Vial - A Micropython Webserver

Vial is a tiny web server to help hobbyists and developers who are using micropython to develop their own projects. The project is so named as a nod to Flask.

Scope

The current status of this project is alpha. It is currently designed to target the nodemcu chip, and only the core micropython project. However, this will encompass other libraries that can use micropython, and thereby, circuitpython.

Example usage

• To make pin 2 output and switch it on, send get request to http://*ip-address-of-nodemcu*/write/2/on
• To read from pin 2 with PULL_UP, send get request to http://*ip-address-of-nodemcu*/read/2?pull=up
• To measure from a sensor, http://*ip-address-of-nodemcu*/measure/2?type=dht (Returns two number separated by a comma)

Instructions

• Connect to nodemcu using picocom or micropython webrepl command line tool.
• After nodemcu boots up, it will run boot.py followed by main.py
• You can send files to nodemcu as well using webrepl.

Querying Sensors

A sample query to retrieve the temperature for all onewire ds18b20 sensors connected to pin 4:

GET /measure/4?type=ds18b20

Response:
{
    'temperatures': [
        [
            {
                'id': '0xc30316b1c398ff28',
                'temperature': 28.6875
            },
            {
                'id': '0xf70024984322ef28',
                'temperature': 27.9375
            },
            {
                'id': '0x65000e98431b8f28',
                'temperature': 28.875
            },
            {
                'id': '0x8000219843054328',
                'temperature': 28.1875
            },
            {
                'id': '0x2f00219843053228',
                'temperature': 27.25
            }]
        ],
    'unit': 'celsius'
}

Features

• Querying/changing state of GPIO pins using an API.
• Allowing new routes using @app.route, similar to Flask.

Bonus

• The boot.py allows configuration of the WiFi accesspoint and the connection to an external wifi through a json.

TODO

• Rewrite the library so it is pip-installable.
• Write tests.
• Write sphinx docs.
• Connect to TravisCI.
• Move ownership to the vial-microserver team.

Contributors

• Vinay Keerthi
• Najeem Muhammed