Diff: main.cpp

Revision:

0:964606fa7e7a

--- /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);
+    }
+}
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