Train slope detection

 Building instructions  Python code  Improve project

Detect the slope of the track. This lets you determine where the train is on the circuit.

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Design modifications

Build the train using the standard instructions. Mount the tilt sensor horizontally in the train, with the cable side facing towards direction of driving:

Connect the motor to port A and connect the tilt sensor to port B.

Program

This program makes the train drive until it detects a slope of 8 degrees or more. Then it drives back down.

from pybricks.pupdevices import TiltSensor, DCMotor
from pybricks.parameters import Port
from pybricks.tools import wait

# Initialize the train motor.
# If you have a motor with encoders, use the Motor class instead.
train = DCMotor(Port.A)

# Initialize the tilt sensor.
sensor = TiltSensor(Port.B)

# Measure the tilt while the train is on a flat surface.
pitch_start, roll_start = sensor.tilt()

# Start driving.
train.dc(-50)

# We need to reach a constant speed before we can check tilt again,
# because acceleration affects tilt. So we wait a second.
wait(1000)

# Wait for the train to sense the hill.
while True:
    pitch_now, roll_now = sensor.tilt()

    wait(10)

    # If we reached an extra 3 degrees, exit/break the loop.
    if pitch_now >= pitch_start + 8:
        break

# Drive backwards for a few seconds and then stop.
train.dc(40)
wait(3000)
train.dc(0)

Programming and running instructions

The train must start on a horizontal track. Then run the program.

Building instructions

• Building instructions part 1
• Building instructions part 2
• Building instructions part 3
• Building instructions part 4
• Building instructions part 5
• Building instructions part 6

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This project was submitted by The Pybricks Team.