
  //lcd.print("Failed");
  }
}

void loop(){
}

bool testCable(){
  bool testResult = true;                         // Assume cable is good
  uint8_t count = 0;                              // Count of correct connections
  
  if (sizeof(outPins) != sizeof(inpPins)) {       // Array sizes match?
    Serial.println(F("ERROR: Array Sizes Do Not Match."));
    return false;                                 // Exit now
  }
  
  for (uint8_t o = 0;  o < sizeof(outPins); o++){ // Loop though output pins
    Serial.print("Pin \t");
    Serial.print(o);
    //Serial.print("[");
    //Serial.print(outPins[o]);
    //Serial.print("]\t");
    
    digitalWrite(outPins[o],HIGH);                // Set pin high
    if (digitalRead(inpPins[o]) == HIGH){         // Is correct pin connected?
      count++;                                    // Increment count
      Serial.print("->");                          // Display it as first pin
      Serial.print(o);                            // Display it as first pin
      //Serial.print("[");
      //Serial.print(inpPins[o]);
      //Serial.print("]");
      
      lcdPrint(o);
      
      delay(500);
      
    }
    
    for (uint8_t i = 0; i < sizeof(inpPins); i++){// Scan input pins
      if (digitalRead(inpPins[i]) == HIGH){       // If pin is high must be connected to output
        if (o != i){                              // If array numbers don't match then must be error
          Serial.print(" X ");
          Serial.print(i);
          //Serial.print("[");
          //Serial.print(inpPins[i]);
          //Serial.print("]");
          testResult = false;                     // Bad wire
        }
      }
    }
    digitalWrite(outPins[o],LOW);                 // Set output back to low
    Serial.println();                             // New line ready for next pin
  }
  
  if (count != sizeof(outPins)){                  // Have we had the correct number of correct pins?
    testResult = false;                           // If not then must be error
  }
  return testResult;
}
#2

This function takes a String parameter

void lcdPrint(String lcdText) {

you pass it a uint8_t

  for (uint8_t o = 0;  o < sizeof(outPins); o++){ // Loop though output pins
...     
      lcdPrint(o);

By the way, single character variable names in such a large code block is considered very bad form.

#3

Does lcd.print accept unsigned char (uint8_t) or does it assume signed, ie. int8_t ?
The documentation only mentions string, char, byte, int and long.

#4 
void lcdPrint(String lcdText)

The lcdPrint function takes a String as its parameter

     lcdPrint(o);

You are trying to print an integer
Start by converting o to a String before printing it

Better still, don't use Strings at all

#5