#include #include #fuses HS,WDT,NOPROTECT,PUT // high speed osc, watchdog on, no code protect, power up timer on //#use delay (clock=4000000) // 4MHz clock #use delay (clock=16000000) // 16MHz clock #use RS232(baud=19200,xmit=PIN_C6,rcv=PIN_C7) // 19.2K baud (LCD default) #use FAST_IO(A) // I/O dir doesn't change when #use FAST_IO(B) // reading and writing to ports #use FAST_IO(C) #use FAST_IO(D) // global variables int8 h_cnt; // loop counter for heaters 0-3 int8 h_io[10]; // heater output bits (0-3) int8 c_cnt; // counter for each time the outputs change unsigned int16 pwm[4]; // heaters are on for this long (0-2^16) TIMER1 signed int32 cnt[10]; // timer value when heaters turn on or off signed int32 sum; // used to sum pwm #'s float tp1_flt; // temp float variables int8 tmp1; // temp variable int8 tmp2; // temp variable int8 tmp3; // temp variable int8 lcd; // temparary int of for lcd keypad interface int8 i_temp; // temparary int for desired temp float temp[5]; // temperature (in deg C) float d_temp; // desired temperature (in deg C) signed int32 value; // temp var used to read A/D int8 chan; // A/D channel # 0-4 int8 ptavg; // # of points to average int8 value1; // temp var (4, 8 bit words -> 24 bit temp) int8 value2; int8 value3; int8 value4; int8 byte1; // temp variable int8 tmp; // temp variable int8 color; // controls red, yellow, green LED's //const float A = 3.9083E-3; // RTD constants (A) //const float AA = 1.5275E-5; // A^2 //const float B = -5.775E-7; // B //const float B2 = -1.155E-6; // 2*B //const float B4 = -2.31E-6; // 4*B ////const float R0 = 2139951; // A/D reading at 0 C (100 ohms) // Rref=392, RTD=100@0C box_tc = (100/392)*2^23 const float box_tc = 9.346E-6; // Used to convert the box A/D to temp const int16 lp_time = 40000; // timer 1 count to 40000 before continue loop const signed int32 max = 65000; // max count for PWM period 130ms const float i_max = 50; // max for int error // note: lost sign taking negative number inside sqrt (2*B is neg) // solution: first term should be pos # - sqrt # (so change sign of C) //const float C = -3383.8095; // Roko simplified EQ to const float C = 3383.8095; // Roko simplified EQ to const float C21B = 13181769; // T = -C + SQRT(C^2 - 1/B + Rt/(BR0)) //const float R0 = -0.80544186; // where C = A/(2*B) //const float R1 = -0.80545909; // and R0-R3 are the specific constants //const float R2 = -0.80541339; // 1/(BR0-3) for each RTD and //const float R3 = -0.80585980; // C21B = C^2 - 1/B const float R0 = -0.80544186; // where C = A/(2*B) //const float R1 = -0.80544186; // and R0-R3 are the specific constants //const float R2 = -0.80544186; // 1/(BR0-3) for each RTD and //const float R3 = -0.80544186; // C21B = C^2 - 1/B // the original EQ was T = (-A + SQRT(A^2 - 4B(1 - Rt/R0)))/(2B) float int_val[3]; // value of integral //const float p_gain = 12000; // proportional gain (oscillation at gain=4) const float p_gain = 25000; // proportional gain (oscillation at gain=4) const float i_gain = 500; // integral gain //#INT_TIMER1 // enable timer1 interrupt //void timer1_isr(){ // tmp3 = 8; //} void key_lcd(void){ restart_wdt(); // reset watch dog timer if (lcd == 0){ // if first time through lcd routine i_temp = d_temp; // set i_temp to desired temp putc(254); putc(88); // clear display, cursor to upper left printf("Set pt : %3u.00\n\r", i_temp); printf("<- esc, -> enter"); lcd = 1; // not 1st time through loop }else{ if (!bit_test(tmp1,6)){ // if up arrow ++i_temp; // increment temporary temp if (i_temp > 180) // check max allowed