Paul van der Wielen
based on existing code, added support for max31855 and i2c display
Diff: main.cpp
- Revision:
- 0:1f9875adab5d
- Child:
- 1:e7ce82863fe9
diff -r 000000000000 -r 1f9875adab5d main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Thu Jan 16 21:48:38 2014 +0000
@@ -0,0 +1,439 @@
+//-----------------------------------------------------------------------
+// reflow oven controller, adapted to i2c display
+//
+// Version 1.0 - December 2003
+//
+// ATOM-Pro basic for Renesas '3687
+//
+// Copyright (name deleted) and it's rights are not referenced in the orignal on mbed
+//
+// This project is a port from the original basic code for the Basic Micro EVB87
+// Renesas evaluation board to the mbed in C.
+//
+// We use the same setup as the original project:
+// For the thermocouple, a Maxim 31855K, the GHI thermocouple board was used
+// For the buttons, 3 push buttons connected to ground and pullups.
+// For the heater, any driver configuration.
+//
+// fixed major bug in UpdateStateMachine() switch / case tests on wrong value
+//
+// http://www.circuitcellar.com/renesas/winners/Abstracts/H3323%20abstract.pdf
+// no info could be found on above link but use next link instead.
+// http://hobbybotics.com/projects/hobbybotics-reflow-controller-v8-03/
+//-----------------------------------------------------------------------
+
+#include "mbed.h"
+#include "lc_display.h"
+#include "max31855.h"
+
+// 0 button pressed, 1 button released
+DigitalIn Btn_0(p18);
+DigitalIn Btn_1(p19);
+DigitalIn Btn_2(p20);
+
+// 0 off, 1 on
+DigitalOut HeaterOutput(p21);
+
+// Use the USB link as serial port
+Serial pc(USBTX, USBRX); // tx, rx
+
+//SPI Interfaces
+SPI testSPI(p11,p12,p13);
+//Thermocouples
+max31855 max1(testSPI,p26);
+
+//=======================================================================
+// variables
+//=======================================================================
+
+int PreheatSlope; // 1 to 255, 1/10° per sec
+int DryingTemp; // 20 to 250, °C
+int Hysteresis; // 1 to 20, °C
+int DryingTime; // 1 to 255, seconds
+int HeatingSlope; // 1 to 255, 1/10° per sec
+int ReflowTemp; // 150 to 255, °C
+int ReflowTime; // 1 to 255, seconds
+int CoolingSlope; // 1 to 255, 1/10° per sec
+int Kd; // kd muliplier for pid, in 1/10
+
+char status; // state machine status
+int t; // current temperature
+int tini; // initial temperature
+int tset10; // set temperature times 10
+int tset; // set temperature
+int remaining_time; // remaining time in s
+char heater; // heater on/off
+int tprec; // previous temperature
+int testim; // estimated future temperature
+
+// Used to toggle between 2 display screens
+char dispcycle; // display cycle (0/1/0/1...)
+
+int alow;
+int ahigh;
+float atemp;
+
+char *lcd_status[] = {
+ "UpDry ","WtDry ","Drying ","UpFlow ","WtFlow ","Reflow ","Coolng "
+};
+
+#define PREHEAT 1
+#define WAIT_DRYING 2
+#define DRYING 3
+#define HEAT 4
+#define WAIT_REFLOW 5
+#define REFLOW 6
+#define COOLING 7
+
+void heater_off(void) {
+ HeaterOutput = 0;
+}
+
+void heater_on(void) {
+ HeaterOutput = 1;
+}
+
+//=======================================================================
+// Subroutines
+//=======================================================================
+
+// Initialisation
+void Init(void) {
+ // Welcome screen
+ _WriteLCD(ClrDisplay);
+ _WriteLCD(DisplayON_OFF, 1, 1, 0);
+ _WriteLCD(WriteString, " REFLOW CONTROL ", 0);
