library

40 Articles

Digital Library Of Amateur Radio And Communications Is A Treasure Trove

February 20, 2023 by 23 Comments

Having a big bookshelf of ham radio books and magazines used to be a point of bragging right for hams. These days, you are more likely to just browse the internet for information. But you can still have, virtually, that big shelf of old ham books, thanks to the DLARC — the digital library of Amateur Radio and Communications.

A grant from a private foundation has enable the Internet Archive to scan and index a trove of ham radio publications, including the old Callbooks, 73 Magazine, several ham radio group’s newsletters from around the globe, Radio Craft, and manuals from Icom, Kenwood, Yaesu, and others.

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The Pi Pico board on top of a white box with an Ethernet jack, with a sensor module plugged onto the Pico's pin headers. A black MicroUSB and a green Ethernet cable are connected to this device.

An Elegant Ethernet Library For Your Next RP2040 Project

August 27, 2022 by 17 Comments

A few days ago we covered a project that brought Ethernet connectivity to the Raspberry Pi Pico using little more than some twisted pair and a RJ-45 connector. It was a neat trick, but not exactly ready for widespread adoption. Looking to improve on things a bit, [tvlad1234] has taken that project’s code and rewritten it into a friendly library you can use with any RP2040 board.

In case you missed it, the initial demo did 10BASE-T transmission by bit-banging with the PIO, and was able to send UDP messages to devices on the wired LAN. It was an impressive accomplishment, but its code didn’t make it easy to build your project around it. This new library makes UDP messaging as easy as a printf, offloading all non-PIO-managed Ethernet signal work onto the RP2040’s second CPU core. The library even generates a random MAC address out of your flash chip’s serial number!

As a demonstration of the new library, [tvlad1234] has put together a simple Ethernet-connected temperature monitor using the BMP085 or BMP180 sensor connect over I2C. If you feel like you could use an Ethernet transmit-only sensor in your life, browsing the source code would be a great start.

Build Your Own… Whatever

July 12, 2022 by 23 Comments

You can read all about making, say, a bookshelf or bowling, but unless you’ve actually done it, you don’t really know how it works. That’s the idea behind [codecrafters-io] Build-Your-Own-X GitHub repository. It is a collection of software projects from around the Web that offer “step-by-step guides for recreating our favorite technologies from scratch.”

What can you find there? Well, how about writing your own version of Git itself? Or maybe you’d like to dive into a physics engine, blockchain code, or a text editor. Then there’s our favorite: an operating system.

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Network Time Protocol On The ESP32

May 16, 2022 by 29 Comments

Network Time Protocol (NTP) is one of the best ways to keep networked computers synchronized to the same time. It’s simple, lightweight, and not only allows computers to maintain a time standard together, but it also allows some computer manufacturers to save some money on hardware costs. The Raspberry Pi is perhaps the most well-known example of a low-cost computer without the extra expense of a real-time clock (RTC). While the Pi sets up NTP essentially automatically, other microcontrollers like the ESP32 don’t, but it is possible to configure them to use this time standard with some work.

For this project the MicroPython implementation for the ESP32 is required. MicroPython is a way of running Python code on microcontrollers or other embedded systems without all of the overhead that Python would normally require. Luckily enough, the NTP libraries are built right in so once MicroPython is running on the ESP32 it’s nearly as easy as calling the library. Of course you will have to make sure there is an internet connection, and then grab the time, sync it to the machine, and then set the timezone.

For a bonus exercise, the project’s creator [Bhavesh] suggests attempting to configure Daylight Savings Time, although this can be a surprisingly difficult problem to solve. In the meantime, there are a few other ways of installing a clock on a microcontroller like this one. An RTC module is an obvious choice, but you can also get incredibly accurate time by using a GPS module as well.

Mindblowing Graphics From An ATtiny85

April 12, 2022 by 24 Comments

[Görg Pflug] wrote in with his really nice graphics library. It’s got multiple layers, two text consoles, greyscale, internal halftoning, and sprites. It can pull off a number of classic graphics tricks and demos. Oh yeah, and did we mention it runs on a freaking ATtiny85 and an I2C OLED screen?!

This is an amazing piece of work — if you’d asked us if this was possible, we would have probably said “no”. And now it’s yours to use in your own projects. The GitHub repo is full of demos showing off everything from switching between multiple layers, extremely rapid text scrolls, animations, boing balls, and even a Wolfenstein-style raycaster. On an ATtiny85.

There’s a demo video, embedded below, that shows it all off, but honestly you have to think about what’s going to to be suitably wowed. The first demo just seems to have a graphic wave over static text, for instance. No big deal? It’s blending the greyscale layers together and dithering them out to black and white for the OLED in real time! On an ATtiny85.

While the library is written in straight C++, there are even a couple examples of how you’d integrate this with Arduino’s Wire library if you so wished. We don’t know about you, but this makes us want to whip together an ATtiny85 and SSD1306 OLED demo board just to start playing around. This isn’t just an amazing hack, but it would also be a useful way to add graphics and a nice console to any project you’re working on.

Did we mention it’s all done on an ATtiny85?  Over I2C? Kudos!

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Flashing TI Chips With An ESP

April 3, 2022 by 29 Comments

Texas Instruments is best known to the general public for building obsolete calculators and selling them at extraordinary prices to students, but they also build some interesting (and reasonably-priced) microcontrollers as well. While not as ubiquitous as Atmel and the Arduino platform, they can still be found in plenty of consumer electronics and reprogrammed, and [Aaron] aka [atc1441] demonstrates how to modify them with an ESP32 as an intermediary.

Specifically, the TI chips in this build revolve around the 8051-core  microcontrollers, which [Aaron] has found in small e-paper price tags and other RF hardware. He’s using an ESP32 to reprogram the TI chips, and leveraging a web server on the ESP in order to be able to re-flash them over WiFi. Some of the e-paper displays have built-in header pins which makes connecting them to the ESP fairly easy, and once that’s out of the way [Aaron] also provides an entire software library for interacting with these microcontrollers through the browser interface.

Right now the project supports the CC2430, CC2510 and CC1110 variants, but [Aaron] plans to add support for more in the future. It’s a fairly comprehensive build, and much better than buying the proprietary TI programmer, so if you have some of these e-paper displays laying around the barrier to entry has been dramatically lowered. If you don’t have this specific type of display laying around, we’ve seen similar teardowns and repurposing of other e-paper devices in the past as well.

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Micropython On Microcontrollers

November 14, 2020 by 54 Comments

There are plenty of small microcontrollers available for all kinds of tasks, each one with its unique set of features and capabilities. However, not all of us want to spend time mucking about in C or assembly to learn the intricacies of each different chip. If you prefer the higher planes of Python instead, it’s not impossible to import Python on even the smallest of microcontrollers thanks to MicroPython, which [Rob] shows us in this project based on the ESP32.

[Rob] has been working on a small robot called Marty which uses an ESP32 as its brain, so the small microcontroller is already tasked with WiFi/Bluetooth communications and driving the motors in the robot. Part of the problem of getting Python to run on a platform like this is that MicroPython is designed to be essentially the only thing running on the device at any one point, but since the ESP32 is more powerful than the minimum requirements for MicroPython he wanted to see if he could run more than just Python code. He eventually settled on a “bottum-up” approach to build a library for the platform, rather than implementing MicroPython directly as a firmware image for the ESP32.

The blog post is an interesting take on running Python code on a small platform, and goes into some details with the shortcomings of MicroPython itself which [Rob] ended up working around for this project. He’s also released the source code for his work on his GitHub page. Of course, for a different approach to running Python and C on the same small processor, there are some libraries that accomplish that as well.