temperature i_temp = 180; lcd = 1; // not 1st time through lcd loop }else if (!bit_test(tmp1,5)){ // if down arrow --i_temp; // decrement temporary temp if (i_temp < 30) // check min allowed temperature i_temp = 30; lcd = 1; // not 1st time through lcd loop }else if (!bit_test(tmp1,7)){ // if right arrow d_temp = i_temp + 0.001; // update desired temperature (round off error) lcd = 0; // next time 1st time through lcd loop }else{ // if here then left arrow lcd = 0; // tag as last time through loop } putc(254); // move cursor to col 11 row 1 putc(71); putc(11); putc(1); if (lcd == 0) printf("%3.2f ", d_temp); else printf("%3u.00 ", i_temp); } } void pwm_calc(void){ // calculate pwm[0-2], 3 unused for (tmp3 = 0; tmp3 <= 2; ++tmp3){ tp1_flt = d_temp - temp[tmp3]; // dif between set pt & sample temp int_val[tmp3] = int_val[tmp3] + tp1_flt; // integral part if (int_val[tmp3] > i_max) // if integral has grown too large int_val[tmp3] = i_max; // integral = d_max if (int_val[tmp3] < -i_max) // if integral has grown too large int_val[tmp3] = -i_max; // integral = d_max // sum = tp1_flt * p_gain + int_val[tmp3] * i_gain; if (tmp3 == 0) // add the proportional and integral parts // sum = sum + 30000; // add offset 100C // sum = sum + 60000; // add offset 150C // sum = sum + 16000; // add offset 80C // sum = sum + 45000; // add offset 110C // sum = sum + 50000; // add offset 120C // sum = sum + 25000; // add offset 90C // sum = sum + 35000; // add offset 95C // sum = sum + 60000; // add offset 140C // sum = sum + (d_temp - (float)57) * 643; // sum = tp1_flt * p_gain + int_val[tmp3] * i_gain + (d_temp - 57) * 643; sum = tp1_flt * p_gain + int_val[tmp3] * i_gain + (d_temp - 40) * 643; else if (tmp3 == 1) sum = tp1_flt * p_gain + int_val[tmp3] * i_gain; // sum = sum + 0; // add offset else // sum = sum + 10000; // add offset 100C // sum = sum + 20000; // add offset 150C // sum = sum + 5000; // add offset 80C // sum = sum + 12000; // add offset 110C // sum = sum + 14000; // add offset 120C // sum = sum + 8000; // add offset 90C // sum = sum + 8000; // add offset 95C // sum = sum + 18000; // add offset 140C // sum = sum + (d_temp - (float)60) * 214; // sum = tp1_flt * p_gain + int_val[tmp3] * i_gain + (d_temp - 60) * 214; sum = tp1_flt * p_gain + int_val[tmp3] * i_gain + (d_temp - 58) * 214; if (sum < 11) // if negative sum = 11; // PWM = 11 if (sum > max) // if too big sum = max; // PWM = max pwm[tmp3] = sum; // set PWM value } pwm[3] = 11; // heater 3 unused } void read_chan(void){ restart_wdt(); // reset watch dog timer output_low(pin_C2); // make CS low to get data // read differential channel byte1 = 160 + chan; // byte1 = "101,SGL=0,0,A2,A1,A0" value1 = spi_read(byte1); // assign info from AD to valueX value2 = spi_read(0); value3 = spi_read(0); value4 = spi_read(0); restart_wdt(); // reset watch dog timer if ((d_temp - temp[0]) < (float)1){ // if T < 1C from setpt normal drive // --------------------------------------------------------- set_timer1(0); // clear the timer c_cnt = 1; // first heater change output_b(h_io[0]); // start proper heaters at T=0 do{ value = get_timer1(); // convert to 32 bit int if(value > cnt[c_cnt]){ // if time to change heater settings output_b(h_io[c_cnt]); // change heater outputs ++c_cnt; // point to next heater I/O change } }while(get_timer1() < max); // stay in loop until right time //output_b(h_io[c_cnt]); // all heaters off output_b(0x00); // all heaters off set_timer1(0); // clear the timer // --------------------------------------------------------- } else{ // if PWM = max all heaters on set_timer1(0); // clear the timer int_val[0] = 0; // zero out integral during ramp int_val[1] = 0; int_val[2] = 0; // take care of the differences in the heaters to heat evenly // H3 = 1, H2 = 0.96, H1 = 0.894, Period = 1.125 Sec output_high(pin_b0); // heater #3 on delay_ms(40); output_high(pin_b2); // heater #2 on delay_ms(80); output_high(pin_b1); // heater #1 on do{ // stay in loop until right time }while(get_timer1() < max); set_timer1(0); // clear the timer } delay_ms(5); // make sure A/D has time for conversion output_high(pin_C2); // set CS high tmp1 = (input_b() & 0xF0); // read keypad (internal pullups) if (tmp1 != 0xF0) // if key is pressed pin low key_lcd(); // goto lcd routine restart_wdt(); // reset watch dog timer //group all sets of data together into one integer value = make32(value1 & 0x1F, value2, value3, value4 & 0xC0); for(tmp1 = 0; tmp1 <= 5; ++tmp1) // remove 6 LSB's rotate_right(&value,4); // one bit at a time // could comment out portion below (Resistance always > 0) if ((value1 & 0x20) == 0){ // check sign bit value = value - 8388608; // convert two's compliment (2^23) } // if (chan == 1) // RTD coeficients for // tp1_flt = R0; // chan - 1 (from A/D) // if (chan == 2) // tp1_flt = R1; // if (chan == 3) // tp1_flt = R2; // if (chan == 4) // tp1_flt = R3; tp1_flt = R0; // R0 same for all RTD's if (chan == 0) tp1_flt = box_tc * (float)value; // box temp else tp1_flt = C - sqrt(C21B + tp1_flt * (float)value);//RTD temp if (chan == 2) // chan 1 tp1_flt = tp1_flt * 1.000814 + 0.135147; if (chan == 3) // chan 2 tp1_flt = tp1_flt * 1.000778 + 0.005017; // tp1_flt = tp1_flt * 1.000778 + 0.145017; if (chan == 4) // chan 3 tp1_flt = tp1_flt * 1.001005 + 0.048235; if (chan == 0) // A/D gives result from previous conversion temp[4] = 0.75 * temp[4] + 0.25 * tp1_flt; else{ if (temp[chan-1] > 20){ // average if not first sample // swap channels 2 & 3 (2 not used) if (chan == 4){ // put chan 3 into chan 2 temp[2] = 0.75 * temp[2] + 0.25 * tp1_flt; } else if (chan == 3){ // put chan 2 into chan 3 temp[3] = 0.75 * temp[3] + 0.25 * tp1_flt; } else{ // if chan 0 don't swap temp[chan-1] = 0.75 * temp[chan-1] + 0.25 * tp1_flt; } }else{ // if first sample don't average temp[chan-1] = tp1_flt; } // if (temp[chan-1] > 20){ // average if not first sample // // swap channels 2 & 3 (2 not used) // if (chan == 4){ // put chan 3 into chan 2 // temp[2] = tp1_flt; // } // else if (chan == 3){ // put chan 2 into chan 3 // temp[3] = tp1_flt; // } // else{ // if chan 0 don't swap // temp[chan-1] = tp1_flt; // } // }else{ // if first sample don't average // temp[chan-1] = tp1_flt; // } } restart_wdt(); // restart watch dog timer if (chan != 4){ // if not last time through the loop do{ // wait here until time to start next loop }while(get_timer1() < lp_time); } output_b(0x00); // all heaters off } void h_drive(void){ // drive heaters during 135ms delay while reading A/D restart_wdt(); // restart watch dog timer c_cnt = 1; // first heater change set_timer1(0); // clear the timer output_b(h_io[0]); // start proper heaters at T=0 do{ value = get_timer1(); // convert to 32 bit int if(value > cnt[c_cnt]){ // if time to change heater settings output_b(h_io[c_cnt]); // change heater outputs ++c_cnt; // point to next heater I/O change } }while(get_timer1() < max); output_b(0x00); // all heaters off set_timer1(0); // clear the timer } void h_calc(void){ // converts PWM values to start & end time for the heaters restart_wdt(); // restart watch dog timer for (c_cnt = 0; c_cnt <= 9; ++ c_cnt){ h_io[c_cnt] = 0; // zero out all heaters cnt[c_cnt] = max; // when pwm = max cnt doesn't get set so pre-set to max } h_cnt = 0; // start with the first heater c_cnt = 0; // start with the first output change cnt[c_cnt] = 0; // first heater turns on at T=0 sum = pwm[0]; // start with the first heater time bit_set(h_io[c_cnt],h_cnt); // heater 0 starts at T=0 ++c_cnt; // increment the number of times the outputs change do{ // loop through all the heaters if (sum < max){ // if the current heater finishes before the max time cnt[c_cnt] = sum; bit_clear(h_io[c_cnt],h_cnt); // turn off heater # h_cnt ++h_cnt; bit_set(h_io[c_cnt],h_cnt); // turn on the next heater ++c_cnt; // increment the number of times the outputs change if (h_cnt < 4) // pwm array index 0-3 (keep from hitting 4) sum = sum + pwm[h_cnt]; // total of all pwm's up to now }else{ // if heater past max, run it at the start for a while if (sum == max){ // if sum = max and not wrap around ++h_cnt; // skip to next heater sum = pwm[h_cnt]; // skip to next I/O }else sum = sum - max; // reset to difference (time heater should be on) bit_set(h_io[0],h_cnt); // turn on the heater at T=0 } }while(h_cnt < 4); // keep looping until 0-3 are done cnt[c_cnt] = max; // set last time to maximum h_io[c_cnt] = 0; // clear last I/O // sort the list in ascending order tmp1 = c_cnt; // save the number of I/O heater changes for (tmp3 = 1; tmp3 <= (tmp1-1); ++tmp3){ sum = max; // use sum to hold the max timer value for (c_cnt = tmp3; c_cnt <= tmp1; ++c_cnt){ if (cnt[c_cnt] < sum){ tmp2 = c_cnt; // get index of lowest timer value sum = cnt[c_cnt]; // reset min value } } sum = cnt[tmp3]; // swap timer entries cnt[tmp3] = cnt[tmp2]; cnt[tmp2] = sum; c_cnt = h_io[tmp3]; // swap I/O entries (use c_cnt because it's 8 bits) h_io[tmp3] = h_io[tmp2]; h_io[tmp2] = c_cnt; } // remove doubles (i.e. I/O changes at the same time) for (c_cnt = 1; c_cnt <= tmp1-1; ++c_cnt){ // loop through all counts if (cnt[c_cnt] == cnt[c_cnt+1]){ // if times are the same h_io[c_cnt] = h_io[c_cnt] | h_io[c_cnt+1]; // OR I/O and ++c_cnt; // skip this one for (tmp3 = c_cnt; tmp3 <= (tmp1-1); ++tmp3){ // move rest down one cnt[tmp3] = cnt[tmp3+1]; // move times down h_io[tmp3] = h_io[tmp3+1]; // move I/O down } --tmp1; // decrease the total number of I/O changes by one } } // fill in ones for overlapping heaters (keep on between start and end times) for (c_cnt = 0; c_cnt <= tmp1-2; ++c_cnt){ // loop through all I/O changes for (h_cnt = 0; h_cnt <= 3; ++h_cnt){ // loop through all heaters if (bit_test(h_io[c_cnt],h_cnt)){ // if have a 1 if (bit_test(h_io[c_cnt+1],h_cnt+1)==0) // and 0 down and to the right bit_set(h_io[c_cnt+1],h_cnt); // then put a 1 to the right of first 1 } } } } main(){ restart_wdt(); // reset watch dog timer setup_wdt(WDT_576MS); // watch dog timer overflow in 576ms setup_psp(PSP_DISABLED); // disable parallel slave port setup_adc(ADC_OFF); // disable ADC setup_adc_ports(NO_ANALOGS); // all ADC I/O are digital // use timer 1 (16 bits) to time heater I/O PWM // setup_timer_1(T1_INTERNAL|T1_DIV_BY_2); // ~131ms with 4MHz xtal setup_timer_1(T1_INTERNAL|T1_DIV_BY_8); // ~131ms with 16MHz xtal // enable TMR2 prescaler /1 prescaller, cnt to 255 before ovfl // used to set I2C clock rate when talking to A/D // setup_timer_2(T2_DIV_BY_1,255,1); // use with 4MHz xtal setup_timer_2(T2_DIV_BY_1,255,4); // use with 16MHz xtal // use TMR2 ovfl to clock spi (few KHz) // spi_L_to_H idle state for clock is low // SPI_SAMPLE_AT_END clock in SDO on rising edge