# HG changeset patch
# User Ethan Zonca <e@ethanzonca.com>
# Date 2017-06-26 18:19:08
# Node ID f602474ad6c6f41b04287e90c8019b5c5d9cbb56
# Parent  2b4eb31dd8da193e1aee1c699d8ccf1ef51184a2

Initial work on max31856 driver, etc

diff --git a/inc/states.h b/inc/states.h
--- a/inc/states.h
+++ b/inc/states.h
@@ -27,6 +27,7 @@ typedef union
         int32_t setpoint_brew;
         int32_t setpoint_steam;
         uint32_t control_mode;
+        uint32_t sensor_type;
         uint32_t plant_type;
         uint32_t hysteresis;
     } val;
@@ -41,7 +42,8 @@ enum tempunits {
 
 enum state {
     STATE_IDLE = 0,
-    
+
+	STATE_SETSENSORTYPE,
     STATE_SETMODE,
     STATE_SETPLANTTYPE,
     STATE_SETHYSTERESIS,
@@ -89,4 +91,14 @@ enum RESET_MODE {
 	RESET_SIZE,
 };
 
+enum SENSOR_TYPE {
+	SENSOR_NTC = 0,
+	SENSOR_TC_K,
+	SENSOR_TC_E,
+	SENSOR_TC_N,
+	SENSOR_TC_R,
+	SENSOR_TC_S,
+	SENSOR_TC_T,
+};
+
 #endif
diff --git a/lib/max31856/max31856.c b/lib/max31856/max31856.c
new file mode 100644
--- /dev/null
+++ b/lib/max31856/max31856.c
@@ -0,0 +1,59 @@
+//
+// MAX31856: Driver to configure and read temperature from the MAX31856 thermoouple-to-Digital IC
+//
+
+#include "max31856.h"
+#include "states.h"
+
+// Private variables
+static float temp_latest = 0.0;
+static float temp_avg = 0.0;
+
+static SPI_HandleTypeDef* spiport;
+
+
+// Initialize the MAX31856 driver
+void max31856_init(SPI_HandleTypeDef* spi_port, GPIO_TypeDef* cs_port, uint32_t cs_pin, uint32_t sensor_type)
+{
+	// Set SPI port reference
+	spiport = spi_port;
+
+	// Configure the CS pin for output
+	GPIO_InitTypeDef GPIO_InitStruct;
+	GPIO_InitStruct.Pin = cs_pin;
+	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+	GPIO_InitStruct.Pull = GPIO_NOPULL;
+	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+	HAL_GPIO_Init(cs_port, &GPIO_InitStruct);
+
+	// MAX31856
+	// - set to continuous conversion mode
+	// - probably no filtering, we'll do that on this side of things
+	// - set up to read the typical open/short faults but not the high/low alarms
+
+	uint8_t data[] = {0,0,0,0};
+	HAL_SPI_Transmit(spiport, data, 1, 100);
+
+	// sensor type - could we just mask bits off? maybe optimize the enum for this
+}
+
+void max31856_process(void)
+{
+	// Read temperature from the MAX31856 (approx 10hz optimally)
+	uint8_t data[] = {0,0,0,0};
+	HAL_SPI_Transmit(spiport, data, 1, 100);
+
+}
+
+
+// Return latest temperature reading (unaveraged, deg C)
+float max31856_latest_temp(void)
+{
+	return temp_latest;
+}
+
+// Return average temperature reading (deg C)
+float max31856_avg_temp(void)
+{
+	return temp_latest;
+}
diff --git a/lib/max31856/max31856.h b/lib/max31856/max31856.h
new file mode 100644
--- /dev/null
+++ b/lib/max31856/max31856.h
@@ -0,0 +1,7 @@
+#ifndef MAX31856_H
+#define MAX31856_H
+
+#include "stm32f3xx_hal.h"
+
+
+#endif
diff --git a/src/display.c b/src/display.c
--- a/src/display.c
+++ b/src/display.c
@@ -114,7 +114,7 @@ void display_process(void)
                         status->state = STATE_PREHEAT;
                         break;
                     case MODE_SETUP:
-                        status->state = STATE_SETMODE;
+                        status->state = STATE_SETSENSORTYPE;
                         break;
                     case MODE_RESET:
                         status->state = STATE_RESET;
@@ -149,6 +149,32 @@ void display_process(void)
 
