receiptprinter

This is a node app and pile of utilities for hooking a thermal receipt printer up to a website, Azure queue, Google Home, and more. When you've got the receipt printer hooked up, you can use it for creating lists, creating task sheets, or just printing text receipts.

Hardware

The canonical hardware setup is a raspberry pi running the source in this repo, and an Epson TM-T20II attached over USB. The Pi doesn't have to be very powerful -- any modern Pi from the last five years should work. The TM-T20II can be found on eBay for around $100 and uses standard thermal printer paper, which is extremely inexpensive.

Other printers may work but I've only tried the TM-T20II.

"Architecture" lol

This project includes a single Node.js app that runs on a raspi and sends properly-formatted text messages to a USB-connected Epson printer.

There are two ways for the Node.js app to get your text strings to print:

1. Direct (enabled by default): If you're able to expose the Pi to the internet (and are comfortable doing so), it can expose a webpage and HTTP POST endpoint directly. Just point a browser to the webpage or an IFTTT integration to the endpoint.
2. Remote (enabled with connection string): If you're unable to expose the Pi directly, or feel safer with some indirection, you can run an included Node app on an internet-facing website, which adds text items to print into a queue, which is monitored by the Pi.

In addition to the core printing functionality, the repo includes some useful utilities:

• An init.d script to start the printer code on boot
• A "quotes" sample with example contents and curl string to print memorable quotes
• Tools to restart the raspi and reload the printer's code from git

Setup

1. Clone this project into a user directory on your raspi
2. Edit receipt.js, init.d/receipt.sh and replace any ALL_CAPS text with your own
3. npm install
4. Copy init.d/receipt.sh to /etc/init.d and link in from init levels
5. If using remote mode,
   1. Log in to https://portal.azure.com and create an Azure Storage account, and get your connection string
   2. Rename remotesite/QUEUENAME to your own name (e.g. remotesite/home)
   3. Edit remotesite/app.js and replace an ALL_CAPS text with your own
   4. npm install
   5. Publish everything in the remotesite/ directory to your internet-facing website
6. If you want reload/restart functionality, cd into restart and make restart
   • You may also need to edit reload.sh to make it work

Routes

Path	Description
GET http://PI_HOSTNAME/receipt	Webpage with text form to print
POST http://PI_HOSTNAME/receipt	Post text to print
POST http://PI_HOSTNAME/receipt/ifttt	Endpoint for posting text from IFTTT to print
POST http://PI_HOSTNAME/receipt/today	Print receipt with today's date formatted across a bunch of lines
POST http://PI_HOSTNAME/receipt/quote	Load a random quote from quotes/quotes.txt and print it
POST http://PI_HOSTNAME/receipt/reload	git pull and restart pi
POST http://PI_HOSTNAME/receipt/restart	restart pi
GET http://REMOTE_SITE/receipt/QUEUENAME	Webpage with text form to enqueue to QUEUENAME
POST http://REMOTE_SITE/receipt/queue/QUEUENAME	Post text to enqueue to QUEUENAME
POST http://REMOTE_SITE/receipt/queue/QUEUENAME/ifttt	Endpoint for posting text from IFTTT to print

Manifest

File	Description
init.d/recipt.sh	init.d script to start Node.js app
restart/	Utility to restart the host OS remotely, if you want that
remotesite/	Standalone website to run on cloud host to queue up text snips for non-NAT printer
remotesite/app.js	Node.js server app
remotesite/web.config	IISNode for running on Azure Web Apps
remotesite/QUEUENAME	Webpage to post to queue called QUEUENAME
web/	Webpage exposed by Node.js app to accept text to print
quotes/	Example illustrating how to print quotes with curl
receipt.js	Node.js app to print to pi
reload.sh	Script to reload source code from git and restart for headless operation