hi, im making a project with POV , what im trying to do is to show trough the LEDs (POV) what a NTC temperature sensor is reading.
The problem is how can i put an integer value(int) to a char. Thanks.
PD. Each program works perfectly independent.
// defining the alphabet
#include "alphabet.h"
// define the Arduino LED pins in use
const int LEDpins[] = {1,2,3,4,5,6,7};
// number of LEDs character height and width
int charHeight = sizeof(LEDpins); //sizeof its value from arduino code
int charWidth = 5;
//Temperature
const float voltage = 5.00;
const float B = 4100;
const float unodivr = 93.0;
const float resistor = 105000; //Resistor
int sensorPin = A0; // select the input pin for the potentiometer
int sensorValue = 0;
void setup()
{
pinMode(1, OUTPUT);
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
Serial.begin(9600);
}
void loop()
{
// Part 1: Read the analog port 0 and convert the value to volts.
sensorValue = analogRead(sensorPin);//read analog 0
float v2 = (voltage*float(sensorValue))/1024.0f; // calculate volts in an awesome world
// Part 2: Calculate the resistance with the volt value trough the voltage divider ecuation
float r1a = (voltage*float(resistor))/v2;
float r1 =r1a - resistor;
//Part 3: Calculate the temperature based on the Steinhart-Hart equation based on the B value equation.
float K = B/log(r1*unodivr);//Temperature in Kelvin
int C=K-273;//Temperature in Celsius
Serial.println(C);
//PRoblem
}
//Function for print the letters
void printLetter(char ch)
{ // make sure the character is within the alphabet bounds (defined by the alphabet.h file)
// if it's not, make it a blank character
if (ch < 32 || ch > 126){ch = 32;}
ch -= 32;// subtract the space character (converts the ASCII number to the font index number)
// step through each byte of the character array
for(int i=0; i<charWidth; i++){byte b = font[ch][i];
// bit shift through the byte and output it to the pin
for(int j=0; j<charHeight; j++){digitalWrite(LEDpins[j], !!(b & (1 << j)));}
// space between columns
delayMicroseconds(3000);
}
//clear the LEDs
digitalWrite(1 , LOW); // set the LED on
digitalWrite(2 , LOW); // set the LED on
digitalWrite(3 , LOW); // set the LED on
digitalWrite(4 , LOW); // set the LED on
digitalWrite(5 , LOW); // set the LED on
digitalWrite(6 , LOW); // set the LED on
digitalWrite(7 , LOW); // set the LED on
// space between letters
delayMicroseconds(100);
// printing every letter of the textString
for (int k=0; k<sizeof(textString); k++){printLetter(textString[k]);}
}
