python

464 Articles

ChatGPT Makes A 3D Model: The Secret Ingredient? Much Patience

May 4, 2023 by 44 Comments

ChatGPT is an AI large language model (LLM) which specializes in conversation. While using it, [Gil Meiri] discovered that one way to create models in FreeCAD is with Python scripting, and ChatGPT could be encouraged to create a 3D model of a plane in FreeCAD by expressing the model as a script. The result is just a basic plane shape, and it certainly took a lot of guidance on [Gil]’s part to make it happen, but it’s not bad for a tool that can’t see what it is doing.

The first step was getting ChatGPT to create code for a 10 mm cube, and plug that in FreeCAD to see the results. After that basic workflow was shown to work, [Gil] asked it to create a simple airplane shape. The resulting code had objects for wing, fuselage, and tail, but that’s about all that could be said because the result was almost — but not quite — completely unlike a plane. Not an encouraging start, but at least the basic building blocks were there. Continue reading “ChatGPT Makes A 3D Model: The Secret Ingredient? Much Patience” →

Timeframe: The Little Desk Calendar That Could

April 16, 2023 by 7 Comments

Usually, the problem comes before the solution, but for [Stavros], the opposite happened. A 4.7″ E-Ink screen with integrated battery management and ESP32 caught his eye, and he bought it and started thinking about what he wanted to do with it. The Timeframe is a sleek desk calendar based around the integrated e-ink screen.

[Stavros] found the device’s MicroPython support was a little lackluster, and often failed to draw. He found a Platform.io project that used an older but modified library for driving the e-ink display which worked quite well. However, the older library didn’t support portrait orientation or other niceties. Rather than try and create something complex in C, he moved the complexity to a server environment he knew more about. With the help of CoPilot, he got some code that would wake up the ESP32 every half hour, download an image from a server, and then display it. A Python script uses a headless browser to visit Google Calendar, resize the window, take a screenshot, and then upload it.

The hardest part of the exercise was getting authentication with Google working reliably. A white sleek 3D printed case wraps the whole affair in an aesthetically pleasing shell. So far, this has been a great story of someone building something for themselves and using their strengths. Where’s the hack?

The hack comes when [Stavros] tried squeezing his calendar into a case that was too tight and cracked the screen. Suddenly a large portion of the screen wouldn’t draw. He turned what was broken into something new by mapping out the area that didn’t draw and converting the Python to draw weather information with Pillow rather than screenshot a webpage: clever reuse and a way to make good out of a bad accident.

The code is up on GitLab, and the 3D files for the case are available on Printables. You can also find the project on Hackaday.io, as it was an entry into our recently concluded Low-Power Contest. Unfortunately, while the Timeframe is pretty power efficient, it doesn’t last as long as this calendar with a 50-year battery life.

Wolverine Gives Your Python Scripts The Ability To Self-Heal

April 9, 2023 by 38 Comments

[BioBootloader] combined Python and a hefty dose of of AI for a fascinating proof of concept: self-healing Python scripts. He shows things working in a video, embedded below the break, but we’ll also describe what happens right here.

The demo Python script is a simple calculator that works from the command line, and [BioBootloader] introduces a few bugs to it. He misspells a variable used as a return value, and deletes the subtract_numbers(a, b) function entirely. Running this script by itself simply crashes, but using Wolverine on it has a very different outcome.

In a short time, error messages are analyzed, changes proposed, those same changes applied, and the script re-run.

Wolverine is a wrapper that runs the buggy script, captures any error messages, then sends those errors to GPT-4 to ask it what it thinks went wrong with the code. In the demo, GPT-4 correctly identifies the two bugs (even though only one of them directly led to the crash) but that’s not all! Wolverine actually applies the proposed changes to the buggy script, and re-runs it. This time around there is still an error… because GPT-4’s previous changes included an out of scope return statement. No problem, because Wolverine once again consults with GPT-4, creates and formats a change, applies it, and re-runs the modified script. This time the script runs successfully and Wolverine’s work is done.

LLMs (Large Language Models) like GPT-4 are “programmed” in natural language, and these instructions are referred to as prompts. A large chunk of what Wolverine does is thanks to a carefully-written prompt, and you can read it here to gain some insight into the process. Don’t forget to watch the video demonstration just below if you want to see it all in action.

While AI coding capabilities definitely have their limitations, some of the questions it raises are becoming more urgent. Heck, consider that GPT-4 is barely even four weeks old at this writing.

Continue reading “Wolverine Gives Your Python Scripts The Ability To Self-Heal” →

Pi Microcontroller Still Runs A Webserver

April 7, 2023 by 14 Comments

At first glance, the Raspberry Pi Pico might seem like a bit of a black sheep when compared to the other offerings from the Raspberry Pi Foundation. While most of the rest of their lineup can run Linux environments with full desktops, the Pico is largely limited to microcontroller duties in exchange for much smaller price tags and footprints. But that doesn’t mean it can’t be coerced into doing some of the things we might want a mainline Pi to do, like run a web server.