 
 
+        case STATE_SETSENSORTYPE:
+        {
+            // Write text to OLED
+            // [ therm :: set mode ]
+            // [ m =          ]
+            ssd1306_drawstring("Sensor Type", 0, 40);
+            ssd1306_drawlogo();
+
+            // change scope to global?
+            char* sensor_lookup[] = {"NTC", "K  ", "E  ", "N  ", "R  ", "S  ", "T  "};
+			ssd1306_drawstring(sensor_lookup[set->val.sensor_type], 1, 60);
+            ssd1306_drawstring("Press to accept", 3, 40);
+
+            // Button handler
+            if(SW_BTN_PRESSED) {
+                status->state = STATE_SETMODE;
+            }
+            else
+            {
+            	user_input((uint16_t*)&set->val.hysteresis);
+            }
+            // Event Handler
+            // N/A
+
+        } break;
+
         case STATE_SETMODE:
         {
             // Write text to OLED
diff --git a/src/pid.c b/src/pid.c
--- a/src/pid.c
+++ b/src/pid.c
@@ -20,38 +20,39 @@ void pid_init()
 float pid_process(void)
 {
 
+
 //            #ifdef MAX31865_RTD_SENSOR
 //            max31865_readtemp(spi_get(), &set, &status);
 //			#else
 //			max31855_readtemp(spi_get(), &set, &status); // Read MAX31855
 //			#endif
 
-		float ssr_output = 0;
+	float ssr_output = 0;
 
 
-		if(runtime_status()->pid_enabled)
-		{
-			// Get ssr output for next time
-			int16_t power_percent = pid_update();
+	if(runtime_status()->pid_enabled)
+	{
+		// Get ssr output for next time
+		int16_t power_percent = pid_update();
 
-			if(flash_getsettings()->val.plant_type == PLANT_HEATER)
-				power_percent *= -1;
+		if(flash_getsettings()->val.plant_type == PLANT_HEATER)
+			power_percent *= -1;
 
-			//power-percent is 0-1000?
-			ssr_output = power_percent; //(((uint32_t)SSR_PERIOD * (uint32_t)10 * (uint32_t)100) * power_percent) / (uint32_t)1000000;
+		//power-percent is 0-1000?
+		ssr_output = power_percent; //(((uint32_t)SSR_PERIOD * (uint32_t)10 * (uint32_t)100) * power_percent) / (uint32_t)1000000;
 
-			// put ssr output on display
-			ssd1306_drawstring("      ", 0, 90); //fixme: this is bad, but I can't get the old digits to clear otherwise
-			char tempstr[6];
-			itoa(ssr_output, tempstr, 10);
-			ssd1306_drawstring(tempstr, 0, 90);
-		}
-		else
-		{
-			ssr_output = 0.0;
-		}
+		// put ssr output on display
+		ssd1306_drawstring("      ", 0, 90); //fixme: this is bad, but I can't get the old digits to clear otherwise
+		char tempstr[6];
+		itoa(ssr_output, tempstr, 10);
+		ssd1306_drawstring(tempstr, 0, 90);
+	}
+	else
+	{
+		ssr_output = 0.0;
+	}
 
-		return ssr_output;
+	return ssr_output;
 }
 
 int16_t pid_update(void)
@@ -59,50 +60,50 @@ int16_t pid_update(void)
 	therm_status_t* status = runtime_status();
 	therm_settings_t* set = flash_getsettings();
 
-  // Convert temperature to fixed point number with 1/10th resolution
-  float temp = status->temp;
+	// Convert temperature to fixed point number with 1/10th resolution
+	float temp = status->temp;
 
