/* thermo-manipulator_NTC_ino */
/* --- Temperature calculation --- */
float temperatureNTC( unsigned int ADvalue );
/* --- serial shift 3+4 digit seven-segment display --- */
#define SDI_PIN 4
#define SCLK_PIN 3
#define LOAD_PIN 2
#define DIGITS 7
unsigned char sevseg_array[ DIGITS ];
void sevseg_temperature(unsigned char *, unsigned int);
void sevseg_setChange(unsigned char *, signed int);
void ShiftOut_array(unsigned char *, unsigned char length);
/* --- 7-segment display lookup table --- */
const unsigned char NUMBERS[] = {
// "0123465789 -" for active Low display
0x03, // 0000 0011 "0"
0x9F, // 1001 1111 "1"
0x25, // 0010 0101 "2"
0x0D, // 0000 1101 "3"
0x99, // 1001 1001 "4"
0x49, // 0100 1001 "5"
0x41, // 0100 0001 "6"
0x1F, // 0001 1111 "7"
0x01, // 0000 0001 "8"
0x19, // 0001 1001 "9"
0xFF, // 1111 1111 "Blank"
0xFD // 1111 1101 "Minus"
};
/* --- Up/Dwn buttons --- */
void init_updwn( void);
float Change = 0.0;
signed int svalue = 0;
/* --- PWM output --- */
void init_PWM( void );
// PB1, DDRB, OC1A, (D09)
#define MAX_PWM_VALUE 1023 // resolution 10 bit pwm (16 bit max)
void setup() {
Serial.begin(9600);
pinMode(LOAD_PIN, OUTPUT);
pinMode(SDI_PIN, OUTPUT);
pinMode(SCLK_PIN, OUTPUT);
init_updwn( );
init_PWM( );
sevseg_setChange( sevseg_array, 0 );
delay(500);
}
void loop() {
ShiftOut_array( sevseg_array, DIGITS );
unsigned int ADvalueFWD = analogRead(A0);
unsigned int ADvalueRET = analogRead(A1);
float celsiusFWD, celsiusRET;
float k, m;
float GradientDecrease, GradientIncrease, Offset, Vset, PWM_float;
float t;
unsigned int pwm, uvalue;
celsiusFWD = temperatureNTC( ADvalueFWD );
celsiusRET = temperatureNTC( ADvalueRET );
Serial.print("FWD Temperature: ");
Serial.print(celsiusFWD);
Serial.print(" ℃");
Serial.print(" (REW Temperature: ");
Serial.print(celsiusRET);
Serial.println(" ℃ )");
// present FWD thermometer temperature value
t = celsiusFWD;
t *= 10.0;
t += 0.5; // round
uvalue = (unsigned int) t; // keep integer part
sevseg_temperature( sevseg_array, uvalue );
// GradientIncrease
k = (0.6-1.013)/(76.8-24.6);
m=1.013-k*24.6;
GradientIncrease= k*celsiusFWD + m;
// GradientDecrease
k=(-0.68 - -0.875)/(76.8-24.6);
m=-0.875-k*24.6;
GradientDecrease= -(k*celsiusFWD + m);
// Offset
k = (0.308-0.255)/(76.8-24.6);
m = 0.255-k*24.6;
Offset = k*celsiusFWD + m;
if(Change < 0) Vset=Offset+Change*GradientDecrease;
else Vset=Offset+Change*GradientIncrease;
Serial.print("Change: ");
Serial.print(Change);
Serial.print(" ℃");
Serial.print(" Vset: ");
Serial.print(Vset);
Serial.println(" V");
// PWM 10 bit
k=1024.0/4.48;
m=1023.0-k*2.24;
PWM_float=k*Vset+m;
pwm =(int) PWM_float;
if( pwm > 1023 ) pwm = 1023;
OCR1A = pwm & 0x03FF; // Set a 10 bit PWM value
Serial.print("PWM value: ");
Serial.print( pwm );
Serial.println( );
Serial.println( );
// readUp Button
if( ( PINC & ( 1 << PC3 )) == 0 )
{
svalue += 5;
if( svalue > 250 ) svalue = 250;
sevseg_setChange( sevseg_array, svalue );
ShiftOut_array( sevseg_array, DIGITS );
Change = (float) svalue;
Change /= 100.0;
while( ( PINC & ( 1 << PC3 )) == 0 ) /* do nothing */ ; // wait for button release
}
// read Dwn Button
if( ( PINC & ( 1 << PC2 )) == 0 )
{
svalue -= 5;
if( svalue < -250 ) svalue = -250;
sevseg_setChange( sevseg_array, svalue );
ShiftOut_array( sevseg_array, DIGITS );
Change = (float) svalue;
Change /= 100.0;
while( ( PINC & ( 1 << PC2 )) == 0 ) /* do nothing */ ; // wait for button release
}
delay(500);
}
/* *********************************** */
/* FUNCTIONS */
/* *********************************** */
/* ------------------------ */
/* Temperature conversion */
/* ------------------------ */
float temperatureNTC( unsigned int ADvalue ) // using Steinhart-Hart
{
const float BETA = 3950;
// should match the Beta Coefficient of the thermistor
float celsius = 1 / (log(1 / (1023. / ADvalue - 1)) / BETA + 1.0 / 298.15) - 273.15;
if(celsius < 0) celsius = 0;
return celsius;
}
/* ----------------------------- */
/* Shiftregister 7-seg display */
/* ----------------------------- */
void sevseg_temperature(unsigned char sevseg_array[], unsigned int temperature)
{
unsigned char data;
unsigned int temp;
temp = temperature % 10; // x--
data = (unsigned char) temp;
data = NUMBERS[data];
// data &= 0xFE; // insert decimal point x.--
sevseg_array[4] = data;
temperature = temperature / 10;
temp = temperature % 10; // -x-
data = (unsigned char) temp;
data = NUMBERS[data];
data &= 0xFE; // insert decimal point -x.-
sevseg_array[5] = data;
temperature = temperature / 10;
temp = temperature % 10; // --x
data = (unsigned char) temp;
data = NUMBERS[data];
// data &= 0xFE; // insert decimal point --x.
