Need some help with double to const char

I'm playing with the video experimenter shield and I'm trying to display values from A0 pin. (Voltage divider to read voltage of a battery)
I can't seem to make it work.
Can you tell me what I'm doing wrong?
The error message I get is cannot convert 'double' to 'const char*' for argument '2' to 'int sprintf(char*, const char*, ...)'
The error is of course thrown at the sprintf(s, outputValue / 15.270 , millis());

#include <TVout.h>
#include <fontALL.h>

#define W 136
#define H 96

TVout tv;
unsigned char x,y;
unsigned char originx = 5;
unsigned char originy = 80;
unsigned char plotx = originx;
unsigned char ploty = 40;
char s[32];
unsigned int n = 0;
int index = 0;
int messageLen = 32;
/////////////////////vdc in
const int analogInPin = A0;
int sensorValue = 0;

//int sensorValue = 0;        // value read from the pot
int outputValue = 0; 

void setup()  {
  tv.begin(NTSC, W, H);
//  drawGraph();

// Initialize ATMega registers for video overlay capability.
// Must be called after tv.begin().
void initOverlay() {
  TCCR1A = 0;
  // Enable timer1.  ICES0 is set to 0 for falling edge detection on input capture pin.
  TCCR1B = _BV(CS10);

  // Enable input capture interrupt
  TIMSK1 |= _BV(ICIE1);

  // Enable external interrupt INT0 on pin 2 with falling edge.
  EIMSK = _BV(INT0);
  EICRA = _BV(ISC11);

// Required to reset the scan line when the vertical sync occurs
ISR(INT0_vect) {
  display.scanLine = 0;

void loop() {

sensorValue = analogRead(analogInPin);  
outputValue = map(sensorValue, 0, 1023, 0, 255); 
  sprintf(s, outputValue / 15.270 , millis());
  tv.print(0, 0, s);
sprintf(s, "this works", millis());
tv.print(0, 80, s);


Moderator edit: tags corrected.

sprintf doesn't take a numeric value for it's second argument, it takes a string containing formatting flags.


sprintf(buffer, "It has been %d seconds since reset", millis()/1000);
sprintf(s, "this works", millis());

Here all the requirements are ok, but I bet it won't fulfill your secret wishes.

Next problem will be that Arduino cannot sprintf ("%f", myfloat);
That's an often solved problem, you'll solve faster by searching than by asking.