ENG-CANSAT-PICO-MISSION1-AUTONOMOUS

Introduction

Until now, we have worked with the emitter linked to a computer via USB cable.

Using the USB cable was very useful to capture the debugging message into the REPL Session.

We have two things to do:

• Start automatically your python script
• Making the CANSAT working autonomously

Start your Python script

If you want your script to start when powering up your Pico, just copy the script content into a file named main.py .

This approach is very efficient but can lead to plateform lock-up when the script is buggy or contains an infinite loop.

The aim is to check the status of a given pin (eg: GP22) before starting the user script (say user.py).

In case of trouble during testing/development we just switch-off the "RunApp" and press the reset button to restart the Pico.

Here is the content of main.py script.

from machine import Pin
run = Pin( 22, Pin.IN, Pin.PULL_UP )
if run.value() == 1:
    import user # load user.py file and execute it

To resume:

• If the RunApp switch is on the Run position at power-up the user.py script does start.
• If the RunApp switch is on the Stop position at power-up the user.py script will not start.

Power It

To work autonomously, the CanSat must be powered with a battery.

This point have been adressed with details in the following section.

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Written by Meurisse D. for MCHobby