Vertical Scrolling, don't know where to start Moderators: adafruit_support_bill, adafruit

[bridge2nowhere]

I want to vertically scroll half the screen (on an Sharp Memory Display LCD). The text is stored in a char* which is variable length, I just gave a sample of what we're working with. I have no idea where to start with this, is there a good way to count "\n" and start in the middle of the string?

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#include <Wire.h>
#include <Adafruit_GFX.h>
#include <RotaryEncoder.h>
#include <Adafruit_SharpMem.h>
#include <SPI.h>
//#include <StreamUtils.h>
#include <Fonts/FreeSansBold12pt7b.h>


#define ENCODER_BUTT 6 //sw
#define ENCODER_1 5 //clk
#define ENCODER_2 9 //dt

#define SHARP_SCK  13
#define SHARP_MOSI 12
#define SHARP_SS   11

#define BLACK 0
#define WHITE 1


RotaryEncoder encoder(ENCODER_1, ENCODER_2);
Adafruit_SharpMem display(SHARP_SCK, SHARP_MOSI, SHARP_SS, 400, 240);



const PROGMEM char* mending[220]= {"This spell repairs a single break\nor tear in an object. As long as the\nbreak or tear is no larger than 1\nfoot in any dimension. This spell\ncan physically repair a magic item\nor construct, but can't restore\nmagic."};

void setup() {

  pinMode(ENCODER_BUTT, INPUT_PULLUP);
  display.begin();
  display.clearDisplay();
  display.refresh();
  delay(2000);
}

void loop() {
  display.setFont(&FreeSansBold12pt7b);
  display.setRotation(2);
  display.setCursor(0,12);
  display.setTextColor(BLACK);
 
  //check encoder
  static int pos = 0;
  encoder.tick();
  int newPos = encoder.getPosition();



  //keep this part static
  display.println("line 1");
  display.println("line 2");
  display.println("line 3");
  //scroll this part using an encoder
  display.println(*mending);
  display.refresh();
}