David Jung / Mbed OS MAX6605_Inexpensive_Analog_Temperature

Example source code for Maxim Integrated MAX6605 low-power, inexpensive analog output temperature sensor using the MAX32630FTHR analog input. The MAX6605 precision, low-power, inexpensive, analog output temperature sensor is available in a 5-pin SC70 package. The device has a +2.7V to +5.5V supply voltage range and 10µA supply current over the -55°C to +125°C temperature range.

Dependencies:   max32630fthr USBDevice

main.cpp@2:9ceed197ca58, 2019-04-27 (annotated)

Committer:
phonemacro
Date:
Sat Apr 27 10:09:59 2019 +0000
Revision:
2:9ceed197ca58
Parent:
1:9b9c2989d4eb 
initial commit;

Who changed what in which revision?

UserRevisionLine numberNew contents of line
phonemacro 0:a9f350f894e7 1 #include "mbed.h"
phonemacro 0:a9f350f894e7 2 #include "max32630fthr.h"
phonemacro 0:a9f350f894e7 3 #include "USBSerial.h"
phonemacro 0:a9f350f894e7 4
phonemacro 0:a9f350f894e7 5 MAX32630FTHR pegasus(MAX32630FTHR::VIO_3V3);
phonemacro 0:a9f350f894e7 6
phonemacro 0:a9f350f894e7 7 // Hardware serial port over DAPLink
phonemacro 0:a9f350f894e7 8 Serial daplink(P2_1, P2_0);
phonemacro 0:a9f350f894e7 9
phonemacro 0:a9f350f894e7 10 // Virtual serial port over USB
phonemacro 0:a9f350f894e7 11 USBSerial microUSB;
phonemacro 0:a9f350f894e7 12
phonemacro 0:a9f350f894e7 13 DigitalOut rLED(LED1);
phonemacro 0:a9f350f894e7 14 DigitalOut gLED(LED2);
phonemacro 0:a9f350f894e7 15 DigitalOut bLED(LED3);
phonemacro 0:a9f350f894e7 16
phonemacro 0:a9f350f894e7 17 /* Analog inputs 0 and 1 have internal dividers to allow measuring 5V signals
phonemacro 0:a9f350f894e7 18 * The dividers are selected by using inputs AIN_4 and AIN_5 respectively.
phonemacro 0:a9f350f894e7 19 * The full scale range for AIN0-3 is 1.2V
phonemacro 0:a9f350f894e7 20 * The full scale range for AIN4-5 is 6.0V
phonemacro 0:a9f350f894e7 21 */
phonemacro 0:a9f350f894e7 22 AnalogIn ain1(AIN_5);
phonemacro 0:a9f350f894e7 23 const float AIN5_FSV = 6.0f; /* Full scale value for AIN5 */
phonemacro 0:a9f350f894e7 24
phonemacro 2:9ceed197ca58 25 float celsius_to_fahrenheit(float temp_c)
phonemacro 0:a9f350f894e7 26 {
phonemacro 0:a9f350f894e7 27 float temp_f;
phonemacro 0:a9f350f894e7 28 temp_f = ((temp_c * 9)/5) + 32;
phonemacro 0:a9f350f894e7 29 return temp_f;
phonemacro 0:a9f350f894e7 30 }
phonemacro 1:9b9c2989d4eb 31
phonemacro 2:9ceed197ca58 32 void blink_timer(void) {
phonemacro 1:9b9c2989d4eb 33 gLED = !gLED; /* blink the green LED */
phonemacro 1:9b9c2989d4eb 34 }
phonemacro 1:9b9c2989d4eb 35
phonemacro 1:9b9c2989d4eb 36
phonemacro 0:a9f350f894e7 37 // main() runs in its own thread in the OS
phonemacro 0:a9f350f894e7 38 // (note the calls to Thread::wait below for delays)
phonemacro 0:a9f350f894e7 39 /**
phonemacro 2:9ceed197ca58 40 * @brief Sample main program for MAX6605
phonemacro 0:a9f350f894e7 41 * @version 1.0000.0000
phonemacro 0:a9f350f894e7 42 *
phonemacro 2:9ceed197ca58 43 * @details Sample main program for MAX6605
phonemacro 2:9ceed197ca58 44 * The MAX6605 precision, low-power, analog output temperature
phonemacro 2:9ceed197ca58 45 * sensor is available in a 5-pin SC70 (0.65 mm pitch)package.
phonemacro 2:9ceed197ca58 46 * The device has a +2.7V to +5.5V supply voltage range
phonemacro 2:9ceed197ca58 47 * and 10µA supply current over the -55°C to +125°C temperature range.
phonemacro 2:9ceed197ca58 48 * For the -40°C to +105°C temperature range, the supply voltage can go as low as +2.4V.
phonemacro 2:9ceed197ca58 49 * Supply Current: 10µA
