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Posted to commits@nuttx.apache.org by xi...@apache.org on 2023/10/06 13:15:29 UTC
[nuttx] branch master updated: max31865:RTD-to-Digital Converter
This is an automated email from the ASF dual-hosted git repository.
xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new aec0271e48 max31865:RTD-to-Digital Converter
aec0271e48 is described below
commit aec0271e480c642cc6a9bdba6af25dd209012b9b
Author: laoniaokkk <40...@qq.com>
AuthorDate: Fri Oct 6 12:10:50 2023 +0800
max31865:RTD-to-Digital Converter
---
drivers/sensors/Kconfig | 7 +
drivers/sensors/Make.defs | 6 +
drivers/sensors/max31865.c | 334 +++++++++++++++++++++++++++++++++++++++
include/nuttx/sensors/max31865.h | 86 ++++++++++
4 files changed, 433 insertions(+)
diff --git a/drivers/sensors/Kconfig b/drivers/sensors/Kconfig
index 6e0a2d77ad..76094fba17 100644
--- a/drivers/sensors/Kconfig
+++ b/drivers/sensors/Kconfig
@@ -1091,6 +1091,13 @@ config SENSORS_MAX31855
---help---
Enables support for the MAX31855 driver
+config SENSORS_MAX31865
+ bool "Maxim MAX31865 Driver"
+ default n
+ select SPI
+ ---help---
+ Enables support for the MAX31865 driver
+
config SENSORS_MAX6675
bool "Maxim MAX6675 Driver"
default n
diff --git a/drivers/sensors/Make.defs b/drivers/sensors/Make.defs
index a6eff1f5ad..65d7448d5f 100644
--- a/drivers/sensors/Make.defs
+++ b/drivers/sensors/Make.defs
@@ -386,6 +386,12 @@ ifeq ($(CONFIG_SENSORS_HDC1008),y)
CSRCS += hdc1008.c
endif
+# ANALOG MAX31865
+
+ifeq ($(CONFIG_SENSORS_MAX31865),y)
+ CSRCS += max31865.c
+endif
+
# Include sensor driver build support
DEPPATH += --dep-path sensors
diff --git a/drivers/sensors/max31865.c b/drivers/sensors/max31865.c
new file mode 100644
index 0000000000..e998debe96
--- /dev/null
+++ b/drivers/sensors/max31865.c
@@ -0,0 +1,334 @@
+/****************************************************************************
+ * drivers/sensors/max31865.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/* Character driver for the Maxim MAX31865 Thermocouple-to-Digital Converter
+ *
+ * NOTE: Some Maxim MAX31865 chips have an issue it report value 25% lower
+ * of real temperature, for more info read this thread:
+ * http://www.eevblog.com/forum/projects/max31865-temperature-error/
+ */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <fixedmath.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+#include <math.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/fs/fs.h>
+#include <nuttx/spi/spi.h>
+#include <nuttx/sensors/max31865.h>
+#include <nuttx/random.h>
+#include <sys/endian.h>
+
+#if defined(CONFIG_SPI) && defined(CONFIG_SENSORS_MAX31865)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private
+ ****************************************************************************/
+
+#define MAX31865_CONFIG_REG 0x00
+# define MAX31865_BIAS_ON (1 << 7)
+# define MAX31865_AUTO_CONVERSION (1 << 6)
+# define MAX31865_ONE_SHOT (1 << 5)
+# define MAX31865_3WIRE (1 << 4)
+# define MAX31865_FAULT_DET_OFFSET (2)
+# define MAX31865_FAULT_DET_MASK (3 << MAX31865_FAULT_DET_OFFSET)
+# define MAX31865_FAULT_DET_OFF (0 << MAX31865_FAULT_DET_OFFSET)
+# define MAX31865_FAULT_DET_AUTO (1 << MAX31865_FAULT_DET_OFFSET)
+# define MAX31865_FAULT_DET_1CYCLE (2 << MAX31865_FAULT_DET_OFFSET)
+# define MAX31865_FAULT_DET_2CYCLE (3 << MAX31865_FAULT_DET_OFFSET)
+# define MAX31865_FAULT_STATUS_CLR (1 << 1)
+# define MAX31865_50HZ_FILTER (1 << 0)
+
+#define MAX31865_RTDMSB_REG 0x01
+#define MAX31865_RTDLSB_REG 0x02
+#define MAX31865_HFAULTMSB_REG 0x03
+#define MAX31865_HFAULTLSB_REG 0x04
+#define MAX31865_LFAULTMSB_REG 0x05
+#define MAX31865_LFAULTLSB_REG 0x06
+#define MAX31865_FAULTSTAT_REG 0x07
+
+#define MAX31865_REF_RESISTOR 430
+
+#define MAX31865_WRITE 0x80
+
+#define RTD_A (3.9083e-3)
+#define RTD_B (-5.775e-7)
+
+struct max31865_dev_s
+{
+ FAR struct spi_dev_s *spi; /* Saved SPI driver instance */
+ int16_t temp;
+ uint16_t devid; /* Select minor device number */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static void max31865_lock(FAR struct spi_dev_s *spi);
+static void max31865_unlock(FAR struct spi_dev_s *spi);
+
+/* Character driver methods */
+
+static int max31865_open(FAR struct file *filep);
+
+static ssize_t max31865_read(FAR struct file *filep, FAR char *buffer,
+ size_t buflen);
+static ssize_t max31865_write(FAR struct file *filep, FAR const char *buffer,
+ size_t buflen);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations g_max31865fops =
+{
+ max31865_open, /* open */
+ NULL, /* close */
+ max31865_read, /* read */
+ max31865_write, /* write */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: max31865_lock
+ *
+ * Description:
+ * Lock and configure the SPI bus.