+ _WriteLCD(SetCursor, 0x14);
+ _WriteLCD(WriteString, " V2.0a ", 0);
+ wait_ms(1000);
+
+ // Initialize variables to default values
+ PreheatSlope = 10; // 1 to 255, 1/10° per sec
+ DryingTemp = 100; // 20 to 250, °C
+ Hysteresis = 5; // 1 to 20, °C
+ DryingTime = 120; // 1 to 255, seconds
+ HeatingSlope = 40; // 1 to 255, 1/10° per sec
+ ReflowTemp = 250; // 150 to 255, °C
+ ReflowTime = 45; // 1 to 255, seconds
+ CoolingSlope = 20; // 1 to 255, 1/10° per sec
+ Kd = 10; // 0 to 100, kd multiplier in 1/10
+
+ //Initialise chip (starts internal timer)
+ max1.initialise();
+}
+
+void editnum(int *value,int minval,int maxval) {
+ int v;
+ char tmp[32] = {0};
+ v = *value;
+
+ do {
+ wait_ms(200);
+ _WriteLCD(SetCursor, 0x0a);
+ sprintf(tmp, "%3d", v);
+ _WriteLCD(WriteString, tmp, 4);
+ _WriteLCD(SetCursor, 0x14);
+ _WriteLCD(WriteString, "[2+][1-] [0:end] ", 0);
+
+ if (Btn_1.read() == 0) {
+ v--;
+ if (v < minval) v = minval;
+ }
+
+ if (Btn_2.read() == 0) {
+ v++;
+ if (v > maxval) v = maxval;
+ }
+
+ } while (Btn_0.read() != 0);
+
+ *value = v;
+}
+
+void UpdateStateMachine(void) {
+ if (status == 0) return;
+ // original had (status - 1) but this fail to work
+ switch (status) {
+ case PREHEAT:
+ tset10 = tset10 + PreheatSlope;
+ tset = tset10/10;
+ if (tset > DryingTemp) {
+ tset10 = DryingTemp * 10;
+ status = WAIT_DRYING;
+ dispcycle = 1;
+ }
+ break;
+ case WAIT_DRYING:
+ if ((t + Hysteresis) > DryingTemp) {
+ remaining_time = DryingTime;
+ status = DRYING;
+ dispcycle = 1;
+ }
+ break;
+ case DRYING:
+ if (remaining_time == 0) {
+ remaining_time = (10 * (ReflowTemp - DryingTemp))/HeatingSlope;
+ status = HEAT;
+ dispcycle = 1;
+ }
+ break;
+ case HEAT:
+ tset10 = tset10 + HeatingSlope;
+ tset = tset10/10;
+ if (tset > ReflowTemp) {
+ tset10 = 10 * ReflowTemp;
+ status = WAIT_REFLOW;
+ dispcycle = 1;
+ }
+ break;
+ case WAIT_REFLOW:
+ if ((t + Hysteresis) > ReflowTemp) {
+ remaining_time = ReflowTime;
+ status = REFLOW;
+ dispcycle = 1;
+ }
+ break;
+
+ case REFLOW:
+ if (remaining_time == 0) {
+ remaining_time = (10 * (ReflowTemp - tini))/CoolingSlope;
+ status = COOLING;
+ dispcycle = 1;
+ }
+ break;
+ case COOLING:
+ tset10 = tset10 - CoolingSlope;
+ tset = tset10/10;
+ if (tset < tini) {
+ tset10 = 10 * tini;
+ status = 0;
+ dispcycle = 1;
+ }
+ break;
+ default:
+ status = 0;
+ break;
+ }
+}
+
+// Read current temperature from thermo couple
+// return temperature in ahigh (degrees) and alow (tens of a degree)
+void readthermo(void) {
+
+ if (max1.ready()==1){
+ //Get the reading (average value may be needed 100 ?)
+ atemp = max1.read_temp();
+
+ if (atemp > 2000){
+ if(atemp == 2001){
+ printf("No TC");
+ }else if(atemp == 2002){
+ printf("Short to Ground");
+ }else if(atemp == 2004){
+ printf("Short to VCC");
+ }
+ }else{
+ ahigh = (int) atemp;
+ alow = (int) ((atemp - ahigh) * 100);
+ }
+ }
+}
+
+void RunMode() {
+ // initialise run mode
+ status = 1;
+ dispcycle = 0;
+ t = 0;
+ readthermo();
+
+ t = ahigh;
+ tini = t;
+ tset10 = 10*t;
+ remaining_time = (10*(DryingTemp - t))/PreheatSlope;
+ heater = 0;
+
+ // wait for run button released
+ while (Btn_0.read() == 0);
+
+ wait_ms(10);
+
+ char tmp[32] = {0};
+ do {
+
+ tprec = t;
+
+ // read new temperature
+ readthermo();
+ t = ahigh;
+
+ // estimate future temperature using kd
+ testim = ((10*t) + (t-tprec) * Kd)/10;
+
+ tset = tset10/10;
+
+ _WriteLCD(ClrDisplay);
+ sprintf(tmp, "Temp: %3d C ", ahigh);
