Asservissement en température numérique d'une cavité ultra-stable au LPL pour le Strontium

Transcription

1 Asservissement en température numérique d'une cavité ultra-stable au LPL pour le Strontium condition de stabilité +/- 10mK Résultas obtenus : 1mk sur la journée Compte tenu des constantes de temps d'intégration nous avons opté pour un lock numérique avec un uc 16 bits. ADC et DAC 12 bits MSP430F169 16bits Texas instruments, and IAR Workbench for MSP430 or Code composer studio for MSP430 Cahier des charges: La précision du lock en température devrait être de l'ordre de 10 mk, pour assurer une stabilité en fréquence du laser de l'ordre de quelques khz. L'élément chauffant a une résistance de 6 Ohm. Un courant de l'ordre de 0.6 A devrait fournir la puissance pour nous amener au point de fonctionnement vers 27 C. Élément de mesure : thermistor MC65F103B Alimentation DC maison linéaire et ajustable pour la partie chauffage. Ci-joint le code C du projet: gestion affiche LCD + calcul température + fonction standby + contrôle de la consigne de température + lock + timer + déclaration des variables + déclaration prototypes + fichier init système (ADC-DAC TIMER- PORT IN OUT) Carte PCB générique avec zone de prototypage pas 2.54mm.

2 Programme principal: void init_sys(void); void tempo_loop(long loop_number); // MSP430 Initialisation routine // wait void write_dac12_0(int out_data); // write DAC12_0 routine void write_dac12_1(unsigned short out_data); // write DAC12_1 routine int read_adc12(int chanel); // read routine on ADC12 char lock(); void standby(); // init state of state machine unsigned short racine(unsigned long valin); int Lcd_Cmd(int portp4); int lcd_display(char *disp); int lcd_display2(char *disp2); int lcd_print(char *s);

3 int Lcd_Clear(); void Lcd_Init(void); int load_lcd_consigne(void); int calcul_resistor_thermistance(void); void visu_etat_lock(void); int consigne=2048; static unsigned int DAC0_out; static unsigned int DAC1_out; static int ADC_in; static int ADC_in_2; static float ADC_in_2_convert_in_volt; static long error_signal; static long accu_out; static long prop; static unsigned long valin; static unsigned short valout; static long control; static char next_state = 0; static char state = 0; static char s[20]; static char t[20]; static double RTH; static double Temperature_in_degre;

4 static double calcul_ln; char i = 0; char j = 0; void main(void) init_sys(); // Initialise the MSP430 Lcd_Init(); tempo_loop(10); Lcd_Clear(); tempo_loop(10); Lcd_Cmd(0x80); lcd_display("welcome to"); Lcd_Cmd(0xc0); lcd_display("cnrs-lpl-ig-up13"); tempo_loop(10); Lcd_Clear(); tempo_loop(10); Lcd_Cmd(0x84); lcd_display("atelier"); Lcd_Cmd(0xc2); lcd_display("electronique"); tempo_loop(10); Lcd_Clear();

5 tempo_loop(10); sprintf(t,"t in Deg= %.3f",Temperature_in_degre); Lcd_Cmd(0x80); lcd_display(t); copy_ram_to_consigne(); Lcd_Cmd(0xc0); sprintf(s,"consigne= %d",consigne); lcd_display(s); standby(); _BIS_SR(LPM0_bits + GIE); // Enter LPM0 w/ interrupt Gestion de l'affichage : //Table 1: Character LCD pins with 1 Controller //**********************************************// //1 VSS Power supply (GND) //2 VCC Power supply (+5V) //3 VEE Contrast adjust //4 RS 0 = Instruction input //1 = Data input //5 R/W 0 = Write to LCD module

6 //1 = Read from LCD module //6 EN Enable signal //7 D0 Data bus line 0 (LSB) //8 D1 Data bus line 1 //9 D2 Data bus line 2 //10 D3 Data bus line 3 //11 D4 Data bus line 4 //12 D5 Data bus line 5 //13 D6 Data bus line 6 //14 D7 Data bus line 7 (MSB) int Lcd_Port(int portp4) P4OUT = portp4; return 0; // Function for sending command to LCD int Lcd_Cmd(int portp4) //RS = 0x00; // => RS = 0 P1OUT &= ~BIT7; /* Pin P1.6 = 0 */ Lcd_Port(portP4); //E = 0x40; // Enable = 1

