micropython-samples/PICOWEB.md

1. Running Picoweb on hardware devices

This has regularly caused dificulty on the forum.

The target hardware is assumed to be running official MicroPython firmware. This has now been tested with a daily build of official firmware which now includes uasyncio V3. It is therefore compatible with official uasyncio V2 and V3.

This repo aims to clarify the installation process. Paul Sokolovsky's Picoweb code is unchanged. The demos are trivially changed to use IP '0.0.0.0' and port 80.

The Picoweb version in this repo is no longer current, and subsequent versions are no longer compatible with official firmware. See Picoweb versions if you want to run a version newer than that supplied here.

Note that the ESP8266 requires the use of frozen bytecode: see ESP8266 for installation instructions.

On other platfroms two ways of installing Picoweb are available: copying this directory to the target or using upip. To use upip you should ensure your firmware is V1.11 or later; your target will also require an internet connection. Both methods require the following preliminaries.

1.1 Preliminary steps

1.1.1 Clone this repo to your PC

From a suitable destination directory issue

git clone https://github.com/peterhinch/micropython-samples

1.1.2 Establish uasyncio status

Determine whether your target has uasyncio already installed. At the REPL issue:

>>> import uasyncio
>>>

If this throws an ImportError, uasyncio is not installed.

1.2 Installing using upip

Copy the picoweb subdirectory of this repo's PicoWeb directory, with its contents, to the target. If using rshell to connect to a Pyboard D this would be done from the PicoWeb directory with:

/my/tree/PicoWeb> cp -r picoweb/ /flash

Ensure your target is connected to the internet. Then perform the following steps. The first step may be omitted if uasyncio is already installed.

upip.install('micropython-uasyncio')
upip.install('micropython-ulogging')
upip.install('micropython-pkg_resources')
upip.install('utemplate')

1.3 Installing by copying this archive

Copy the contents of the PicoWeb directory (including subdirectories) to the target. If using rshell on an ESP32 change to this directory, at the rshell prompt issue

/my/tree/PicoWeb> rsync . /pyboard

This may take some time: 1 minute here on ESP32.

If uasyncio was already installed, the corrsponding directory on the target may be removed.

2. Running Picoweb

At the REPL connect to the network and determine your IP address

>>> import network
>>> w = network.WLAN()
>>> w.ifconfig()

issue

>>> from picoweb import example_webapp

or

>>> from picoweb import example_webapp2

Then point your browser at the IP address determined above.

3. ESP8266

RAM limitations require the use of frozen bytecode, and getting the examples running is a little more involved. Create a directory on your PC and copy the contents of this directory to it. Then add the files inisetup.py, _boot.py and flashbdev.py which may be found in the MicroPython source tree under ports/esp8266/modules. You may also want to add a custom connect module to simplify connection to your WiFi. Then build the firmware. The script I used was

#! /bin/bash

# Test picoweb on ESP8266

DIRECTORY='/home/adminpete/temp/picoweb'

cd /mnt/qnap2/data/Projects/MicroPython/micropython/ports/esp8266

make clean
esptool.py  --port /dev/ttyUSB0 erase_flash

if make -j 8 FROZEN_MPY_DIR=$DIRECTORY
then
    sleep 1
    esptool.py --port /dev/ttyUSB0 --baud 115200 write_flash --flash_size=detect -fm dio 0 build/firmware-combined.bin
    sleep 4
    rshell -p /dev/ttyUSB0 --buffer-size=30 --editor nano
else
    echo Build failure
fi

For the demos you will need to make the example_webapp.py source file and squares.tpl accessible in the filesystem. The following rshell commands, executed from this directory or the one created above, will make these available.

path/to/repo> mkdir /pyboard/picoweb
path/to/repo> mkdir /pyboard/picoweb/templates
path/to/repo> cp picoweb/example_webapp.py /pyboard/picoweb/
path/to/repo> cp picoweb/templates/squares.tpl /pyboard/picoweb/templates/

4. Documentation and further examples

See the PicoWeb docs

Note that to run these demos on platforms other than the Unix build you may want to change IP and port as above.

5. Picoweb versions

At the time of writing (Sept 2019) Paul Sokolovsky has released an update to support Unicode strings. This is incompatible with official firmware. The difference is small and easily fixed, however it is likely that future versions will acquire further incompatibilities. I do not plan to maintain a compatible Picoweb-copy fork; hopefully someone will accept this task.

The issues are discussed in this forum thread.

Options are:

1. Use the version in this repo.
2. Use the latest version and adapt it.
3. Use the Pycopy firmware (requires compilation).
4. Abandon Picoweb and use an alternative web framework.

These are discussed in detail in the above forum thread.