Jonathan Jones
A Hello World program showing how to get temperature readings from the MLX90614 infrared temperature sensor.
Revision 0:964606fa7e7a, committed 2016-05-11
- Comitter:
- jjones646
- Date:
- Wed May 11 17:48:57 2016 +0000
- Commit message:
- Adding example program for the MLX90614 temperature sensor.
Changed in this revision
diff -r 000000000000 -r 964606fa7e7a gy-906.h
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/gy-906.h Wed May 11 17:48:57 2016 +0000
@@ -0,0 +1,34 @@
+#pragma once
+
+namespace gy906 {
+//const int default_addr = 0x5a;
+const int default_addr = 0x00;
+namespace opcode {
+ const int eeprom_access = 0x20;
+ const int ram_access = 0x00;
+ const int read_flags = 0xf0;
+ const int sleep = 0xff;
+ const int read_mask = 0x80;
+ const int write_mask = 0x00;
+}
+namespace eeprom {
+ const int T0_max = 0x00;
+ const int T0_min = 0x01;
+ const int PWMCTRL = 0x02;
+ const int Ta_range = 0x03;
+ const int EC_coef = 0x04;
+ const int config_reg1 = 0x05;
+ const int SMBus_addr = 0x0e;
+ const int id1 = 0x1c;
+ const int id2 = 0x1d;
+ const int id3 = 0x1e;
+ const int id4 = 0x1f;
+}
+namespace ram {
+ const int ir1 = 0x04;
+ const int ir2 = 0x05;
+ const int T_ambient = 0x06;
+ const int T_obj1 = 0x07;
+ const int T_obj2 = 0x08;
+}
+}
\ No newline at end of file
diff -r 000000000000 -r 964606fa7e7a main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Wed May 11 17:48:57 2016 +0000
@@ -0,0 +1,47 @@
+/*
+ * Example program showing how to get the temperature readings from
+ * an MLX90614 infrared temperature sensor using an mbed.
+ * http://www.haoyuelectronics.com/Attachment/GY-906/MLX90614.pdf
+ *
+ * Jonathan Jones
+ */
+
+#include "mbed.h"
+#include "gy-906.h"
+
+using namespace gy906;
+
+I2C i2c(p9, p10);
+const uint8_t addr = default_addr;
+
+// kelvin to fahrenheit
+float k2f(float raw_kelvin)
+{
+ return (raw_kelvin - 273.15) * 1.8 + 32;
+}
+
+// read and return one of the temperature regs
+float get_temp(uint8_t reg) {
+ char cmd[3] = { 0 };
+ // read the temperature data (kelvin)
+ cmd[0] = opcode::ram_access | reg;
+ i2c.write(addr,cmd,1,true); i2c.read(addr,cmd,3);
+ // convert to meaningful units, still in kelvin - just normalized
+ return 0.02 * static_cast<float>((cmd[1]<<8)|cmd[0]);
+}
+
+int main() {
+ uint8_t reg_addrs[] = { ram::T_ambient, ram::T_obj1 };
+ float tt = 0.0;
+ // clear terminal & hide cursor
+ printf("\033[r\033[2J\033[?25l"); fflush(stdout);
+ while (true) {
+ for (size_t i = 0; i < sizeof(reg_addrs); ++i) {
+ tt = get_temp(reg_addrs[i]);
+ printf("\r\033[KT%u:\t%.2f°F\r\n", i, k2f(tt));
+ fflush(stdout);
+ }
+ wait(0.1);
+ printf("\033[%uA", sizeof(reg_addrs)); fflush(stdout);
+ }
+}
\ No newline at end of file
diff -r 000000000000 -r 964606fa7e7a mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Wed May 11 17:48:57 2016 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/7c328cabac7e \ No newline at end of file