+ *
+ ****************************************************************************/
+
+static void max31865_lock(FAR struct spi_dev_s *spi)
+{
+ SPI_LOCK(spi, true);
+ SPI_SETMODE(spi, SPIDEV_MODE1);
+ SPI_SETBITS(spi, 8);
+ SPI_HWFEATURES(spi, 0);
+ SPI_SETFREQUENCY(spi, 400000);
+}
+
+/****************************************************************************
+ * Name: max31865_unlock
+ *
+ * Description:
+ * Unlock the SPI bus.
+ *
+ ****************************************************************************/
+
+static void max31865_unlock(FAR struct spi_dev_s *spi)
+{
+ SPI_LOCK(spi, false);
+}
+
+/****************************************************************************
+ * Name: max31865_open
+ *
+ * Description:
+ * This function is called whenever the MAX31865 device is opened.
+ *
+ ****************************************************************************/
+
+static int max31865_open(FAR struct file *filep)
+{
+ FAR struct inode *inode = filep->f_inode;
+ FAR struct max31865_dev_s *priv = inode->i_private;
+ unsigned char regval;
+
+ /* Enable MAX31865's chip select */
+
+ max31865_lock(priv->spi);
+ SPI_SELECT(priv->spi, SPIDEV_TEMPERATURE(priv->devid), true);
+
+ regval = MAX31865_WRITE | MAX31865_CONFIG_REG;
+ SPI_SEND(priv->spi, regval);
+
+ regval = MAX31865_50HZ_FILTER | MAX31865_3WIRE | \
+ MAX31865_AUTO_CONVERSION | MAX31865_BIAS_ON;
+ SPI_SEND(priv->spi, regval);
+
+ /* Disable MAX31865's chip select */
+
+ SPI_SELECT(priv->spi, SPIDEV_TEMPERATURE(priv->devid), false);
+ max31865_unlock(priv->spi);
+
+ return OK;
+}
+
+/****************************************************************************
+ * Name: max31865_read
+ ****************************************************************************/
+
+static ssize_t max31865_read(FAR struct file *filep, FAR char *buffer,
+ size_t buflen)
+{
+ FAR struct inode *inode = filep->f_inode;
+ FAR struct max31865_dev_s *priv = inode->i_private;
+ uint8_t regval[8];
+ float temp;
+ uint16_t regmsb;
+ float rt;
+
+ /* Check for issues */
+
+ if (!buffer)
+ {
+ snerr("ERROR: Buffer is null\n");
+ return -EINVAL;
+ }
+
+ if (buflen != sizeof(float))
+ {
+ snerr("ERROR: You can't read something other than 16 bits "
+ "(2 bytes)\n");
+ return -EINVAL;
+ }
+
+ /* Enable MAX31865's chip select */
+
+ max31865_lock(priv->spi);
+ SPI_SELECT(priv->spi, SPIDEV_TEMPERATURE(priv->devid), true);
+
+ /* Read temperature */
+
+ memset(regval, 0, sizeof(regval));
+ SPI_SEND(priv->spi, MAX31865_CONFIG_REG);
+
+ SPI_RECVBLOCK(priv->spi, regval, sizeof(regval));
+
+ /* Disable MAX31865's chip select */
+
+ SPI_SELECT(priv->spi, SPIDEV_TEMPERATURE(priv->devid), false);
+ max31865_unlock(priv->spi);
+
+ /* Detect any errors during SPI transmission */
+
+ if (*regval != (MAX31865_50HZ_FILTER | MAX31865_3WIRE | \
+ MAX31865_AUTO_CONVERSION | MAX31865_BIAS_ON))
+ {
+ snerr("ERROR: Data transmission failed on device %d:\n", priv->devid);
+ snerr(" One or more MAX31865 pins are not properly connected!\n\n");
+ return -EINVAL;
+ }
+
+ /* Resistance of the RTD */
+
+ regmsb = ((regval[1] << 8) | regval[2]) >> 1;
+
+ rt = (float)(regmsb * MAX31865_REF_RESISTOR / 32768.0);
+
+ /* T = (-A + sqrt(A^2 - 4*B*(1 - R/R0))) / (2*B) */
+
+ temp = (-RTD_A + sqrt(RTD_A * RTD_A - 4 * RTD_B * (1 - rt / 100.0))) \
+ / (2 * RTD_B);
+