phonemacro 2:9ceed197ca58 50 * Supply voltage: 2.7V to 5.5V
phonemacro 2:9ceed197ca58 51 * Accuracy : ±0.75°C 25°C
phonemacro 2:9ceed197ca58 52 * ±3.00°C 0.0°C to 70°C
phonemacro 2:9ceed197ca58 53 * ±3.80°C -20°C to 85°C
phonemacro 2:9ceed197ca58 54 * ±5.00°C -40°C to 100°C
phonemacro 2:9ceed197ca58 55 * ±5.80°C -55°C to 125°C
phonemacro 1:9b9c2989d4eb 56 *
phonemacro 0:a9f350f894e7 57 * The prints are sent to the terminal window (9600, 8n1).
phonemacro 0:a9f350f894e7 58 * The program sets the GPIOs to 3.3V and the program
phonemacro 0:a9f350f894e7 59 * configures the chip and reads temperatures.
phonemacro 0:a9f350f894e7 60 * To run the program, drag and drop the .bin file into the
phonemacro 0:a9f350f894e7 61 * DAPLINK folder. After it finishes flashing, cycle the power or
phonemacro 0:a9f350f894e7 62 * reset the Pegasus (MAX32630FTHR) after flashing by pressing the button on
phonemacro 0:a9f350f894e7 63 * the Pegasus next to the battery connector or the button
phonemacro 0:a9f350f894e7 64 * on the MAXREFDES100HDK.
phonemacro 0:a9f350f894e7 65 */
phonemacro 0:a9f350f894e7 66 int main()
phonemacro 0:a9f350f894e7 67 {
phonemacro 0:a9f350f894e7 68 float temperature;
phonemacro 0:a9f350f894e7 69 uint32_t i;
phonemacro 2:9ceed197ca58 70 const float A = 0.000001604f;
phonemacro 2:9ceed197ca58 71 const float B = 0.0119f;
phonemacro 2:9ceed197ca58 72 const float C1 = 0.744f;
phonemacro 0:a9f350f894e7 73 float c2;
phonemacro 0:a9f350f894e7 74 microUSB.printf("micro USB serial port\r\n");
phonemacro 0:a9f350f894e7 75 rLED = LED_OFF;
phonemacro 1:9b9c2989d4eb 76 gLED = LED_OFF;
phonemacro 0:a9f350f894e7 77 bLED = LED_OFF;
phonemacro 1:9b9c2989d4eb 78 Ticker ticker; // calls a callback repeatedly with a timeout
phonemacro 2:9ceed197ca58 79 ticker.attach(callback(&blink_timer), 1.0f); /* set timer for one second */
phonemacro 0:a9f350f894e7 80
phonemacro 2:9ceed197ca58 81 daplink.printf("MAX6605 Temperature Sensor\r\n\r\n");
phonemacro 1:9b9c2989d4eb 82
phonemacro 2:9ceed197ca58 83 temperature = (float)(((AIN5_FSV * ain1) -0.744f) / 0.0119f);
phonemacro 1:9b9c2989d4eb 84 #if 0
phonemacro 1:9b9c2989d4eb 85 daplink.printf("AIN1: %1.5f\n", (AIN5_FSV * ain1) ); // analog inputs 1
phonemacro 1:9b9c2989d4eb 86 #endif
phonemacro 0:a9f350f894e7 87
phonemacro 0:a9f350f894e7 88 daplink.printf("Temperature using Linear Approximation\r\n");
phonemacro 0:a9f350f894e7 89 for (i = 0; i < 8; i++) {
phonemacro 2:9ceed197ca58 90 temperature = (float)(((AIN5_FSV * ain1) -0.744f) / 0.0119f);
phonemacro 2:9ceed197ca58 91 daplink.printf("temperature: %3.1f degrees C, %3.1f degrees F\r\n", temperature, celsius_to_fahrenheit(temperature));
phonemacro 0:a9f350f894e7 92 wait(2);
phonemacro 0:a9f350f894e7 93 }
phonemacro 0:a9f350f894e7 94 daplink.printf("\r\n");
phonemacro 0:a9f350f894e7 95
phonemacro 0:a9f350f894e7 96 daplink.printf("Temperature using the Quadratic Equation\r\n");
phonemacro 0:a9f350f894e7 97 for (i = 0; i < 8; i++) {
phonemacro 0:a9f350f894e7 98 c2 = AIN5_FSV * ain1;
phonemacro 2:9ceed197ca58 99 temperature = (-B + sqrt(B*B - 4*A*(C1-c2)))/(2*A);
phonemacro 2:9ceed197ca58 100 daplink.printf("temperature: %3.1f degrees C C, %3.1f degrees F\r\n", temperature, celsius_to_fahrenheit(temperature));
phonemacro 0:a9f350f894e7 101 wait(2);
phonemacro 0:a9f350f894e7 102 }
phonemacro 1:9b9c2989d4eb 103 daplink.printf("\r\n\r\n");
phonemacro 0:a9f350f894e7 104
phonemacro 0:a9f350f894e7 105 while(1) {
phonemacro 0:a9f350f894e7 106 }
phonemacro 0:a9f350f894e7 107 }
phonemacro 0:a9f350f894e7 108