What is this all about?

Got a cheap USB receipt printer?

You probably noticed how difficult can it be to interface with it and print anything useful... :/

• ESC/POS standard is messy and convoluted
• The existing customer-oriented software is largely low-quality or paid / subscription-based
• Open-source solutions are primarily made for devs and are not approachable for avg consumer

So what do we do about it?

• Leverage existing open-source solutions implementing ESC/POS commands
• Connect the printer via USB to Raspberry Pi Zero W
• Expose a POST endpoint to send print jobs to the printer
• Provide a way to print HTML canvas (rendered as an image) to bypass ESC/POS
• Build a number of presets to simplify generating shopping lists, tables and other common things

Getting started

• Install Node.js (ARM6 unofficial build for RPi0W)

curl -O https://unofficial-builds.nodejs.org/download/release/v${NODE_VER}/node-v${NODE_VER}-linux-armv6l.tar.xz
tar -xf node-v${NODE_VER}-linux-armv6l.tar.xz

• Clone the repository

git clone https://github.com/dmitryfd/receipt-please.git && cd receipt-please

• Install the dependencies

sudo apt-get install libudev-dev

CXXFLAGS="--std=c++14" npm install

• Modify the config as needed

vim config.js

• Create a writeable uploads directory

mkdir uploads
chmod 777 uploads

• Ensure permissions for the USB device

echo "SUBSYSTEM==\"usb\", ATTR{idVendor}==\"0416\", ATTR{idProduct}==\"5011\", MODE=\"0666\"" | sudo tee /etc/udev/rules.d/40-receiptplease.rules > /dev/null

sudo udevadm control --reload-rules

sudo udevadm trigger

• Run

node index.js

What is your hardware setup?

• Raspberry Pi Zero W running (unofficial) Node LTS

  • Connected to Internet via WiFi

• ZJ-5802 printer connected to Pi via USB

  • Bluetooth is also supported, but causes gaps in the images due to insufficient baud rate
  • You could include escpos-bluetooth-patch to set up such an adapter in lieu of USB

• Any device in the local network can navigate to http://raspberrypi:3000 and submit prints

Next steps

• Add web-based functionality

  • Weather / stocks / quotes / recipes / ...

• Build a simple Android app exposing POST endpoint as a share target

• Allow to render the canvas on the server side

  • Using node-canvas library

• Allow to take advantage of other ESC/POS commands

  • For the cases where the "default" text styles are preferred
  • Can be easily built-in using capabilities of node-escpos