19 const int MMA8451_I2C_ADDRESS = 0x1D << 1; // I2C bus address
20 const float MMA8451_DIGITAL_SENSITIVITY = 4096.0; // Counts/g
23 float calc_3d_vector_len(float x, float y, float z) {
24 return sqrt(x*x + y*y + z*z);
27 #define TEST_ITERATIONS 25
28 #define TEST_ITERATIONS_SKIP 5
29 #define MEASURE_DEVIATION_TOLERANCE 0.025 // 2.5%
32 MBED_HOSTTEST_TIMEOUT(15);
33 MBED_HOSTTEST_SELECT(default_auto);
34 MBED_HOSTTEST_DESCRIPTION(MMA8451Q accelerometer);
35 MBED_HOSTTEST_START("KL25Z_5");
37 DigitalOut led(LED_GREEN);
38 MMA8451Q acc(SDA, SCL, MMA8451_I2C_ADDRESS);
40 printf("WHO AM I: 0x%2X\r\n\n", acc.getWhoAmI());
42 for (int i = 0; i < TEST_ITERATIONS; i++) {
43 if (i < TEST_ITERATIONS_SKIP) {
44 // Skip first 5 measurements
47 const float g_vect_len = calc_3d_vector_len(acc.getAccX(), acc.getAccY(), acc.getAccZ()) / MMA8451_DIGITAL_SENSITIVITY;
48 const float deviation = fabs(g_vect_len - 1.0);
49 const char *succes_str = deviation <= MEASURE_DEVIATION_TOLERANCE ? "[OK]" : "[FAIL]";
50 result = result && (deviation <= MEASURE_DEVIATION_TOLERANCE);
51 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);
55 MBED_HOSTTEST_RESULT(result);