7 P1OUT = BIT6; /* Pin P1.7 = 1 */ tempo_loop(1000); //E = 0x00; // Enable = 0 P1OUT &= ~BIT6; /* Pin P1.7 = 0 */ return 0; // Function for sending data to LCD int Lcd_data(int portp4) Lcd_Port(portP4); //RS = 0x80; // RS = 1 P1OUT = BIT7; /* Pin P1.6 = 1 */ //E = 0x40; //Enable = 1 P1OUT = BIT6; /* Pin P1.7 = 1 */ tempo_loop(1000); //E = 0x00; // Enable = 0 P1OUT &= ~BIT6; /* Pin P1.7 = 0 */ return 0; int Lcd_Clear() Lcd_Cmd(0);

8 Lcd_Cmd(1); return 0; void Lcd_display_off() Lcd_Cmd(0); Lcd_Cmd(0x0C); void Lcd_Shift_Right() Lcd_Cmd(0x01); Lcd_Cmd(0x18); void Lcd_Shift_Left() Lcd_Cmd(0x01); Lcd_Cmd(0x1C); // Function for initializing LCD void Lcd_Init() Lcd_Cmd(0x38); //Function set: 2 Line, 8-bit, 5x7 dots

9 Lcd_Cmd(0x0c); Lcd_Cmd(0x01); Lcd_Cmd(0x06); //Clear LCD //Entry mode, auto increment with no shift Lcd_Cmd(0x83); // DDRAM addresses 0x80..0x8F + 0xC0..0xCF are used. // Function for sending string to LCD int lcd_display(char *disp) int x=0; while(disp[x]!=0) Lcd_data(disp[x]); x++; return 0; Calcul de la température + affichage int calcul_resistor_thermistance(void) WDTCTL = WDTPW + WDTHOLD; // stop Watch Dog Timer ADC_in_2_convert_in_volt = (ADC_in_2*2.498)/4096; RTH = (ADC_in_2_convert_in_volt*9100)/( ADC_in_2_convert_in_volt); float K = ; // T(25 C)

10 calcul_ln = log((rth/10000)); //log népérien Temperature_in_degre = 1/(calcul_ln/ /K) ; en degrès C //température sprintf(t,"t in Deg= %.3f",Temperature_in_degre); Lcd_Cmd(0x80); lcd_display(t); return 0; fonction standby void standby() WDTCTL = WDTPW + WDTHOLD; DAC0_out= consigne; DAC1_out= 0; // stop WatchDog // init DAC0 // init DAC1 accu_out= 0; P2OUT &= ~BIT1; /* Pin P2.1 = 0 */ P2OUT &= ~BIT2; /* Pin P2.2 = 0 */ P2OUT &= ~BIT3; /* Pin P2.3 = 0 */ P2OUT &= ~BIT4; /* Pin P2.4 = 0 */ P2OUT &= ~BIT5; /* Pin P2.5 = 0 */

11 fonction lock: char lock() error_signal = (ADC_in - consigne); // error_signal => int (16 bits) ( to 32767) prop = error_signal << 21; control = prop + accu_out ; // + (accu_out >> 8); visu_etat_lock(); if(p1in & 0x20) if (accu_out >= accu_out <= ) accu_out = accu_out; else accu_out = (error_signal << 7) + accu_out; if(control < 0) valin = 0; else valin = (control << 1);

12 valout = racine(valin); DAC1_out = valout >> 4; return 0; unsigned short racine(unsigned long valin) //on linéarise la réponse de la thermistance unsigned short valout=0; unsigned long diff=0l; for(int i=0; i<16; i++) diff <<= 2; valout <<=1; diff = valin >> 30; valin <<=2; if(diff > 2*valOut) return valout; diff -= (2*valOut)+1; valout++;

