[PYTHON] Display the weather forecast on M5Stack + Google Cloud Platform

My name is Niamugi and I am in charge of the 4th day of IoTLT Advent Calendar 2019. "Displaying the weather forecast on M5Stack" is a very solid content, but I would like to introduce it because it has a nice and versatile mechanism. ** It is popular with my family, and I am happy that it is used on a daily basis. ** **

Appearance

Displays the weather forecast for the last 3 days. I had my eldest son write the weather mark.

It will be displayed like this.

• Actually it takes about 30 seconds ...

How it works

The weather forecast image is divided into "** generate " and " acquire **".

1. Periodically run the "Weather Forecast Image Generation Function" on Google Cloud Platform (GCP) Cloud Scheduler.
2. Create a weather forecast image with Cloud Functions on GCP and save it to Google Drive.
3. Execute the "function to get the image of the weather forecast" in the http request from M5Stack to get the image.

(Details) About image generation

I will enumerate the points.

Get the weather forecast

Data is obtained by accessing Weather Forecast of Japan Meteorological Agency.

Handle files with Cloud Functions

If you want Cloud Functions running on the cloud to work with your files, you can save them in the / tmp folder. In other words, by saving the file acquired by Google Drive in the / tmp folder, you can handle the file in the same way as in the local environment.

Preparing to access Google Drive

Obtain the client ID, client secret, and refresh token required for access in advance. I wrote about this on the blog of dot studio before. [How to upload data from NefryBT to Google Drive](https://dotstud.io/blog/update-nefrybt-to-googledrive/#%E3%82%A2%E3%83%83%E3%83%97% E3% 83% AD% E3% 83% BC% E3% 83% 89% E3% 81% BE% E3% 81% A7% E3% 81% AE% E6% 89% 8B% E9% A0% 86 )Please refer to.

Operate Google Drive

• This is a fairly detailed content. We will provide some functions to access Google Drive.

Function to get the service to access Google Drive

Get the service to access Google Drive using the client ID, client secret, and refresh token. I referred to "python refresh token Google API: get credentials from update token using oauth2client.client".

def getDriveService():
    CLIENT_ID = os.getenv("drive_client_id")
    CLIENT_SECRET = os.getenv("drive_client_secret")
    REFRESH_TOKEN = os.getenv("drive_refresh_token")

    creds = client.OAuth2Credentials(
        access_token=None,
        client_id=CLIENT_ID,
        client_secret=CLIENT_SECRET,
        refresh_token=REFRESH_TOKEN,
        token_expiry=None,
        token_uri=GOOGLE_TOKEN_URI,
        user_agent=None,
        revoke_uri=None,
    )
    http = creds.authorize(httplib2.Http())

    creds.refresh(http)
    service = build("drive", "v3", credentials=creds, cache_discovery=False)
    return service

Function to search by file name and get ID

Each data in Google Drive is assigned an ID. Since data is acquired and updated by ID, it is necessary to search for the ID.

def searchID(service, mimetype, nm):
    """Find a matching ID from Drive
    """
    query = ""
    if mimetype:
        query = "mimeType='" + mimetype + "'"

    page_token = None
    while True:
        response = (
            service.files()
            .list(
                q=query,
                spaces="drive",
                fields="nextPageToken, files(id, name)",
                pageToken=page_token,
            )
            .execute()
        )

        for file in response.get("files", []):
            if file.get("name") == nm:
                return True, file.get("id")

        page_token = response.get("nextPageToken", None)
        if page_token is None:
            break

Function to get font data

Since Cloud Functions runs on the cloud, I think Japanese fonts probably won't work. (I haven't tried it) So get the font from Google Drive. The mimetype is "application / octet-stream".