of clock // setup_spi(spi_master|spi_L_to_H|spi_clk_t2|SPI_SAMPLE_AT_END); setup_spi(spi_master|spi_L_to_H|spi_clk_t2); // sample incomming data in middle of output bit #asm // start assembly code movlw 0x40 // clock data out on falling edge of clock (PIC datasheet wrong) movwf 0x94 // sspstat in bank 1 #endasm // end assembly code set_tris_a(0xFF); // port a inputs (unused) set_tris_b(0xF0); // RB7-4 in (keypad), RB3-0 out (FETs) set_tris_c(0x90); // RC4 input (SPI SDI) SCK & SDO out // RC7 input (usart RX) RC6 (TX) out // RC2 output (A/D Chip Select) set_tris_d(0x00); // port d outputs (bi-color LEDs) output_b(0x00); // all FET's off at power up output_d(0x0F); // Red LED's on at power up port_b_pullups(TRUE); // enable port b internal pullups for (chan = 0; chan <= 2; ++chan) // loop through integrals int_val[chan] = 0; // initially integrals are zero pwm[0] = 11; // heater 99.9% off (quick fix in PWM calc section) pwm[1] = 11; pwm[2] = 11; pwm[3] = 11; // set desired temperature d_temp = 30.001; // desired temperature in deg C (+ roundoff error) tp1_flt = d_temp; // so heaters don't turn on first time // temp[0] = 30.05; // temp[1] = 30.5; // temp[2] = 31.5; // temp[3] = 32.05; // goto buba; for (chan = 0; chan <= 4; ++chan) // loop through all channels temp[chan] = 0; // zero out sums for averaging // LCD setup restart_wdt(); // reset watch dog timer delay_ms(250); // delay needed otherwise text doesn't show up putc(254); putc(70); // backlight off putc(254); putc(72); // move cursor home (upper left) putc(254); putc(68); // Auto line wrap on putc(254); // move cursor to col 11 row 1 putc(71); putc(11); putc(1); printf("%3.2f ", d_temp); lcd = 0; // when change set pt will be 1st time in loop loop: for (chan = 0; chan <= 4; ++chan){ // loop through all channels read_chan(); } // conversion starts when previous data read out (now) // wait at least 133ms before reading the result // if opto-isolation doesn't work put pic to sleep for 133ms // bit 31 goes low when coversion complete // bit 30 always 0 // bit 29 = sign bit (1 = POS, 0 = NEG) // bit 28-6 = MSB - LSB (if bit 28 = 29 = 1 then Vin over range) // (if bit 28 = 29 = 0 then Vin under range) // (if bit 28 <> 29 then OK) // bit 5 = single/differential (0 = dif, 1 = singl) // bit 4-1 = channel address 0000-1111 // bit 0 = parity bit (total # of ones including parity should be even) restart_wdt(); // restart watch dog timer if (lcd == 0){ // if not changing the set point print temps putc(254); putc(72); // move cursor home (upper left) printf(" %3.3f ", temp[3]); for (tmp1 = 0; tmp1 <= 2; ++ tmp1){ putc(254); // move cursor to col 1 row 2 + tmp1 putc(71); putc(1); putc(2 + tmp1); printf(" %3.3f %5lu %2.0f ",temp[tmp1], pwm[tmp1], int_val[tmp1]); } printf("\n\r"); color = 0x0f; // assume red LED's need to be on for (tmp1 = 0; tmp1 <= 3; ++ tmp1){ tp1_flt = abs(temp[tmp1] - d_temp); if (tp1_flt < 0.1){ bit_set(color,tmp1+4); // green LED on bit_clear(color,tmp1); // red LED off // output_bit(PIN_D0,1); // green LED on // output_bit(PIN_D4,0); // red LED off }else if (tp1_flt < 1){ bit_set(color,tmp1+4); // green LED on (red is already on = yellow) // output_bit(PIN_D0,1); // green LED on (red is already on = yellow) } } output_d(color); // update LED's } restart_wdt(); // restart watch dog timer pwm_calc(); // calc pwm values from temperatures h_calc(); // calc heater on/off times from PWM values restart_wdt(); // restart watch dog timer do{ // wait here until time to start next loop }while(get_timer1() < lp_time); goto loop; }