13 fonction timer pour échantillonnage #pragma vector = TIMERB0_VECTOR // timer pour échantillonner à 0.1s interrupt void Timer_B (void) WDTCTL = WDTPW + WDTCNTCL; write_dac12_1(dac1_out); DAC12_1 write_dac12_0(dac0_out); DAC12_0 ADC_in = read_adc12(inch_3); ADC_in_2 = read_adc12(inch_4); // clear and start WatchDog // write DAC1_out to // write DAC0_out to // read signal erreur // read tension thermistor calcul_resistor_thermistance(); if((p2in & 0x01)==0x01) consigne + //P2.0 modification de la valeur de if(p3in & 0x01) consigne = consigne + 10; //handle P1.7 switch if (P3IN & 0x02) consigne = consigne + 100; if(( P3IN & BIT0 ) == 0 && ( P3IN & BIT1 ) == 0 ) consigne = consigne + 1; P1IFG &= ~BIT1;

14 if((p1in & 0x01)==0x01) //P1.0 modification de la valeur de consigne - if(p3in & 0x01) consigne = consigne - 10; //handle P1.7 switch if (P3IN & 0x02) consigne = consigne - 100; if(( P3IN & BIT0 ) == 0 && ( P3IN & BIT1 ) == 0 ) consigne = consigne - 1; P1IFG &= ~BIT0; chargement_consigne(); DAC0_out = consigne; Lcd_Cmd(0xc0); sprintf(s,"consigne= %d",consigne); lcd_display(s); state = next_state; if(p1in & 0x10) // P1.4 mode standby ou lock state=0; else state=1;

15 switch (state) case 0:standby();break; case 1:lock();break; fonction init system and init ports void init_sys(void) P1SEL = 0x00; P2SEL = 0x00; P3SEL = 0x00; P4SEL = 0x00; P5SEL = 0x1B; P5.0 P6SEL = 0x18; Enable A/D channel A3 channel A4 // P1 I/O select // P2 I/O select // P3 I/O select // P4 I/O select // P5.1,3 SPI option select CS // P6.5 ADC_3 options select P1DIR = 0xC0; // P1 inputs direction P1.6 P1.7 outputs P2DIR = 0xFE; // P2 input direction P2.0 input P3DIR = 0xFC; // P3 output direction P3.0 P3.1 inputs P4DIR = 0xFF; // P4 output direction

16 P5DIR = 0xFF; P6DIR = 0xF7; //ADC12CTL0 = REF2_5V + REFON; ADC12CTL0 = SHT0_4 + ADC12ON; ADC12 ADC12CTL1 = SHP + ADC12SSEL_3; clock //ADC12MCTL0 = SREF_1; ADC12MCTL0 = SREF_2; // P5 output direction // P6.3 input/other output // Internal 2.5V ref on // Set sampling time, turn on // Use sampling timer & SMCLK // Use Internal 2.5V for ADC // Vr+ = VeREF+ (external) //DAC12_0CTL = DAC12IR + DAC12AMP_2 + DAC12RES; // 8bits, internal ref gain 1 (DAC_0 select with DAC12AMP_2) //DAC12_1CTL = DAC12IR + DAC12AMP_2 + DAC12RES; // 8bits, internal ref gain 1 (DAC_1 select with DAC12AMP_2) DAC12_0CTL = DAC12IR + DAC12SREF_3 + DAC12AMP_7 + DAC12ENC; //Ref = Veref+, Full-Speed, Enable Conv. DAC12_1CTL = DAC12IR + DAC12SREF_3 + DAC12AMP_7 + DAC12ENC; //Ref = Veref+, Full-Speed, Enable Conv. // DCO frequency ~200 khz DCOCTL &= ~(DCO1 + DCO0); BCSCTL1 &= ~RSEL2; BCSCTL1 = RSEL1; // + ~RSEL0; // timer B TBCCTL0 = CCIE; TBCTL = TASSEL_2 + MC_1 + ID_3; mode // CCR0 interrupt enabled // clk = SMCLK/8 (=DCO/8), Up //TBCCR0 = 2500; // timer count at 1/2500 clk : 0,1s TBCCR0 = 250;

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