def getFontFromDrive(service, fontName):
    """Get fonts from Drive and save them in tmp folder
    """
    ret, id = searchID(service, "application/octet-stream", fontName)
    if not ret:
        return None

    request = service.files().get_media(fileId=id)
    fh = io.FileIO("/tmp/" + fontName, "wb")  #File

    downloader = MediaIoBaseDownload(fh, request)
    done = False
    while done is False:
        status, done = downloader.next_chunk()

    return "/tmp/" + fontName

Function to get image data

Get the weather mark. mimetype is "image / png".

def getImageFromDrive(service, imageName):
    """Get the image from Drive and save it in the tmp folder
    """
    ret, id = searchID(service, "image/png", imageName)
    if not ret:
        return False

    request = service.files().get_media(fileId=id)
    fh = io.FileIO("/tmp/" + imageName, "wb")  #File

    downloader = MediaIoBaseDownload(fh, request)
    done = False
    while done is False:
        status, done = downloader.next_chunk()

    return True

Function to upload image data

Upload the generated weather forecast image to Google Drive.

def uploadData(service, mimetype, fromData, toData, parentsID="root"):
    """Upload to Drive
    """
    try:
        media = MediaFileUpload(fromData, mimetype=mimetype, resumable=True)
    except FileNotFoundError:
        return False

    #Search for ID and overwrite if there is applicable data.
    ret, id = searchID(service, mimetype, toData)
    if ret:
        file_metadata = {"name": toData}

        file = (
            service.files()
            .update(fileId=id, body=file_metadata, media_body=media, fields="id")
            .execute()
        )
    else:
        file_metadata = {"name": toData, "parents": [parentsID]}

        file = (
            service.files()
            .create(body=file_metadata, media_body=media, fields="id")
            .execute()
        )

    return True

A series of flows

Use the function prepared above to upload the weather forecast image to Google Drive.

def CreateImgWeather(event, context):
    """ get weatherImage and upload to drive for M5stack
    """

    # 1.Get a service to access Google Drive
    driveService = getDriveService()

    # 2.Get font
    fontPath = getFontFromDrive(driveService, "meiryo.ttc")
    if not fontPath:
        return False

    # 3.Get the weather mark
    if not getImageFromDrive(driveService, "noImage.png "):
        return False
    if not getImageFromDrive(driveService, "fine.png "):
        return False
    if not getImageFromDrive(driveService, "cloud.png "):
        return False
    if not getImageFromDrive(driveService, "rain.png "):
        return False
    if not getImageFromDrive(driveService, "snow.png "):
        return False

    # 4.Generate weather forecast image
    weatherList = getWeekWeather()
    ret = createImg(fontPath, "/tmp/imgWeather.jpeg ", weatherList)
    if not ret:
        return False

    # 5.Upload to Google Drive
    ret = uploadData(
        driveService, "image/jpeg", "/tmp/imgWeather.jpeg ", "imgWeather.jpeg "
    )
    if not ret:
        return False

    return True

(Details) About image acquisition

M5Stack side

For details, refer to Source.

Access the Cloud Functions functions with an http POST request. This is also dotstudio's "Throw a request via HTTP communication" I used it as a reference.

[hostname] = "[Project name].cloudfunctions.net"
[Function name] = "getDriveImage_M5stack";
[port number] = 443;
      
POST /[Function name] HTTP/1.1
Host: [hostname]:[port number]
Connection: close
Content-Type: application/json;charset=utf-8
Content-Length:  + [Size of json data to post]

[Json data to post]

Make the following request in json data format.

{
  "drive" : {
    "img" : "[file name]",
    "trim" : "[Split number]"
  }
}

Due to the amount of data that can be acquired at one time, it is divided into 8 parts. Therefore, it makes a POST request 8 times.

Cloud Functions side

Get the weather forecast image according to the POST request from M5Stack. Then, it returns the binary data divided into 8 parts.

