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Updating Stretch Software

Stretch's software is improved with new features and bug fixes with each update. In this guide, we cover when and how to update the various software components on your Stretch.

When to Update

We develop our software publicly on Github, allowing anyone to follow/propose the development of a code feature or bug fix. While we wholeheartedly welcome collaboration on Github, it is not necessary to be active on Github to follow our software releases. We announce every major release of software on our forum. These are stable releases with code that has been extensively tested on many Stretch robots. To be notified of new releases, create an account on the forum and click the bell icon in the top left of the announcements section. The forum is also available to report issues and ask questions about any of our software packages.

How to Update

Each Stretch is shipped with firmware, a Python SDK, and ROS packages developed specifically for Stretch. At the moment, there are three separate processes for updating each of these components.

Stretch ROS

Stretch ROS is the Robot Operating System (ROS) interface to the robot. Many robotics developers find ROS useful to bootstrap their robotics software developments. You may update it using the following commands:

$ roscd stretch_core
$ git pull

Stretch Body

Stretch Body is the Python SDK to the robot. It abstracts away the low level details of communication with the embedded devices and provides an intuitive API to working with the robot. You may update it using the following commands:

$ pip install -U hello-robot-stretch-body
$ pip install -U hello-robot-stretch-body-tools
$ pip install -U hello-robot-stretch-factory
$ pip3 install -U hello_robot_stretch_body_tools_py3

Stretch Firmware

The firmware and the Python SDK (called Stretch Body) communicate on an established protocol. Therefore, it is important to maintain a protocol match between the different firmware and Stretch Body versions. Fortunately, there is a script that handles this automatically. In the command line, run the following command:

$ REx_firmware_updater.py --status

This script will automatically determine what version is currently running on the robot and provide a recommendation for a next step. Follow the next steps provided by the firmware updater script.

Ubuntu

The operating system upon which Stretch is built is called Ubuntu. This operating system provides the underlying packages that power Stretch's software packages. Furthermore, users of Stretch depend on this operating system and the underlying packages to develop software on Stretch. Therefore, it is important to keep the OS and these underlying packages up to date. In the command line, run the following command:

$ sudo apt update
$ sudo apt upgrade

Apt is the package manager that handles updates for all Ubuntu packages.

Troubleshooting

Firmware Mismatch Error

When working with Stretch Body, if you see the following error:

----------------
Firmware protocol mismatch on /dev/XXXX.
Protocol on board is pX.
Valid protocol is: pX.
Disabling device.
Please upgrade the firmware and/or version of Stretch Body.
----------------

This error appears because the low level Python SDK and the firmware cannot communicate to each other. There is a protocol mismatch preventing communication between the two. Simply run the following script and follow its recommendations to upgrade/downgrade the firmware as necessary to match the protocol level of Stretch Body.

$ REx_firmware_updater.py --status

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