The project can run a static web page simply by providing the Pico with the project code available on the GitHub page and the HTML that you’d like the Pico to serve. It can be more than a static web page though, as it is also capable of running Python commands through the web interface as well. The server can pass commands from the web server and back as well, allowing for control of various projects though a browser interface. In theory this could be much simpler than building a physical user interface for a project instead by offloading all of this control onto the web server instead.

The project not only supports the RP2040-based Raspberry Pi Pico but can also be implemented on other WiFi-enabled microcontroller boards like the ESP8266 and ESP32. Having something like this on hand could greatly streamline smaller projects without having to reach for a more powerful (and more expensive) single-board computer like a Pi 3 or 4. We’ve seen some other builds on these boards capable of not only running HTML and CSS renderers, but supporting some image formats as well.

Continue reading “Pi Microcontroller Still Runs A Webserver” →

Bus Stop Bloom Filter

March 27, 2023 by 19 Comments

Imagine you’re sitting on a nice bench, the sun shines warmly, and a bus pulls up. You’re headed to Stendal from Osnabrück, how can you tell if you should get on that bus? [Julian Vanecek] is trying to turn that from an O(n) problem to an O(1) one with a Bloom filter right at the bus stop.

In [Julian’s] sample code, each stop is a 3-bit number that can be encoded into a 192-bit array. Your ticket is just that 3-bit number encoded, so you can look at the graphic on the side of the incoming bus, match it against your ticket, and hop on. Gone are the days of waiting for the little LED screen to cycle through all the stops, waiting for yours to come up. Your ticket should have just a few boxes filled in so it is relatively quick to search against the bus’s graphic.

Of course, there is a potential for a false positive rate. [Julian] points out that this can be tuned to prevent errors and has achieved a < 0.5% false positive rate using the Deutsche Bahn bus system. The code is written in Python and available on GitHub. Perhaps buses could have a large flip-dop display on the side, to adjust to show which stops they’re headed to next. Additionally, it doesn’t encode which stops are next, just which stops the bus will eventually go to.

In the video after the break, [Julian] explains how the system works. Whether it would be ultimately adopted is somewhat beside the point. We love the seeing people re-imagining ideas and trying to apply new techniques to improve the things around them.

Continue reading “Bus Stop Bloom Filter” →

OpenSPICE: A Portable Python Circuit Simulator

February 14, 2023 by 22 Comments

[Roman Parise] and [Georgios Is. Detorakis] have created OpenSPICE a fork of the PySpice project, adding a new simulation engine written entirely in Python. This enables the same PySpice simulations to be executed on any platform that runs python (which we reckon is quite a few!) whilst leveraging the full power of the python infrastructure. Since it is a fork — for supported platforms — you can also run your simulations upon Ngspice as well as Xyce, giving options for scaling up to larger systems when required, but importantly without having to recreate your circuit from scratch.

The OpenSPICE simulator first converts the parsed netlist into a set of data structures that represent the equations describing the various parts of the system. These are then in turn passed along the scipy library “optimize.root” function which solves the system, generating a list of branch currents and node voltages. The output of the simulation is a numpy array, which can be further processed and visualized with the mathplotlib library. All pretty standard stuff in python circles. Since this is based upon PySpice, it’s also possible to use KiCAD netlists, so you have a nice way to enter those schematics. We’ve not dug into this much yet, but support for the vast libraries of spice models out there in circulation would be high up on our wish list if it already can’t handle this. This scribe will most definitely be checking this out, as LTSpice whilst good, is a bit of a pain to use and does lack the power of a Python backend!

Continue reading “OpenSPICE: A Portable Python Circuit Simulator” →

Hacking The Python For Loop

February 5, 2023 by 33 Comments

In the early days of C, you’d occasionally see someone — probably a former Pascal programmer — write something like this:

#define BEGIN {
#define END }

This would usually initiate complaints about abusing the preprocessor and generally being anti-C. Surely no modern language would permit such things, right? Perhaps not. Consider [Tushar Sadhwani] who wanted to create a classic C-style for loop inside of Python. He did it, and the journey is perhaps more interesting than the result.

First, you can’t just transport straight C for loops into Python. There has to be some concession to Python syntax. The initial attempt was clever but not clever enough. However, the disassembly of the Python code was telling. The second attempt, however, was particularly interesting.

That attempt used an odd feature to examine the interpreter’s tree structure for the code and then modify it. This is sort of like a very painful C preprocessor but more powerful. That version works although it is pretty convoluted.

Ironically, [Tushar] then set up a third attempt after seeing code that tries to replace Python indentation with braces using a codec. In Python-speak, a codec lets you convert different text encodings. However, you can do other things than text encoding conversion. This is closest in spirit to the C preprocessor method. You can wade through the source code ahead of processing and make whichever changes you see fit.

Is any of this really useful? Probably not as it is. But you never know when you might need to do something exotic and one of these techniques could save the day. You probably couldn’t get away with some of this on MicroPython, of course. Your mileage may vary depending on where you find your Python running — like the Web.