I will put the sauce on it.

import sys
import os
import io
from io import BytesIO
import numpy as np
from PIL import Image

import httplib2
from googleapiclient.discovery import build
from oauth2client import client, GOOGLE_TOKEN_URI
from apiclient.http import MediaIoBaseDownload


def getDriveService():
    ~Same as image generation~

def searchID(service, mimetype, nm):
    ~Same as image generation~


def downloadData(mimetype, data):
    #Get a service to access Google Drive
    drive_service = getDriveService()

    #Search for ID
    ret, id = searchID(drive_service, mimetype, data)
    if not ret:
        return False, None

    #Search for weather forecast images
    request = drive_service.files().get_media(fileId=id)
    fh = io.BytesIO()
    downloader = MediaIoBaseDownload(fh, request)
    done = False
    while done is False:
        status, done = downloader.next_chunk()
    
    return True, fh.getvalue()


def devideImage_M5stack(imgBinary, _trim):
    """Split the image for M5Stack. The return value is image data
    """
    imgNumpy = 0x00

    #Confirmation of input data
    if _trim.isnumeric():
        trimPos = int(_trim)
        if trimPos <= 0 or trimPos > 8:
            return False
    else:
        return False

    #Image split
    # 1 2 3 4
    # 5 6 7 8
    Trim = [
        (0, 0, 80, 120),
        (80, 0, 160, 120),
        (160, 0, 240, 120),
        (240, 0, 320, 120),
        (0, 120, 80, 240),
        (80, 120, 160, 240),
        (160, 120, 240, 240),
        (240, 120, 320, 240),
    ]

    #PIL image<-Binary data
    img_pil = Image.open(BytesIO(imgBinary))

    #trimming
    im_crop = img_pil.crop(Trim[trimPos - 1])

    #numpy array(RGBA) <-PIL image
    imgNumpy = np.asarray(im_crop)

    return True, imgNumpy


def getBinary(img):
    """Convert images to binary data
    """
    ret = ""
    pilImg = Image.fromarray(np.uint8(img))
    output = io.BytesIO()
    pilImg.save(output, format="JPEG")
    ret = output.getvalue()

    return ret


def getDriveImg_Binary(imgName, trim):
    """Get the image saved in googleDrive. The return value is binary data.
    """

    img = 0x00

    #Image from Drive(Binary data)Get
    ret, imgBinary = downloadData("image/jpeg", imgName)
    if not ret:
        print("...error")
        return ""

    print(ret, len(imgBinary))

    #Split the image
    #* For M5Stack only
    if trim is not None:
        isGet, img = devideImage_M5stack(imgBinary, trim)
        if not isGet:
            return ""

        #Convert to binary data
        imgBinary = getBinary(img)

    return imgBinary


def getDriveImage_M5stack(request):
    imgName = ""
    trim = "0"

    #Request data(JSON)Convert
    request_json = request.get_json()

    #Get access information to Google Drive
    if request_json and "drive" in request_json:
        imgName = request_json["drive"]["img"]
        trim = request_json["drive"]["trim"]
    else:
        return ""

    #Get a trimmed weather forecast image
    ret = getDriveImg_Binary(imgName, trim)

    return ret

application

The good thing about this mechanism is that "** You can display it on M5Stack if you prepare an image **". In other words, it is not limited to weather forecasts, but can handle anything such as schedules and tasks. On the M5Stack side, just set the image name to be acquired. Also, since the image is generated outside of M5Stack, there is no need to touch the M5Stack program when you want to modify the image.

The following is the pattern that displayed the Google calendar. (The schedule is mosaic)

Summary

Now that we have created an image display system that matches M5Stack, we have come to think of some application patterns. The display of M5Stack is just the right size for the table, so I would like to use it in various ways.

I hope it will be helpful for you. See you soon.

reference

[How to upload data from NefryBT to Google Drive](https://dotstud.io/blog/update-nefrybt-to-googledrive/#%E3%82%A2%E3%83%83%E3%83%97% E3% 83% AD% E3% 83% BC% E3% 83% 89% E3% 81% BE% E3% 81% A7% E3% 81% AE% E6% 89% 8B% E9% A0% 86 ) python refresh token Google API: use oauth2client.client to get credentials from update token Throw a request via HTTP communication