Diff: max31725_c.cpp

Revision:

20:c9805b01e814

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/max31725_c.cpp	Tue Apr 09 07:00:32 2019 +0000
@@ -0,0 +1,209 @@
+/*******************************************************************************
+* Copyright (C) 2019 Maxim Integrated Products, Inc., All Rights Reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining a
+* copy of this software and associated documentation files (the "Software"),
+* to deal in the Software without restriction, including without limitation
+* the rights to use, copy, modify, merge, publish, distribute, sublicense,
+* and/or sell copies of the Software, and to permit persons to whom the
+* Software is furnished to do so, subject to the following conditions:
+*
+* The above copyright notice and this permission notice shall be included
+* in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* Except as contained in this notice, the name of Maxim Integrated
+* Products, Inc. shall not be used except as stated in the Maxim Integrated
+* Products, Inc. Branding Policy.
+*
+* The mere transfer of this software does not imply any licenses
+* of trade secrets, proprietary technology, copyrights, patents,
+* trademarks, maskwork rights, or any other form of intellectual
+* property whatsoever. Maxim Integrated Products, Inc. retains all
+* ownership rights.
+*******************************************************************************
+*/
+#include "max31725.h"
+#include "max31725_c.h"
+#include "mbed.h" 
+// #include "USBSerial.h"
+
+
+/******************************************************************************/
+/*  C version for MAX31725 driver                                             */
+/******************************************************************************/
+
+/* @var max31725_write_address, max31725_read_address
+ * @brief I2C address
+ */
+uint8_t max31725_write_address, max31725_read_address;
+
+/* @var max31875_extended_format
+ * @brief Extended format, add 64°C to the temperature reading
+ */
+uint32_t max31725_extended_format;
+
+int max31725_init(uint8_t slave_address)
+{
+    max31725_write_address = (slave_address <<1);
+    max31725_read_address = ((slave_address << 1) | 1);
+    max31725_extended_format = 0;
+    return MAX31725_NO_ERROR;
+}
+ 
+/******************************************************************************/
+int max31725_read_cfg_reg(uint8_t *value, I2C &i2c_bus)
+{
+    int32_t ret;
+    char data[1] = {0};
+    char reg = MAX31725_REG_CONFIGURATION;
+
+    /* write to the Register Select, true is for repeated start */
+    ret = i2c_bus.write(max31725_write_address, &reg, 1, true);
+    if (ret == 0) {
+        ret = i2c_bus.read(max31725_read_address, data, 1, false);
+        if (ret == 0) {
+            *value = data[0];
+            return MAX31725_NO_ERROR;
+        } else {
+            printf("%s: failed to read data: ret: %d\r\n", __func__, ret);
+            }
+    } else {                
+        printf("%s: failed to write to Register Select: ret: %d\r\n",
+            __func__, ret);
+    }
+    return MAX31725_ERROR;
+}
+
+
+/******************************************************************************/
+int max31725_read_reg16(int16_t *value, char reg, I2C &i2c_bus) 
+{
+    int32_t ret;
+    char data[2] = {0, 0};
+    max31725_raw_data tmp;
+     
+    if (reg == MAX31725_REG_TEMPERATURE || 
+        reg == MAX31725_REG_THYST_LOW_TRIP || reg == MAX31725_REG_TOS_HIGH_TRIP) {
+        /* write to the Register Select, true is for repeated start */
+        ret = i2c_bus.write(max31725_write_address, &reg, 1, true);
+        /* read the two bytes of data */
+        if (ret == 0) {
+            ret = i2c_bus.read(max31725_read_address, data, 2, false);
+            if (ret == 0) {
+                tmp.msb = data[0];
+                tmp.lsb = data[1];
+                *value = tmp.swrd;
+                return MAX31725_NO_ERROR;
+            } else {
+                printf(
+                    "%s: failed to read data: ret: %d\r\n", __func__, ret);
+            }
+        } else {                
+            printf("%s: failed to write to Register Select: ret: %d\r\n",
+                __func__, ret);
+        }
+    } else {
+        printf("%s: register address is not correct: register: %d\r\n",
+                __func__, reg);
+    }                
+    return MAX31725_ERROR;
+}
+
+float max31725_read_reg_as_temperature(uint8_t reg, I2C &i2c_bus)
+{
+    max31725_raw_data tmp;
+    float temperature;
+    if (reg == MAX31725_REG_TEMPERATURE ||
+        reg == MAX31725_REG_THYST_LOW_TRIP || reg == MAX31725_REG_TOS_HIGH_TRIP) {
+        max31725_read_reg16(&tmp.swrd, reg, i2c_bus);
+        temperature = (float)tmp.swrd;  /* values are 2's complement */
+        temperature *= MAX31725_CF_LSB;
+        if (reg == MAX31725_REG_TEMPERATURE && max31725_extended_format)
+            temperature += MAX31725_EXTENDED_FORMAT_OFFSET;
+        return temperature;
+    } else {
+        printf("%s: register is invalid, %d r\n", __func__, reg);
+        return 0;
+    }
+}
+
+
+/******************************************************************************/
+int max31725_write_reg16(int16_t value, char reg, I2C &i2c_bus) 
+{
+    int32_t ret;
+    char cmd[3];
+    max31725_raw_data tmp;
+
+    if (reg >= MAX31725_REG_THYST_LOW_TRIP && reg <= MAX31725_REG_MAX) {
+        cmd[0] = reg;
+        tmp.swrd = value;
+        cmd[1] = tmp.msb;
+        cmd[2] = tmp.lsb;
+        ret = i2c_bus.write(max31725_write_address, cmd, 3, false);
+        if (ret == 0) {
+            return MAX31725_NO_ERROR;
+        } else {
+            printf("%s: I2C write error %d\r\n",__func__, ret);
+            return MAX31725_ERROR;
+        }
+    } else {
+        printf("%s: register value invalid %x\r\n",__func__, reg);
+        return MAX31725_ERROR;
+    }
+}
+
+
+int max31725_write_cfg_reg(uint8_t cfg, I2C &i2c_bus)
+{
+    int32_t ret;
+    char cmd[2];
+
+    cmd[0] = MAX31725_REG_CONFIGURATION;
+    cmd[1] = cfg;
+    ret = i2c_bus.write(max31725_write_address, cmd, 2, false);
+    if (ret == 0) {
+        max31725_extended_format = 0;
+        if (cfg & MAX31725_CFG_EXTENDED_FORMAT)
+            max31725_extended_format = 1;
+
+        return MAX31725_NO_ERROR;
+    } else {
+        printf("%s: I2C write error %d\r\n",__func__, ret);
+        return MAX31725_ERROR;
+    }
+}
+
+
+int max31725_write_trip_low_thyst(float temperature, I2C &i2c_bus)
+{
+    max31725_raw_data raw;
+    temperature /= MAX31725_CF_LSB;
+    raw.swrd = int16_t(temperature);
+    return max31725_write_reg16(raw.swrd, MAX31725_REG_THYST_LOW_TRIP, i2c_bus);
+}
+
+
+int max31725_write_trip_high_tos(float temperature, I2C &i2c_bus)
+{
+    max31725_raw_data raw;
+    temperature /= MAX31725_CF_LSB;
+    raw.swrd = int16_t(temperature);
+    return max31725_write_reg16(raw.swrd, MAX31725_REG_TOS_HIGH_TRIP, i2c_bus);
+}
+
+
+float max31725_celsius_to_fahrenheit(float temp_c)
+{
+    float temp_f;
+    temp_f = ((temp_c * 9)/5) + 32;
+    return temp_f;
+}
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