The Instrumentation

The XG1300L contains a single axis gyroscope and a three-axis accelerometer. The directions of these axes may be seen in the picture below.

Connecting via NXT

Lego NXT is a proprietary method of consolidating an analog I/O and an I2C bus into a single 6 connector cable. This allows the same cable to be utilized for many different sensors. In order to make connecting to the LG1300L sensor easier, we used a breakout module to attach an NXT cable to the breadboard. The pinout for this breakout board may be seen below.

Noting that all NXT sensors are 5V tolerant, the mbed should be connected to the adapter using the following convention:

Below is a schematic giving a full layout of all of the connections between the mbed and the NXT breakout board.

Library API

Implementation

#include "mbed.h"
#include "LG1300L.h"

Serial pc(USBTX, USBRX); // tx, rx

I2C i2c(p28,p27);
DigitalOut LED (LED1);

int main() {
    LG1300L IMU(i2c, 2);

    while(1) {
        float angle = IMU.GetAngle();
        float ROT= IMU.GetROT();
        float X_ACC = IMU.GetACC_X();
        float Y_ACC = IMU. GetACC_Y();
        float Z_ACC = IMU. GetACC_Z();
        pc.printf("///////////////////////////////////\n");
        pc.printf("//ANGLE: %f\n", angle);
        pc.printf("//ROT: %f\n", ROT);
        pc.printf("//X-Axis: %f\n", X_ACC );
        pc.printf("//Y-Axis: %f\n", Y_ACC );
        pc.printf("//Z-axis: %f\n", Z_ACC );
        pc.printf("///////////////////////////////////\n");
        wait(1);
    }
}
    

Demos

The LG1300L_Hello_World_LCD program outputs the IMU sensor reading to the LCD display. The LCD displays both the gyroscope and the accelerometer readings. Clockwise rotation results in a positive angle from 0 to 180 degrees. Counter-clockwise rotation results in a negative angle from 0 to -179.99. Acceleration around the X-axis is displayed in Gs.

#include "mbed.h"
#include "TextLCD.h"
#include "LG1300L.h"

TextLCD lcd(p15, p16, p17, p18, p19, p20); // rs, e, d4-d7

I2C i2c(p28,p27);

int main() {
    LG1300L IMU(i2c, 2);

    while(1) {
        float angle = IMU.GetAngle();
        float X_ACC = IMU.GetACC_X();
        pc.printf("//ANGLE: %f\n", angle);
        pc.printf("//X-Axis: %f\n", X_ACC );

        wait(1);
    }
}
    

This video demonstrates the functionality of the LG1300L Hello World program.