Putting MicroPython PyBoard into Update Mode

The MicroPython PyBoard is a popular microcontroller board that runs MicroPython, a lean and efficient implementation of the Python 3 programming language. Periodically, you may need to update the firmware on your PyBoard to access new features, bug fixes, or security patches. This blog post will guide you through the process of putting the MicroPython PyBoard into update mode, covering fundamental concepts, usage methods, common practices, and best practices.

Table of Contents#

  1. Fundamental Concepts
  2. Usage Methods
  3. Common Practices
  4. Best Practices
  5. Code Examples
  6. Conclusion
  7. References

Fundamental Concepts#

Firmware#

Firmware is the software that is permanently stored on a hardware device. In the case of the PyBoard, the firmware contains the MicroPython interpreter and other necessary components to run Python code on the board. Updating the firmware can improve the performance, functionality, and security of the PyBoard.

Update Mode#

Update mode is a special state that the PyBoard can enter to allow the firmware to be updated. When the PyBoard is in update mode, it can communicate with a computer to receive and install new firmware.

Bootloader#

The bootloader is a small program that runs when the PyBoard is powered on. It is responsible for initializing the hardware and loading the main firmware. The bootloader also provides a way to enter update mode.

Usage Methods#

Using the Bootloader#

The most common way to put the PyBoard into update mode is by using the bootloader. Here are the steps:

  1. Connect the PyBoard to your computer: Use a USB cable to connect the PyBoard to your computer.
  2. Press and hold the USR button: The USR button is a small button on the PyBoard. Press and hold it while you power on the board.
  3. Release the USR button: After the board has powered on, release the USR button. The PyBoard should now be in update mode.

Using the MicroPython REPL#

You can also put the PyBoard into update mode using the MicroPython REPL (Read-Eval-Print Loop). Here are the steps:

  1. Connect to the PyBoard: Use a serial terminal program (such as PuTTY or screen) to connect to the PyBoard's serial port.
  2. Enter the MicroPython REPL: Once connected, you should see the MicroPython REPL prompt (>>>).
  3. Run the following code:
import pyb
pyb.bootloader()

This code will put the PyBoard into update mode.

Common Practices#

Back up your code#

Before updating the firmware, it is a good idea to back up any code that you have stored on the PyBoard. You can do this by copying your Python files to your computer using a file transfer protocol (such as FTP or SFTP).

Use a stable power source#

When updating the firmware, it is important to use a stable power source. A power outage or voltage fluctuation during the update process can cause the firmware to be corrupted, which may render the PyBoard unusable.

Follow the manufacturer's instructions#

Different versions of the PyBoard may have slightly different procedures for entering update mode. It is important to follow the manufacturer's instructions carefully to ensure a successful update.

Best Practices#

Use the latest firmware#

To ensure the best performance and security, it is recommended to use the latest version of the MicroPython firmware. You can check the official MicroPython website for the latest firmware releases.

Test the new firmware#

After updating the firmware, it is a good idea to test the PyBoard to make sure that everything is working correctly. You can run some simple Python programs to verify that the board is functioning as expected.

Keep your tools up to date#

Make sure that you are using the latest version of the serial terminal program and any other tools that you use to interact with the PyBoard. This will help to ensure compatibility and avoid any issues during the update process.

Code Examples#

Using the pyb.bootloader() function#

import pyb
 
# Put the PyBoard into update mode
pyb.bootloader()

Using the machine.reset() function#

import machine
 
# Reset the PyBoard and enter the bootloader
machine.reset()

Conclusion#

Putting the MicroPython PyBoard into update mode is a relatively simple process that can be done using the bootloader or the MicroPython REPL. By following the common and best practices outlined in this blog post, you can ensure a successful firmware update and keep your PyBoard running smoothly.

References#

2025-10