+ _WriteLCD(WriteString, tmp, 0);
+
+ _WriteLCD(SetCursor, 0x0c);
+
+ if (dispcycle == 1) {
+ sprintf(tmp, "%d/7",status);
+ _WriteLCD(WriteString, tmp, 0);
+ } else {
+ sprintf(tmp, lcd_status[status-1]);
+ _WriteLCD(WriteString, tmp, 0);
+ }
+ _WriteLCD(SetCursor, 0x14);
+ sprintf(tmp, "Tset: %3d C ", tset);
+ _WriteLCD(WriteString, tmp, 0);
+ _WriteLCD(SetCursor, 0x20);
+ sprintf(tmp, "Sec: %3d ", remaining_time);
+ _WriteLCD(WriteString, tmp, 0);
+
+
+ // decrement time (in seconds, due to the 1 second pause)
+ if (remaining_time != 0) remaining_time--;
+
+ // check if abort requested
+ if (Btn_0.read() == 0) {
+
+ status = 0;
+ heater_off();
+
+ // wait for run button released
+ while (Btn_0.read() == 0);
+ wait_ms(10);
+ }
+
+ UpdateStateMachine();
+
+ tset = tset10/10;
+
+ // control heater
+ if (heater == 0) {
+ if (testim < (tset - Hysteresis)) heater = 1;
+ }
+
+ if (heater == 1) {
+ if (testim > (tset + Hysteresis)) heater = 0;
+ }
+
+ if (heater == 0)
+ heater_off();
+ else
+ heater_on();
+
+ // send current values to uart
+ pc.printf("S %d,%d,%d,%d\n", tset, t, status, heater);
+
+ // wait for 1 second
+ wait(1);
+
+ // next dispcycle
+ dispcycle = 1 - dispcycle;
+ } while (status != 0);
+}
+
+void ConfigurationMode(void) {
+ int i;
+
+ for (i = 1; i <= 9; i++) {
+ _WriteLCD(ClrDisplay);
+ _WriteLCD(SetCursor, 0x00);
+
+ switch (i) {
+ case 1:
+ _WriteLCD(WriteString, "DrySlope", 0);
+ editnum(&PreheatSlope,1,255);
+ break;
+ case 2:
+ _WriteLCD(WriteString, "DryTemp ", 0);
+ editnum(&DryingTemp,40,150);
+ break;
+ case 3:
+ _WriteLCD(WriteString, "Hysteres", 0);
+ editnum(&Hysteresis,1,40);
+ break;
+ case 4:
+ _WriteLCD(WriteString, "DryTime ", 0);
+ editnum(&DryingTime,1,255);
+ break;
+ case 5:
+ _WriteLCD(WriteString, "HeatSlpe", 0);
+ editnum(&HeatingSlope,1,255);
+ break;
+ case 6:
+ _WriteLCD(WriteString, "FlowTemp", 0);
+ editnum(&ReflowTemp,120,255);
+ break;
+ case 7:
+ _WriteLCD(WriteString, "Flowtime", 0);
+ editnum(&ReflowTime,1,255);
+ break;
+ case 8:
+ _WriteLCD(WriteString, "CoolSlpe", 0);
+ editnum(&CoolingSlope,1,255);
+ break;
+ case 9:
+ _WriteLCD(WriteString, "Kd ", 0);
+ editnum(&Kd,0,200);
+ break;
+ }
+ }
+}
+
+//=======================================================================
+// Main program
+//=======================================================================
+
+int main(void) {
+ // Initialisations
+
+ pc.baud(9600);
+ pc.printf("\r\nReflow Oven Controller for mbed v1.0\r\n");
+
+ // define some user characters for LCD display
+ char MySymbol[2][9]= {{0x01,0x04,0x0e,0x1f,0x04,0x04,0x04,0x00,0x00},
+ {0x02,0x00,0x00,0x04,0x04,0x04,0x1f,0x0e,0x04}};
+ // use the internal pull-ups
+ Btn_0.mode(PullUp);
+ Btn_1.mode(PullUp);
+ Btn_2.mode(PullUp);
+
+ _InitLCD();
+ _WriteLCD(LCDType,0x01);
+ _WriteLCD(WriteUserDefChar,MySymbol[0],9);
+ _WriteLCD(WriteUserDefChar,MySymbol[1],9);
+
+ Init();
+
+ // Main loop
+ while (1) {
+ // heater off
+ heater_off();
+
+ // position cursor
+ _WriteLCD(SetCursor, 0x00);
+
+ // read thermo couple
+ readthermo();
+ char msg[32] = {0};
+ sprintf(msg, "Temp: %3.2f C ", atemp);
+
+ // Display current temperature
+ _WriteLCD(WriteString, msg, 0);
+
+ // Display menu
+ _WriteLCD(SetCursor, 0x14);
+ _WriteLCD(WriteString, "[1:CONF] [0:RUN] ", 0);
+
+ wait_ms(10);
+
+ // Run button ?
+ if (Btn_0.read() == 0)
+ RunMode();
+ else if (Btn_1.read() == 0)
+ ConfigurationMode();
+ }
+}