
Arduino Quick Start
CoreMatrix IMU attitude sensor input APIs and example program.
3.3.10-aM5CoreMatrix0.2.290.2.36This example reads acceleration and angular velocity data under normal power-on conditions and maps the tilt direction onto the 16 x 16 LED matrix.
#include <M5Unified.h>
static void drawStatus(bool ready, int x = 7, int y = 7)
{
M5.Display.startWrite();
M5.Display.fillScreen(TFT_BLACK);
M5.Display.drawRect(0, 0, 16, 16, TFT_WHITE);
if (!ready) {
M5.Display.drawLine(3, 3, 12, 12, TFT_WHITE);
M5.Display.drawLine(12, 3, 3, 12, TFT_WHITE);
} else {
M5.Display.fillRect(7, 7, 2, 2, TFT_WHITE);
M5.Display.fillRect(x, y, 3, 3, TFT_WHITE);
}
M5.Display.endWrite();
M5.Display.display();
}
void setup()
{
auto cfg = M5.config();
cfg.serial_baudrate = 115200;
M5.begin(cfg);
M5.Display.setColorDepth(8);
M5.Display.setRotation(1);
M5.Display.setBrightness(128);
Serial.printf("BMI270 enabled: %s\n", M5.Imu.isEnabled() ? "yes" : "no");
drawStatus(M5.Imu.isEnabled());
}
void loop()
{
if (!M5.Imu.isEnabled()) {
delay(1000);
return;
}
const auto updated = M5.Imu.update();
if (updated & m5::IMU_Class::sensor_mask_accel) {
const auto& data = M5.Imu.getImuData();
const int x = constrain(static_cast<int>((data.accel.y + 1.0f) * 7.5f), 1, 13);
const int y = constrain(static_cast<int>((data.accel.x + 1.0f) * 7.5f), 1, 13);
drawStatus(true, x, y);
Serial.printf("ax: %.3f ay: %.3f az: %.3f\n",
data.accel.x, data.accel.y, data.accel.z);
Serial.printf("gx: %.3f gy: %.3f gz: %.3f\n",
data.gyro.x, data.gyro.y, data.gyro.z);
}
delay(50);
}A center dot remains in the middle of the matrix, and a 3 x 3 square moves according to the acceleration data. The serial monitor outputs the acceleration and angular velocity. If the display direction is opposite to the enclosure orientation, swap x/y in the coordinate calculation or invert the corresponding axis.
The CoreMatrix IMU section uses IMU_Class from the M5Unified library. For more IMU-related APIs, refer to the following documentation: