Barcodes on Blog | Jonas Neubert

The Best Python Packages for Reading Barcodes

Fri, 30 Sep 2022 00:00:00 +0000

Three years ago I published a blog post on how to generate barcodes using Python. It’s one of the most visited posts on the blog! Occasionally a reader emails to ask: “But what if I want to read/decode/scan¹ a barcode, not write it?”

Here is the answer:

Don’t use Python for Barcode Decoding!

You really shouldn’t be using pure Python to decode barcodes from images or videos or, worse, from camera streams.

The Best Python Packages for Generating Barcodes

Wed, 23 Jan 2019 00:00:00 +0000

Barcodes are a cheap and ubiquitous way to add machine-readable information to an object. I think of barcodes as the real-world equivalent of browser cookies: For example, when you arrive at airport departures, the airline hands you a boarding pass with a barcode (the cookie). From that point onward you’re asked to show your barcode at every interaction: at security, the duty-free shop, and the boarding gate. And just like the information stored in browser cookies, the information in barcodes isn’t in plain sight but easily made visible.

One simple trick for USB-to-Serial on MacOS X

Tue, 07 Mar 2017 00:00:00 +0000

Call me a Luddite if you wish, but I lament the lack of serial ports in modern laptops.

My relationship with USB-to-Serial cables has been one of disappointments, crashed computers, and garbled data. The one I pulled out of a drawer this week randomly flipped the most significant bit of every character. How do I know this? Because I wasted three long nights debugging the problem.

But I’m a changed person now because I learned this one amazing trick for making USB-to-Serial just work on macOS:

MS3 Adapter for Serial Port and Power

Mon, 06 Mar 2017 00:00:00 +0000

In last week’s post about barcode readers I mentioned that I purchased an MS3 from Microscan for my PyCon demo. What I had forgotten from last time I worked with the MS3 is that the pin-out of cable attached to the barcode reader is not just a DB9 (nine pin) serial port connector but a DB15 (VGA style) plug. Those extra pins are used for sending power to the device and to accommodate a few extra features, namely trigger and reset inputs.

Intro to Barcode Readers

Sun, 26 Feb 2017 00:00:00 +0000

If you read last week’s blog post you already know that I’ve got three months to put together a physical demo for a PyCon talk about factory automation. This post is the first in a series of progress updates.

In robotics and automation, the smallest realistic demo has three parts: Sensing, control, and actuation. I spent Week 1 selecting and bargain hunting for an industrial barcode reader to cover the sensing part of the demo. As I went along I wrote up my notes as an “Introduction to Barcode Readers”; if you only want to know what I ended up buying, scroll down to the end!