configs/stm32f103-minimum: Add board support to MAX6675 Thermocouple sensor

configs/stm32f103-minimum/src/Makefile

@@ -115,6 +115,10 @@ ifeq ($(CONFIG_SENSORS_HCSR04),y)
   CSRCS += stm32_hcsr04.c
 endif
 
+ifeq ($(CONFIG_SENSORS_MAX6675),y)
+  CSRCS += stm32_max6675.c
+endif
+
 ifeq ($(CONFIG_LCD_MAX7219),y)
   CSRCS += stm32_max7219.c
 endif

configs/stm32f103-minimum/src/stm32_bringup.c

@@ -279,6 +279,14 @@ int stm32_bringup(void)
     }
 #endif
 
+#ifdef CONFIG_SENSORS_MAX6675
+  ret = stm32_max6675initialize("/dev/temp0");
+  if (ret < 0)
+    {
+      serr("ERROR:  stm32_max6675initialize failed: %d\n", ret);
+    }
+#endif
+
 #ifdef CONFIG_CAN_MCP2515
   /* Configure and initialize the MCP2515 CAN device */
 

configs/stm32f103-minimum/src/stm32_max6675.c

@@ -0,0 +1,102 @@
+/************************************************************************************
+ * configs/stm32f4discovery/src/stm32_max6675.c
+ *
+ *   Copyright (C) 2018 Alan Carvalho de Assis. All rights reserved.
+ *   Author: Alan Carvalho de Assis <acassis@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ************************************************************************************/
+
+/************************************************************************************
+ * Included Files
+ ************************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/spi/spi.h>
+#include <nuttx/sensors/max6675.h>
+
+#include "stm32.h"
+#include "stm32_spi.h"
+#include "stm32f103_minimum.h"
+
+#if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_MAX6675) && defined(CONFIG_STM32_SPI1)
+
+/************************************************************************************
+ * Pre-processor Definitions
+ ************************************************************************************/
+
+#define MAX6675_SPI_PORTNO 1   /* On SPI1 */
+
+/************************************************************************************
+ * Public Functions
+ ************************************************************************************/
+
+/************************************************************************************
+ * Name: stm32_max6675initialize
+ *
+ * Description:
+ *   Initialize and register the MAX6675 Temperature Sensor driver.
+ *
+ * Input Parameters:
+ *   devpath - The full path to the driver to register. E.g., "/dev/temp0"
+ *
+ * Returned Value:
+ *   Zero (OK) on success; a negated errno value on failure.
+ *
+ ************************************************************************************/
+
+int stm32_max6675initialize(FAR const char *devpath)
+{
+  FAR struct spi_dev_s *spi;
+  int ret;
+
+  spi = stm32_spibus_initialize(MAX6675_SPI_PORTNO);
+
+  if (!spi)
+    {
+      return -ENODEV;
+    }
+
+  /* Then register the barometer sensor */
+
+  ret = max6675_register(devpath, spi);
+  if (ret < 0)
+    {
+      snerr("ERROR: Error registering MAX6675\n");
+    }
+
+  return ret;
+}
+
+#endif /* CONFIG_SPI && CONFIG_SENSORS_MAX6675 */
+

configs/stm32f103-minimum/src/stm32_spi.c

@@ -86,6 +86,10 @@ void stm32_spidev_initialize(void)
   (void)stm32_configgpio(GPIO_CS_MFRC522);    /* MFRC522 chip select */
 #endif
 
+#if defined(CONFIG_SENSORS_MAX6675)
+  (void)stm32_configgpio(GPIO_MAX6675_CS);    /* MAX6675 chip select */
+#endif
+
 #ifdef CONFIG_LCD_MAX7219
   (void)stm32_configgpio(STM32_LCD_CS);       /* MAX7219 chip select */
 #endif
@@ -150,6 +154,13 @@ void stm32_spi1select(FAR struct spi_dev_s *dev, uint32_t devid,
     }
 #endif
 
+#if defined(CONFIG_SENSORS_MAX6675)
+  if (devid == SPIDEV_TEMPERATURE(0))
+    {
+      stm32_gpiowrite(GPIO_MAX6675_CS, !selected);
+    }
+#endif
+
 #ifdef CONFIG_LCD_MAX7219
   if (devid == SPIDEV_DISPLAY(0))
     {

configs/stm32f103-minimum/src/stm32f103_minimum.h

@@ -135,6 +135,9 @@
 #define STM32_LCD_CS      (GPIO_OUTPUT|GPIO_CNF_OUTPP|GPIO_MODE_50MHz|\
                            GPIO_OUTPUT_SET|GPIO_PORTA|GPIO_PIN4)
 
+#define GPIO_MAX6675_CS   (GPIO_OUTPUT|GPIO_CNF_OUTPP|GPIO_MODE_50MHz|\
+                           GPIO_OUTPUT_SET|GPIO_PORTA|GPIO_PIN4)
+
 #define GPIO_MCP2515_CS   (GPIO_OUTPUT|GPIO_CNF_OUTPP|GPIO_MODE_50MHz|\
                            GPIO_OUTPUT_SET|GPIO_PORTA|GPIO_PIN4)
 
@@ -337,6 +340,18 @@ int stm32_hcsr04_initialize(FAR const char *devname);
 int stm32_lm75initialize(FAR const char *devpath);
 #endif
 
+/************************************************************************************
+ * Name: stm32_max6675initialize
+ *
+ * Description:
+ *   Called to initialize MAX6675 temperature sensor
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_SENSORS_MAX6675
+int stm32_max6675initialize(FAR const char *devpath);
+#endif
+
 /************************************************************************************
  * Name: stm32_w25initialize
  *