-  // Calculate instantaneous error
-  int16_t error = status->setpoint * 10 - temp; // TODO: Use fixed point fraction
+	// Calculate instantaneous error
+	int16_t error = status->setpoint * 10 - temp; // TODO: Use fixed point fraction
 
-  // Proportional component
-  int32_t p_term = set->val.k_p * error;
+	// Proportional component
+	int32_t p_term = set->val.k_p * error;
 
-  // Error accumulator (integrator)
-  state.i_state += error;
+	// Error accumulator (integrator)
+	state.i_state += error;
 
-  // to prevent the iTerm getting huge from lots of 
-  //  error, we use a "windup guard" 
-  // (this happens when the machine is first turned on and
-  // it cant help be cold despite its best efforts)
-  // not necessary, but this makes windup guard values 
-  // relative to the current iGain
-  int32_t windup_guard_res = (set->val.windup_guard * 10) / set->val.k_i;
+	// to prevent the iTerm getting huge from lots of
+	//  error, we use a "windup guard"
+	// (this happens when the machine is first turned on and
+	// it cant help be cold despite its best efforts)
+	// not necessary, but this makes windup guard values
+	// relative to the current iGain
+	int32_t windup_guard_res = (set->val.windup_guard * 10) / set->val.k_i;
 
-  // Calculate integral term with windup guard 
-  if (state.i_state > windup_guard_res)
+	// Calculate integral term with windup guard
+	if (state.i_state > windup_guard_res)
 	  state.i_state = windup_guard_res;
-  else if (state.i_state < -windup_guard_res)
+	else if (state.i_state < -windup_guard_res)
 	  state.i_state = -windup_guard_res;
 
-  int32_t i_term = set->val.k_i * state.i_state;
+	int32_t i_term = set->val.k_i * state.i_state;
 
-  // Calculate differential term (slope since last iteration)
-  int32_t d_term = (set->val.k_d * (temp - state.last_pid_temp));
+	// Calculate differential term (slope since last iteration)
+	int32_t d_term = (set->val.k_d * (temp - state.last_pid_temp));
 
-  // Save temperature for next iteration
-  state.last_pid_temp = temp;
+	// Save temperature for next iteration
+	state.last_pid_temp = temp;
 
-  int16_t result = (p_term + i_term - d_term) / 10;
+	int16_t result = (p_term + i_term - d_term) / 10;
 
-  // Put out tenths of percent, 0-1000. 
-  if(result > 1000)
-    result = 1000;
-  else if(result < -1000)
-    result = -1000;
+	// Put out tenths of percent, 0-1000.
+	if(result > 1000)
+	result = 1000;
+	else if(result < -1000)
+	result = -1000;
 
-  // Return feedback
-  return result;
+	// Return feedback
+	return result;
 }
 
 
diff --git a/src/tempsense.c b/src/tempsense.c
--- a/src/tempsense.c
+++ b/src/tempsense.c
@@ -8,13 +8,35 @@
 
 void tempsense_init(void)
 {
+	// Maybe don't perform temp sensor setup in here, but in readtemp?
+	// what happens if the user changes the tempsense type while running?
+	// we need to re-init...
+
 
 }
 
+// Returns the latest reading from the configured temperature sensor
 float tempsense_readtemp(void)
 {
-	// TODO: Support multiple temperature sensors
 
+	switch(flash_getsettings()->val.sensor_type)
+	{
+		case SENSOR_TC_K:
+		case SENSOR_TC_E:
+		case SENSOR_TC_N:
+		case SENSOR_TC_R:
+		case SENSOR_TC_S:
+		case SENSOR_TC_T:
+		{
+			// Read MAX31856
+		} break;
+
+		case SENSOR_NTC:
+		{
+			// Read analog value from internal ADC, linearize the reading, etc
+		} break;
+
+	}
 
 	// either return latest reading from DMA loop (NTC, etc)
 	// or initiate a blocking read and return it.