MicroPython Package Installer (UPIP)

Welcome to UPIP!

In this lab you will install extra Python libraries directly onto your Pico W — straight from the internet!

Python has a package manager called pip that lets you download and install extra libraries. MicroPython has its own version called upip. Once your Pico W is connected to WiFi, you can use upip to download libraries directly to the device.

This is very useful in a classroom. Each time you get a new Pico W, you can run one program to install all the libraries you need. You do not need to copy files from your PC.

Installing UPIP From Thonny

You need to install upip itself before you can use it. Use Thonny's package manager to do this.

1. Open Thonny.
2. Go to the Tools menu and click Manage Packages....
3. Type upip in the search box.
4. Click the Search on PyPI button.

1. Click on the first result: micropython-upip.

1. Click Install to add it to your Pico W.

Key Idea

PyPI (the Python Package Index) is a huge library of free Python packages. upip connects your Pico W to PyPI and downloads exactly what you need — just like an app store for your microcontroller!

Installing a Package with UPIP

This program connects to WiFi and then uses upip to install a test library. The library installed here is micropython-pystone_lowmem, a simple CPU speed test. You can replace it with any MicroPython-compatible package.

Make sure you have a secrets.py file set up from the Connecting to WiFi lab first.

import upip                                    # the MicroPython package installer
import network                                 # WiFi library
import secrets                                 # your network name and password
from utime import sleep, ticks_ms, ticks_diff  # timing functions

print('Connecting to WiFi Network Name:', secrets.SSID)
wlan = network.WLAN(network.STA_IF)           # create WiFi object in station mode
wlan.active(True)                             # power on the WiFi chip

start = ticks_ms()  # start a timer to measure connection time

if not wlan.isconnected():
    wlan.connect(secrets.SSID, secrets.PASSWORD)  # try to connect
    print("Waiting for connection...")
    counter = 0
    while not wlan.isconnected():   # keep checking until we connect
        sleep(1)                    # wait one second between checks
        counter += 1
        print(counter, '.', sep='', end='')  # show progress dots

delta = ticks_diff(ticks_ms(), start)  # calculate connection time
print("Connect Time:", delta)          # show how long it took to connect

start = ticks_ms()  # restart the timer for the download

# change this package name to install a different library
upip.install("micropython-pystone_lowmem")

print("Download Time:", ticks_diff(ticks_ms(), start), "milliseconds")  # show download time

What each line does:

1. import upip — loads the package installer
2. upip.install("micropython-pystone_lowmem") — downloads and installs the named package to /lib/ on your Pico W
3. ticks_ms() before and after — measures how many milliseconds the download takes

Expected output:

Connecting to WiFi Network Name: MY_NETWORK_NAME
Waiting for connection...
1.2.3.4.Connect Time: 4641
Installing to: /lib/
Warning: micropython.org SSL certificate is not validated
Installing micropython-pystone_lowmem 3.4.2.post4 from https://micropython.org/pi/pystone_lowmem/pystone_lowmem-3.4.2.post4.tar.gz
Download Time: 4918 milliseconds

The library is now saved on your Pico W. You can use it every time you restart without downloading it again.

Monty's Tip

To install a different library, just change the package name in the upip.install() line. Search for micropython- packages on PyPI to find what is available.

Testing Your Newly Installed Library

After installing, test the new library to make sure it works.

import pystone_lowmem     # import the library we just installed
pystone_lowmem.main()     # run its built-in test function

Expected output:

Pystone(1.2) time for 500 passes = 410ms
This machine benchmarks at 1219 pystones/second

This confirms the library installed correctly. The numbers measure how fast your Pico W's processor runs.

Getting UPIP Help

You can ask upip to explain itself:

import upip
upip.help()  # print instructions for using upip

Output:

upip - Simple PyPI package manager for MicroPython
Usage: micropython -m upip install [-p <path>] <package>... | -r <requirements.txt>
import upip; upip.install(package_or_list, [<path>])

If <path> isn't given, packages will be installed to sys.path[1], or
sys.path[2] if the former is .frozen (path can be set from MICROPYPATH
environment variable if supported).
Default install path: /lib

Note: only MicroPython packages (usually, named micropython-*) are supported
for installation, upip does not support arbitrary code in setup.py.

Great Work!

Your Pico W can now download and install new libraries from the internet! This makes it easy to add new features to any project.