main.cpp

00001 #include "mbed.h"
00002 #include "MMA8451Q.h"
00003 #include "test_env.h"
00004 
00005 #ifdef TARGET_KL05Z
00006 #define SDA     PTB4
00007 #define SCL     PTB3
00008 
00009 #elif TARGET_K20D50M
00010 #define SDA     PTB1
00011 #define SCL     PTB0
00012 
00013 #else
00014 #define SDA     PTE25
00015 #define SCL     PTE24
00016 #endif
00017 
00018 namespace {
00019     const int MMA8451_I2C_ADDRESS = 0x1D << 1;          // I2C bus address
00020     const float MMA8451_DIGITAL_SENSITIVITY = 4096.0;   // Counts/g
00021 }
00022 
00023 float calc_3d_vector_len(float x, float y, float z) {
00024     return sqrt(x*x + y*y + z*z);
00025 }
00026 
00027 #define TEST_ITERATIONS                 25
00028 #define TEST_ITERATIONS_SKIP            5
00029 #define MEASURE_DEVIATION_TOLERANCE     0.025   // 2.5%
00030 
00031 int main(void) {
00032     MBED_HOSTTEST_TIMEOUT(15);
00033     MBED_HOSTTEST_SELECT(default_auto);
00034     MBED_HOSTTEST_DESCRIPTION(MMA8451Q accelerometer);
00035     MBED_HOSTTEST_START("KL25Z_5");
00036 
00037     DigitalOut led(LED_GREEN);
00038     MMA8451Q acc(SDA, SCL, MMA8451_I2C_ADDRESS);
00039     bool result = true;
00040     printf("WHO AM I: 0x%2X\r\n\n", acc.getWhoAmI());
00041 
00042     for (int i = 0; i < TEST_ITERATIONS; i++) {
00043         if (i < TEST_ITERATIONS_SKIP) {
00044             // Skip first 5 measurements
00045             continue;
00046         }
00047         const float g_vect_len = calc_3d_vector_len(acc.getAccX(), acc.getAccY(), acc.getAccZ()) / MMA8451_DIGITAL_SENSITIVITY;
00048         const float deviation = fabs(g_vect_len - 1.0);
00049         const char *succes_str = deviation <= MEASURE_DEVIATION_TOLERANCE ? "[OK]" : "[FAIL]";
00050         result = result && (deviation <= MEASURE_DEVIATION_TOLERANCE);
00051         printf("X:% 6d Y:% 6d Z:% 5d GF:%0.3fg, dev:%0.3f ... %s\r\n", acc.getAccX(), acc.getAccY(), acc.getAccZ(), g_vect_len, deviation, succes_str);
00052         wait(0.5);
00053         led = !led;
00054     }
00055     MBED_HOSTTEST_RESULT(result);
00056 }