There’s a certain kind of joy that comes in throwing something together from spare parts, or from finding utility in a proof of concept for another project. [Clewsy] is cooking up something clacky and built this baby keeb to prove some stuff out, such as reading a key matrix. Now it’s become a music/media controller that looks great next to a giant matching volume knob.
Beneath the gently backlit Gateron blues is a custom ATMega32u4-based board, which is viewable through the clear acrylic bottom plate. That’s a nice touch. We’re not sure if the wood came from a picture frame, but if not, they seem like a great candidates for enclosure material.
This keeb looks fantastic, and we are partial to both the clear and the chrome keycaps. We can only hope [Clewsy] sends the details of the next build our way.
If you want to get started building keyboards, you can’t go wrong with a macro keyboard like this one. If you have way more than four macros in mind, build something bigger, like a custom game pad with a joystick.
[Martin Fasani] has set out to build a beautiful low power E-Ink Calendar he can hang on his wall. But perhaps more importantly, the work he has done makes it easier for everyone in the future to have a e-ink display. Many battery-powered e-ink projects connect to some server, download a bitmap image, display the new image, and then go into a deep sleep power mode. [Martin’s] project is no different, but it uses a handy microservice that does the conversion and rendering for you.
The firmware for this ESP32/ESP32S2 based calendar is open sourced on GitHub, with a version based on the Arduino framework as well as the native ESP-IDF framework. One particularly fantastic part of the firmware is a C++ component called CalEPD that drives e-paper displays. CalEPD extends the Adafruit_GFX class and is broken out in a separate repo, making it easy to consume on other projects. Since this supports dozens of different e-paper displays, this simplifies the process of building a calendar with different screens. The firmware includes a Bluetooth setup flow from a smartphone or tablet. This means you can quickly configure how often it wakes up, what it queries, and other important features.
The hardware shown in the demo video has a 7.5″ Waveshare screen with 800 x 400 resolution nestled inside a 3D-printed shell. There is also a 5,000 mAh battery with an ESP32 TinyPICO powering the whole system. The TinyPICO was picked for its incredible deep sleep power consumption. All this fits into a frame just 11 mm thick, for which STL files are available. [Martin] continues to work on this calendar display and has recently added support for FocalTech touch panel controllers. We’re excited to see where he takes it next!
This isn’t the first e-ink display project we’ve seen but this is a great reference to build your own. If you need another good starting point, this weather display might give you that little bit of inspiration you need.
Dishwashers are great at washing dishes and even rinsing them, most of the time. Where they tend to fail is in the drying part. Somehow these things dry hot enough to warp stoneware dishes, but not so well that things are actually dry when you open the door. Blame it on the lack of air movement.
[Ivan Stepaniuk] is listening for the dishwasher’s frequencies with a microphone, amplifying them with a trusty LM386, and using an STM32 blue pill to crunch the audio. [Ivan] has plans to incorporate an ESP8266 board for IoT, presumably to get a notification when the door has been opened successfully. Check out the demo after the break.
Some may ask why you’d want to program a Cortex-M microcontroller like the STM32 series using nothing but the ARM toolchain and the ST Microelectronics-provided datasheet and reference manual. If your first response to that question wasn’t a panicked dive towards the nearest emergency exit, then it might be that that question has piqued your interest. Why, indeed?
Definitely, one could use any of the existing frameworks to program an STM32 MCU, whether the ST HAL framework, plain CMSIS, or even something more Arduino-flavored. Yet where is the fun in that, when at the end of the day one is still fully dependent on that framework’s documentation and its developers? More succinctly, if the contents of the STM32 reference manuals still look like so much gibberish, does one really understand the platform?
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.
As a debugger, GDB is a veritable Swiss Army knife. And just like exploring all of the non-obvious uses of a those knives, your initial response to the scope of GDB’s feature set is likely to be one of bewilderment, subsequent confusion, and occasional laughter. This is an understandable reaction in the case of the Swiss Army knife as one is unlikely to be in the midst of an army campaign or trapped in the wilderness. Similarly, it takes a tricky debugging session to really learn to appreciate GDB’s feature set.
If you have already used GDB to debug some code, it was likely wrapped in the comfort blanket of an IDE. This is of course one way to use GDB, but limits the available features to what the IDE exposes. Fortunately, the command line interface (CLI) of GDB has no such limitations. Learning the CLI GDB commands also has the advantage that one can perform that critical remote debug session even in the field via an SSH session over the 9600 baud satellite modem inside your Swiss Army knife, Cyber Edition.
Have I carried this analogy too far? Probably. But learning the full potential of GDB is well worth your time so today, let’s dive in to sharpen our digital toolsets.
While the cost of a hobby-grade remote control transmitter has dropped significantly over the last decade or so, even the basic models are still relatively expensive. It’s not such a big deal if you only need to get one for personal use, but for a school to outfit a classroom’s worth of students their own radios, they’d need to have a serious STEM budget.
Which is why [Miharix], himself an educator with a decade of experience, developed a project that leverages the ESP8266 to create affordable RC vehicles that can be controlled with a smartphone’s web browser. There’s a bit of irony at play since the smartphones are more expensive than the RC transmitters would have been; but with more and more school-age kids having their own mobile devices, it takes the cost burden off of the educators. Depending on the age of the students, the teacher would only need to keep a couple of burner phones on hand for student that doesn’t have a device of their own.
A custom PCB makes connections easier for students.
In its fully realized form, the project uses an open hardware board that allows standard RC hobby servos to be connected to the GPIO pins of a ESP-12E module. But if you don’t want to go through the trouble of building the custom hardware, you could put something similar together with an ESP development board. From there it’s just a matter of installing the firmware, which starts up a server providing a touch-based controller interface that’s perfect for a smartphone’s screen.
Since the ESP8266 pops up as an Access Point that client devices can connect to, you don’t even need to have an existing network in place. Or Internet access, for that matter. [Miharix] says that in tests, the range between a common smartphone and the ESP8266 is approximately 85 meters (260 feet), which should be more than enough to get the job done.
Beneath the gently backlit Gateron blues is a custom ATMega32u4-based board, which is viewable through the clear acrylic bottom plate. That’s a nice touch. We’re not sure if the wood came from a picture frame, but if not, they seem like a great candidates for enclosure material.