+ *(float *)buffer = temp;
+
+ sninfo("MAX31865 ADC: %d, RTD: %.2f, temperature: %.1f\n", \
+ regmsb, rt, temp);
+
+ return sizeof(temp);
+}
+
+/****************************************************************************
+ * Name: max31865_write
+ ****************************************************************************/
+
+static ssize_t max31865_write(FAR struct file *filep, FAR const char *buffer,
+ size_t buflen)
+{
+ return -ENOSYS;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: max31865_register
+ *
+ * Description:
+ * This function will register the max31865 driver as /dev/tempN
+ * where N is the minor device number
+ *
+ * Input Parameters:
+ * devpath - The full path to the driver to register. E.g., "/dev/temp0"
+ * spi - An instance of the SPI interface to use to communicate with
+ * MAX31865
+ * devid - Minor device number. E.g., 0, 1, 2, etc.
+ *
+ * Returned Value:
+ * Zero is returned on success. Otherwise, a negated errno value is
+ * returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int max31865_register(FAR const char *devpath, FAR struct spi_dev_s *spi,
+ uint16_t devid)
+{
+ FAR struct max31865_dev_s *priv;
+ int ret;
+
+ /* Sanity check */
+
+ DEBUGASSERT(spi != NULL);
+
+ /* Initialize the MAX31865 device structure */
+
+ priv = (FAR struct max31865_dev_s *)
+ kmm_malloc(sizeof(struct max31865_dev_s));
+ if (priv == NULL)
+ {
+ snerr("ERROR: Failed to allocate instance\n");
+ return -ENOMEM;
+ }
+
+ priv->spi = spi;
+ priv->temp = 0;
+ priv->devid = devid;
+
+ /* Register the character driver */
+
+ ret = register_driver(devpath, &g_max31865fops, 0666, priv);
+ if (ret < 0)
+ {
+ snerr("ERROR: Failed to register driver: %d\n", ret);
+ kmm_free(priv);
+ }
+
+ return ret;
+}
+#endif /* CONFIG_SPI && CONFIG_SENSORS_MAX31865 */
diff --git a/include/nuttx/sensors/max31865.h b/include/nuttx/sensors/max31865.h
new file mode 100644
index 0000000000..afae126a28
--- /dev/null
+++ b/include/nuttx/sensors/max31865.h
@@ -0,0 +1,86 @@
+/****************************************************************************
+ * include/nuttx/sensors/max31865.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_SENSORS_MAX31865_H
+#define __INCLUDE_NUTTX_SENSORS_MAX31865_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <nuttx/irq.h>
+
+#if defined(CONFIG_SENSORS_MAX31865)
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#define MAX31865_SPI_MAXFREQ 4000000
+
+struct spi_dev_s;
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: max31865_register
+ *
+ * Description:
+ * This function will register the max31865 driver as /dev/tempN
+ * where N is the minor device number.
+ *
+ * Input Parameters:
+ * devpath - The full path to the driver to register. E.g., "/dev/temp0"
+ * spi - An instance of the SPI interface to use to communicate with
+ * MAX31865
+ * devid - Minor device number. E.g., 0, 1, 2, etc.
+ *
+ * Returned Value:
+ * Zero is returned on success. Otherwise, a negated errno value is
+ * returned to indicate the nature of the failure.
+ *
+ ****************************************************************************/
+
+int max31865_register(FAR const char *devpath,
+ FAR struct spi_dev_s *spi,
+ uint16_t devid);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_SENSORS_MAX31865 */
+#endif /* __INCLUDE_NUTTX_SENSORS_MAX31865_H */