David Jung / Mbed OS MAX31725_High_Temperature_Accurate_IC

Sample main.c/cpp code for the Maxim Integrated MAX31725, MAX31726 high temperature sensor with accuracy of to +-0.5°C. Hosted on the MAX32630FTHR. Typical applications are for thermometers, thermostats, and high temperature alarm monitoring.

Dependencies:   MAX31725_Accurate_Temperature_Sensor max32630fthr USBDevice

Files at this revision

API Documentation at this revision

Revision 2:1890f1449f7c, committed 2019-04-10

Comitter:
phonemacro
Date:
Wed Apr 10 19:30:46 2019 +0000
Parent:
1:5d32aeb8387e
Commit message:
updated waits for one-shots

Changed in this revision

MAX31725_Accurate_Temperature_Sensor.lib Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file 
diff -r 5d32aeb8387e -r 1890f1449f7c MAX31725_Accurate_Temperature_Sensor.lib
--- a/MAX31725_Accurate_Temperature_Sensor.lib	Tue Apr 09 22:58:23 2019 +0000
+++ b/MAX31725_Accurate_Temperature_Sensor.lib	Wed Apr 10 19:30:46 2019 +0000
@@ -1,1 +1,1 @@
-https://os.mbed.com/users/phonemacro/code/MAX31725_Accurate_Temperature_Sensor/#692515ac2bb7
+https://os.mbed.com/users/phonemacro/code/MAX31725_Accurate_Temperature_Sensor/#3fa31b45fa1a

diff -r 5d32aeb8387e -r 1890f1449f7c main.cpp
--- a/main.cpp	Tue Apr 09 22:58:23 2019 +0000
+++ b/main.cpp	Wed Apr 10 19:30:46 2019 +0000
@@ -35,7 +35,21 @@
 #include "max31725.h"
 #include "max31725_cpp.h"
 #include "USBSerial.h"
- 
+
+    Serial pc(USBTX, USBRX);          // Use USB debug probe for serial link
+    Serial uart(P2_1, P2_0);
+void wait_sec_prompt(uint8_t time)
+{
+   // Ports and serial connections
+    uint32_t i;
+    for (i = 0; i < time; i++) {
+        pc.printf(".");
+        wait(1);
+    }
+    pc.printf("\r\n");
+}
+
+
 MAX32630FTHR pegasus(MAX32630FTHR::VIO_3V3); 
  
 DigitalOut rLED(LED1);
@@ -69,9 +83,10 @@
     DigitalOut gLED(LED2, LED_OFF);
     DigitalOut bLED(LED3, LED_OFF);
     gLED = LED_ON;
-    printf("MAX31725 Digital Thermometer and "
+    pc.baud(9600);                    // Baud rate = 115200
+    pc.printf("MAX31725 Digital Thermometer and "
         "Thermostat example source code.\r\n");
-    printf("\r\n");
+    pc.printf("\r\n");
     uint8_t i2c_addr = MAX31725_I2C_SLAVE_ADR_21;
     MAX31725 temp_sensor(i2cBus, i2c_addr);
     i2cBus.frequency(400000);
@@ -86,28 +101,32 @@
         wait(MAX31725_WAIT_CONV_TIME);
         temperature =
             temp_sensor.read_reg_as_temperature(MAX31725_REG_TEMPERATURE);
-        printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+        pc.printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
     }
     temp_sensor.read_cfg_reg(&cfg);
-    printf("Configuration Register = 0x%02Xh \r\n", cfg);
+    pc.printf("Configuration Register = 0x%02Xh \r\n", cfg);
 #if 0
     temp_sensor.write_trip_low_thyst(-63.9375);
     temperature =
         temp_sensor.read_reg_as_temperature(MAX31725_REG_THYST_LOW_TRIP);
-    printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
 
     temp_sensor.write_trip_high_tos(64.0625f);
     temperature = temp_sensor.read_reg_as_temperature(MAX31725_REG_TOS_HIGH_TRIP);
-    printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
-    printf("\r\n\r\n");
+    pc.printf("\r\n\r\n");
 #endif
 
-    printf("\r\n");
-
+    pc.printf("\r\n");
+    temp_sensor.write_cfg_reg(uint8_t(MAX31725_CFG_ONE_SHOT_START |
+        MAX31725_CFG_TIMEOUT_DISABLE | MAX31725_CFG_EXTENDED_FORMAT |
+        MAX31725_CFG_FAULT_FILTER_4 | MAX31725_CFG_OS_POLARITY_ACT_LOW |
+        MAX31725_CFG_COMPARATOR_MODE | MAX31725_CFG_SHUTDOWN));
     for (i = 0; i < 8; i++) {
+        wait_sec_prompt(10); /*  leave it in shutdown mode for a while */
         /* Configure for one shot, time out disabled, extended format, fault filter 4,
            active low polarity, comparator mode, shutdown
          */
@@ -118,27 +137,26 @@
         wait(MAX31725_WAIT_CONV_TIME);
         temperature =
             temp_sensor.read_reg_as_temperature(MAX31725_REG_TEMPERATURE);
-        printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+        pc.printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
-        wait(2); /*  leave it in shutdown mode for a while */
     }
     temp_sensor.read_cfg_reg(&cfg);
-    printf("Configuration Register = 0x%02Xh \r\n", cfg);
+    pc.printf("Configuration Register = 0x%02Xh \r\n", cfg);
 
