Merry Christmas from Rossum!

This simple project demonstrates how Rossum can be used not only as a data extraction tool but also as an integration between various tools and technologies.

We want to prepare a simple document, which Rossum should be able to extract message from, and send it to our display device at home using its awesome hook mechanism.

Overview

We're gonna build a simple stack using a various option of technologies

• Wemos D1 mini as a server displaying message on a display
• SSD1306 OLED display to display our message
• fast-api server as a bridge between ngrok and our local display
• ngrok to be able to access our local server from the internet
• Rossum to extract data from .docx file (yes, Rossum is able to process MS Word and Excel documents as well 🚀) and display message on our display using its amazing hook functions

How to

Wemos D1 mini

First we need to prepare our esp-8266 to be able to display our message.

• we will need a Wemos D1 mini board and a SSD1306 OLED display

• we need to flash micropython firmware to our wemos d1 mini (more here)

• download the newest firmware here

• install esptool

  python3 -m pip install esptool

• erase flash of your d1 mini

  esptool.py --chip esp8266 erase_flash

• install the latest firmware

  esptool.py --port /dev/cu.usbserial-110 --baud 460800 write_flash --flash_size=detect 0 esp8266-20210902-v1.17.bin

• connection

  SSD1306	Wemos D1 mini
  GND	GND
  VCC	5V
  SCL	D1
  SDA	D2

• we need to prepare a configuration file wemos_display/configuration.py based on configuration template

  • if you're using the same display - SSD1306 you should follow

  WIFI_CREDENTIALS = {
      "ssid": "...",
      "password": "...",
      "hostname": "RossumDisplay",
  }
  
  I2C_PINS = {
      "sda": 4,  # D2
      "scl": 5,  # D1
  }
  
  DISPLAY_RESOLUTION = (128, 64)

  fill in WIFI_CREDENTIALS based on your configuration

• boot.py is run on d1 startup and creates local Wi-Fi connection

• display.py is a simple module handling our display

• main.py defines a simple http server listening on 80 port for any http GET request with ?text=... in its path

• the simplest way how to load .py files to d1 mini is using PyCharm's micropython plugin

Fast-Api local server

Since most of people does not have a private IP we need to create another http server that will be made public using ngrok.com and will simply call our d1 mini

• requirements.txt defines the only two dependencies our simple server has (fastapi and uvicorn)
• main.py defines a light-weight Fast-API server that accepts HTTP POST request and converts it to HTTP GET request sent to our d1 mini
• to start the server simply run

  python3 -m pip install -r requirements.txt
  uvicorn main:app --reload
  

Ngrok to make our FastApi server public

• download ngrok
• run ngrok http 8000 to make our fast-api app public (make note of the displayed URL - in our case https://82dd-2a00-1028-8392-1dea-d875-b857-3121-5883.ngrok.io)

Prepare Rossum python function extension

• visit rossum-elis
• update queue schema according to schema.json (it creates 3 string fields: address (url of our ngrok server), local_address (local address of our d1 mini server), text (text message to display on our display))
• create function extension attached to the queue with updated schema
• set the trigger event document content - export
• update function code according to function.py

Prepare MS Word document

• create a merry_christmas.docx file with following fields
  • address (url of our ngrok server)
  • local address (local address of our d1 mini server)
  • text (text message to display on our display)

Let the magic happen in Rossum

• upload the MS Word file to your Rossum queue
• click on your Christmas document
• make sure the bounding boxes cover your texts
• click the Confirm button
• the document gets exported
• you should see the message on your display! 🎉

3D printed enclosure

Now that we have working prototype we can use 3D printer and create a case for our device There are several cases on thingiverse we could use e.g. this one

• solder wires
• print case
• put it all together