Diff: main.cpp

Revision:

0:6c6060a8a2f6

Child:

1:cd2525cbbe4e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed May 28 17:32:41 2014 +0000
@@ -0,0 +1,123 @@
+#include "mbed.h"
+#include "FXOS8700CQ.h"
+
+#define DATA_RECORD_TIME_MS 1000
+
+Serial pc(USBTX, USBRX); // Primary output to demonstrate library
+
+// Pin names for FRDM-K64F
+FXOS8700CQ fxos(PTE25, PTE24, FXOS8700CQ_SLAVE_ADDR1); // SDA, SCL, (addr << 1)
+
+DigitalOut green(LED_GREEN); // waiting light
+DigitalOut blue(LED_BLUE); // collection-in-progress light
+DigitalOut red(LED_RED); // completed/error ligt
+
+Timer t; // Microsecond timer, 32 bit int, maximum count of ~30 minutes
+InterruptIn fxos_int1(PTC6); // unused, common with SW2 on FRDM-K64F
+InterruptIn fxos_int2(PTC13); // should just be the Data-Ready interrupt
+InterruptIn start_sw(PTA4); // switch SW3
+
+// Interrupt status flags and data
+bool fxos_int1_triggered = false;
+bool fxos_int2_triggered = false;
+uint32_t us_ellapsed = 0;
+bool start_sw_triggered = false;
+
+// Storage for the data from the sensor
+SRAWDATA accel_data;
+SRAWDATA magn_data;
+
+void trigger_fxos_int1(void)
+{
+    fxos_int1_triggered = true;
+}
+
+void trigger_fxos_int2(void)
+{
+    fxos_int2_triggered = true;
+    us_ellapsed = t.read_us();
+}
+
+void trigger_start_sw(void)
+{
+    start_sw_triggered = true;
+}
+
+void print_reading()
+{
+    pc.printf("%d A X:%5d,Y:%5d,Z:%5d   M X:%5d,Y:%5d,Z:%5d\r\n",
+              us_ellapsed,
+              accel_data.x, accel_data.y, accel_data.z,
+              magn_data.x, magn_data.y, magn_data.z);
+}
+
+int main(void)
+{
+    // Setup
+    t.reset();
+    pc.baud(115200); // Print quickly! 200Hz x line of output data!
+
+    // Lights off (FRDM-K64F has active-low LEDs)
+    green.write(1);
+    red.write(1);
+    blue.write(1);
+
+    // Diagnostic printing of the FXOS WHOAMI register value
+    printf("\r\n\nFXOS8700Q Who Am I= %X\r\n", fxos.get_whoami());
+
+    // Iterrupt for active-low interrupt line from FXOS
+    // Configured with only one interrupt on INT2 signaling Data-Ready
+    fxos_int2.fall(&trigger_fxos_int2);
+    fxos.enable();
+
+    // Interrupt for SW3 button-down state
+    start_sw.mode(PullUp); // Since the FRDM-K64F doesn't have its SW2/SW3 pull-ups populated
+    start_sw.fall(&trigger_start_sw);
+
+    green.write(0); // ready-green on
+
+    // Example data printing
+    fxos.get_data(&accel_data, &magn_data);
+    print_reading();
+
+    pc.printf("Waiting for data collection trigger on SW3\r\n");
+
+    while(true) {
+        if(start_sw_triggered) {
+            break;
+        }
+        wait_ms(50); // just to slow the loop, fast enough for UX
+    }
+
+    green.write(1); // ready-green off
+    blue.write(0); // working-blue on
+
+   pc.printf("Started data collection. Accelerometer at max %dg.\r\n",
+   fxos.get_accel_scale());
+
+    fxos.get_data(&accel_data, &magn_data); // clear interrupt from device
+    fxos_int2_triggered = false; // un-trigger
+
+    t.start(); // start timer and enter collection loop
+    while (t.read_ms() <= DATA_RECORD_TIME_MS) {
+
+        if(fxos_int2_triggered) {
+            fxos_int2_triggered = false; // un-trigger
+            fxos.get_data(&accel_data, &magn_data);
+            print_reading(); // outpouring of data !!
+        }
+
+        // Continuous polling of interrupt status is not efficient, but...
+        wait_us(500); // 1/10th the period of the 200Hz sample rate
+    }
+
+    blue.write(1); // working-blue off
+    red.write(0); // complete-red on
+
+    pc.printf("Done. Reset to repeat.\r\n");
+
+    while(true) {
+        pc.putc('.'); // idle dots
+        wait(1.0);
+    }
+}
\ No newline at end of file