-    printf("\r\n\r\n");
+    pc.printf("\r\n\r\n");
 
 #if 0
     temp_sensor.write_trip_low_thyst(-55.0f);
     temperature = 
         temp_sensor.read_reg_as_temperature(MAX31725_REG_THYST_LOW_TRIP);
-    printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
 
     temp_sensor.write_trip_high_tos(125.0f);
     temperature = temp_sensor.read_reg_as_temperature(MAX31725_REG_TOS_HIGH_TRIP);
-    printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
-    printf("\r\n\r\n");
+    pc.printf("\r\n\r\n");
 #endif
 
     /***************************************************************************
@@ -146,7 +164,7 @@
      ***************************************************************************
      */
 #include "max31725_c.h"
-    printf("C implementation of the code\r\n");
+    pc.printf("C implementation of the code\r\n");
     max31725_init(i2c_addr);
     /* Configure for time out enabled, normal format, fault filter 6,
        active low polarity, comparator mode, continuous
@@ -162,29 +180,34 @@
         wait(MAX31725_WAIT_CONV_TIME);
         temperature = max31725_read_reg_as_temperature(MAX31725_REG_TEMPERATURE,
             i2cBus);
-        printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+        pc.printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
     }
 
     max31725_read_cfg_reg(&cfg, i2cBus);
-    printf("Configuration Register = 0x%02Xh \r\n", cfg);
+    pc.printf("Configuration Register = 0x%02Xh \r\n", cfg);
 
 #if 0
     max31725_write_trip_low_thyst(-63.9375, i2cBus);
     temperature = max31725_read_reg_as_temperature(MAX31725_REG_THYST_LOW_TRIP,
         i2cBus);
-    printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, max31725_celsius_to_fahrenheit(temperature));
 
     max31725_write_trip_high_tos(64.0625f, i2cBus);
     temperature = max31725_read_reg_as_temperature(MAX31725_REG_TOS_HIGH_TRIP,
         i2cBus);
-    printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, max31725_celsius_to_fahrenheit(temperature));
 #endif
 
-    printf("\r\n");
+    pc.printf("\r\n");
+    max31725_write_cfg_reg(uint8_t(MAX31725_CFG_ONE_SHOT_START |
+        MAX31725_CFG_TIMEOUT_DISABLE | MAX31725_CFG_EXTENDED_FORMAT |
+        MAX31725_CFG_FAULT_FILTER_4 | MAX31725_CFG_OS_POLARITY_ACT_LOW |
+        MAX31725_CFG_COMPARATOR_MODE | MAX31725_CFG_SHUTDOWN), i2cBus);
     for (i = 0; i < 8; i++) {
+        wait_sec_prompt(10); /*  leave it in shutdown mode for a while */
         /* Configure for one shot, time out disabled, extended format, fault filter 4,
            active low polarity, comparator mode, shutdown
          */
@@ -195,27 +218,26 @@
         wait(MAX31725_WAIT_CONV_TIME);
         temperature = max31725_read_reg_as_temperature(MAX31725_REG_TEMPERATURE,
             i2cBus);
-        printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+        pc.printf("Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, temp_sensor.celsius_to_fahrenheit(temperature));
-        wait(2); /*  leave it in shutdown mode for a while */
     }
     max31725_read_cfg_reg(&cfg, i2cBus);
-    printf("Configuration Register = 0x%02Xh \r\n", cfg);
+    pc.printf("Configuration Register = 0x%02Xh \r\n", cfg);
 
 #if 0
     max31725_write_trip_low_thyst(-55, i2cBus);
     temperature = max31725_read_reg_as_temperature(MAX31725_REG_THYST_LOW_TRIP,
         i2cBus);
-    printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("Thyst Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, max31725_celsius_to_fahrenheit(temperature));
 
     max31725_write_trip_high_tos(125.0f, i2cBus);
     temperature = max31725_read_reg_as_temperature(MAX31725_REG_TOS_HIGH_TRIP,
         i2cBus);
-    printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
+    pc.printf("TOS Temperature = %3.4f Celsius, %3.4f Fahrenheit\r\n", 
             temperature, max31725_celsius_to_fahrenheit(temperature));
 #endif
-    printf("\r\n\r\n\r\n");
+    pc.printf("\r\n\r\n\r\n");
 
 
     while (true) {  // Blink the green LED