sevseg_array[6] = data;
}
void sevseg_setChange(unsigned char sevseg_array[], signed int number)
{ /* sign, 3 digits, 2 decimals */
unsigned char data;
unsigned int num;
unsigned char sign = 0;
if(number <0 ){number=-number; sign =1; }
num = number % 10;
data = (unsigned char) num;
data = NUMBERS[data];
sevseg_array[0] = data;
number = number / 10;
num = number % 10;
data = (unsigned char) num;
data = NUMBERS[data];
// data &= 0xFE; // insert decimal point
sevseg_array[1] = data;
number = number / 10;
num = number % 10;
data = (unsigned char) num;
data = NUMBERS[data];
data &= 0xFE; // insert decimal point - 2 decimal
sevseg_array[2] = data;
// number = number / 10;
// num = number % 10;
// data = (unsigned char) num;
// data = NUMBERS[data];
if(sign == 0) data = NUMBERS[10]; // minus sign
else data = NUMBERS[11]; // blank
sevseg_array[3] = data;
}
void ShiftOut_array(unsigned char sevseg_array[], unsigned char length)
{
digitalWrite(LOAD_PIN,LOW);
for (int i=0; i< length; i++){
shiftOut(SDI_PIN, SCLK_PIN, LSBFIRST , sevseg_array[i]);
}
digitalWrite(LOAD_PIN,HIGH);
}
/* ------------------------ */
/* Set Change Up Down */
/* ------------------------ */
void init_updwn( void)
{
DDRC &= ~( 1 << PC3 ); // PC3 '0' is input, Up
PORTC |= ( 1 << PC3 ); // activate internal pullup
DDRC &= ~( 1 << PC2 ); // PC2 '0' is input, Dwn
PORTC |= ( 1 << PC2 ); // activate internal pullup
}
/* ------------------------ */
/* PWM output */
/* ------------------------ */
// Setup timer for 16 bit PWM
void init_PWM( void ) {
TCCR1A = 1 << WGM11 | 1 << COM1A1; // set on top, clear OC on compare match
// TCCR1B = 1 << CS10 | 1 << WGM12 | 1 << WGM13; // clk/1, mode 14 fast PWM
TCCR1B = 1 << CS11 | 1 << WGM12 | 1 << WGM13; // clk/8, mode 14 fast PWM
ICR1 = MAX_PWM_VALUE;
DDRB |= ( 1 << PB1 ); // "1" PWM-pin direction is output
}
/* *********************************** */
/* HARDWARE */
/* *********************************** */
/* Chip ATMega328 Arduino Uno R3 stackable header
_______
Digital: _____/ \__ Analog:
______________ ______________ txd ->-|D00 >RXD A5|-
| \/ | rxd -<-|D01 <TXD A4|-
Res---|01 PC6/RES' ATM328 SCL/PC5 28|-(A5)- SEG7_Load -<-|D02 A3|-<- UP
txd ->-(D00)-|02 PD0/RXD SDA/PC4 27|-(A4)- SEG7_SCLK -<-|D03~ A2|-<- DWN
rxd -<-(D01)-|03 PD1/TXD PC3 26|-(A3)- UP SEG7_SDI -<-|D04 A1|-<-NTC_RET_OUT
Load-(D02)-|04 PD2/INT0 PC2 25|-(A2)- DWN -|D05~ A0|-<-NTC_FWD_OUT
SCLK-(D03)-|05 PD3/INT1/PWM PC1 24|-(A1)-<-NTC_REW_OUT -|D06~ | Power:
SDI-(D04)-|06 PD4 PC0 23|-(A0)-<-NTC_FWD_OUT -|D07 Vin|-
+5V ---|07 VCC GND 22|--- Gnd | GND|--- GND
Gnd ---|08 GND AREF 21|--- Vin -|D08 GND|-
Xtal |X|--|09 PB6/OSC1 AVCC 20|--- +5V -|D09~ +5V|--- +5V
16MHz |X|--|10 PB7/OSC2 SCK/PB5 19|-(D13)- -|D10~ +3.3V|-
-(D05)-|11 PD5/PWM MISO/PB4 18|-(D12)- -|D11~ Res|-
-(D06)-|12 PD6/PWM PWM/MOSI/PB3 17|-(D11)- -|D12 IOREF|-
-(D07)-|13 PD7 PWM/SS'/PB2 16|-(D10)- -|D13 LED --- |
-(D08)-|14 PB0 PWM/PB1 15|- -|GND |
|______________________________| -|AREF |
-|SCL |
-|SDA |
|________________|
*/
/*
74HC595 Shiftregister for 3 digit 7-segment display
______________________________________
| SEG7 Active low '0' LED on |
+5V ---|Vcc /-a-\ Vcc|---
GND ---|Gnd f b Gnd|---
D04 ->-|SDI |-g-| a.b.c.d.e.f.g.dp SDO|---
D03 ->-|SCLK e c lsb first SCLK|---
D02 ->-|Load \-d-/ dp Load|---
|______________________________________|
*/
/*
________________
| NTC Thermistor |
NTC_OUT -| NTC 10k |
VCC -| R 10k |
GND -| |
|________________|
*/