Add max31855 driver

firmware/Makefile

@@ -154,6 +154,7 @@ CPPSRC = $(ALLCPPSRC) \
           console/binary/tunerstudio_io_serial.cpp \
           console/binary/tunerstudio_commands.cpp \
           console/binary/FragmentEntry.cpp \
+          max31855.cpp \
           main.cpp
 
 # List ASM source files here.

firmware/main.cpp

@@ -10,6 +10,9 @@
 #include "uart.h"
 #include "io_pins.h"
 #include "auxout.h"
+#include "max31855.h"
+
+#include "wideband_config.h"
 
 using namespace wbo;
 
@@ -35,6 +38,10 @@ int main() {
     InitUart();
 #endif
 
+#if (EGT_CHANNELS > 0)
+    EgtThread.Start();
+#endif
+
     while(true)
     {
         auto fault = GetCurrentFault();

firmware/max31855.cpp

@@ -0,0 +1,135 @@
+#include <math.h>
+
+#include "hal.h"
+#include "io_pins.h"
+#include "wideband_config.h"
+#include "bit.h"
+
+#include "max31855.h"
+
+#ifdef HAL_USE_SPI
+
+static SPIConfig spi_config[2] =
+{
+	{
+		.circular = false,
+		.end_cb = NULL,
+		.ssport = EGT_CS0_PORT,
+		.sspad = EGT_CS0_PIN,
+		.cr1 =
+			/* SPI_CR1_LSBFIRST | */
+			((3 << SPI_CR1_BR_Pos) & SPI_CR1_BR) |	/* div = 16 */
+			/* SPI_CR1_CPOL | */ // = 0
+			SPI_CR1_CPHA | // = 1
+			0,
+		.cr2 = 0
+	},
+	{
+		.circular = false,
+		.end_cb = NULL,
+		.ssport = EGT_CS1_PORT,
+		.sspad = EGT_CS1_PIN,
+		.cr1 =
+			/* SPI_CR1_LSBFIRST | */
+			((3 << SPI_CR1_BR_Pos) & SPI_CR1_BR) |	/* div = 16 */
+			/* SPI_CR1_CPOL | */ // = 0
+			SPI_CR1_CPHA | // = 1
+			0,
+		.cr2 = 0
+	}
+};
+
+int Max31855Thread::spi_rx(SPIDriver *spi, int ch, uint32_t *data)
+{
+	uint8_t rx[4];
+
+	/* Acquire ownership of the bus. */
+	spiAcquireBus(spi);
+	/* Setup transfer parameters. */
+	spiStart(spi, &spi_config[ch]);
+	/* Slave Select assertion. */
+	spiSelect(spi);
+	//spiExchange(spi, 4, tx, rx);
+	spiReceive(spi, 4, rx);
+	/* Slave Select de-assertion. */
+	spiUnselect(spi);
+	/* Ownership release. */
+	spiReleaseBus(spi);
+
+	if (data) {
+		*data = (rx[0] << 24) |
+				(rx[1] << 16) |
+				(rx[2] <<  8) |
+				(rx[3] <<  0);
+	}
+
+	/* no errors for now */
+	return 0;
+}
+
+int Max31855Thread::Read(int ch)
+{
+	int ret;
+	uint32_t data;
+
+	ret = spi_rx(&EGT_SPI_PORT, ch, &data);
+	if (ret)
+		return ret;
+
+	if (data == 0xffffffff) {
+		state = MAX31855_NO_REPLY;
+		return -1;
+	}
+
+	if (data & BIT(16)) {
+		if (data & BIT(0))
+			state = MAX31855_OPEN_CIRCUIT;
+		else if (data & BIT(1))
+			state = MAX31855_SHORT_TO_GND;
+		else if (data & BIT(2))
+			state = MAX31855_SHORT_TO_VCC;
+
+		int_temp[ch] = NAN;
+		temp[ch] = NAN;
+
+		return -1;
+	}
+	state = MAX31855_OK;
+
+	/* D[15:4] */
+	int16_t tmp = (data >> 4) & 0xfff;
+	/* extend sign */
+	tmp = tmp << 4;
+	tmp = tmp >> 4;	/* shifting right signed is not a good idea */
+	int_temp[ch] = (float)tmp * 0.0625;
+
+	/* D[31:18] */
+	tmp = (data >> 18) & 0x3fff;
+	/* extend sign */
+	tmp = tmp << 2;
+	tmp = tmp >> 2;	/* shifting right signed is not a good idea */
+	temp[ch] = (float) tmp * 0.25;
+
+	return 0;
+}
+
+void Max31855Thread::ThreadTask() {
+	state = MAX31855_NO_REPLY;
+
+	while (true) {
+		int ch;
+
+		for (ch = 0; ch < EGT_CHANNELS; ch++) {
+			int ret = Read(ch);
+
+			if (ret)
+				continue;
+		}
+
+        chThdSleepMilliseconds(500);
+	}
+}
+
+Max31855Thread EgtThread("egt");
+
+#endif /* HAL_USE_SPI */

firmware/max31855.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include "wideband_config.h"
+#include "thread_controller.h"
+
+#define MAX31855_THREAD_STACK 	(512)
+#define MAX31855_THREAD_PRIO	(NORMALPRIO + 1)
+
+typedef enum {
+	MAX31855_OK = 0,
+	MAX31855_OPEN_CIRCUIT = 1,
+	MAX31855_SHORT_TO_GND = 2,
+	MAX31855_SHORT_TO_VCC = 3,
+	MAX31855_NO_REPLY = 4,
+} Max31855State;
+
+class Max31855Thread : public ThreadController<MAX31855_THREAD_STACK> {
+private:
+	int spi_rx(SPIDriver *spi, int ch, uint32_t *data);
+	int Read(int ch);
+public:
+	Max31855State state;
+	float int_temp[EGT_CHANNELS];
+	float temp[EGT_CHANNELS];
+
+	Max31855Thread(const char* name)
+		: ThreadController(name, MAX31855_THREAD_PRIO)
+	{
+	}
+	void ThreadTask() override;
+};
+
+extern Max31855Thread EgtThread;

firmware/uart.cpp

@@ -5,6 +5,7 @@
 #include "lambda_conversion.h"
 #include "sampling.h"
 #include "heater_control.h"
+#include "max31855.h"
 #include "fault.h"
 #include "uart.h"
 
@@ -47,7 +48,12 @@ static void UartThread(void*)
             describeHeaterState(GetHeaterState()), duty,
             describeFault(GetCurrentFault()));
         chnWrite(&SD1, (const uint8_t *)printBuffer, writeCount);
+        chThdSleepMilliseconds(50);
 
+        writeCount = chsnprintf(printBuffer, 200,
+            "EGT: %d C (int %d C)\r\n",
+            (int)EgtThread.temp[0], (int)EgtThread.int_temp[0]);
+        chnWrite(&SD1, (const uint8_t *)printBuffer, writeCount);
         chThdSleepMilliseconds(50);
     }
 }

firmware/wideband_config.h

@@ -10,6 +10,10 @@
     #define AFR_CHANNELS 1
 #endif
 
+#ifndef EGT_CHANNELS
+    #define EGT_CHANNELS 0
+#endif
+
 // *******************************
 //    Nernst voltage & ESR sense
 // *******************************