The BBC micro:bit single board ARM computer aimed at education does not feature as often as many of its competitors in these pages. It’s not the cheapest of boards, and interfacing to it in all but the most basic of ways calls for a slightly esoteric edge connector. We’re then very pleased to see that edge connector turned from a liability into a feature by [Fabien Chouteau] with his handheld console, he uses micro:bits preprogrammed with different games in the manner of game cartridges in commercial consoles.
The micro:bit sits in its edge connector on the underside of a handheld PCB above a pair of AAA batteries, while on the other side are an OLED display and the usual set of pushbuttons. It’s a particularly simple board as the micro:bit contains all the circuitry required to support its peripherals.
He’s coded the games using the Arduino IDE with a modified version of the Arduboy2 library that allows him to easily port Arduboy games written for Arduino hardware. It’s a work in progress as there are a few more features to incorporate, but the idea of using micro:bits as cartridges is rather special. There is a video of the console in action, which we’ve placed below the break.
I2S DAC PMOD – Used for stereo audio output of demodulated signals.
Combined with suitable firmware and FPGA design, these boards comprise a receiver capable of capturing 20kHz of signal from DC to over 1GHz, demodulating it with a variety of formats and driving high-quality audio.
RF input from the antenna can optionally be tuned down from VHF/UHF frequncies to an IF frequency in the HF range before passing to the ADC.
Raw HF or downconverted VHF at an IF of 5MHz is digitized to 14-bit resolution. The maximum input signal allowed without exceeing the range of the ADC puts the 0dBfs point of this system at -10dBm in 50 ohms. The ADC runs at 40MSPS with a resolution of 10 bits, providing approximately 60dB of dynamic range and 20MHz of bandwidth which places the quantization noise floor at about -70dBm.
From the ADC, data passes into the FPGA. This is an iCE5LP4k part which provides 20 4kb RAM blocks and 4 16×16 MAC blocks which are essential for the DSP required for the downconversion. In the FPGA the ADC data is pre-processed to a sample rate appropriate for the MCU. Figure 2 below shows the primary components of the FPGA design.
The C and Verilog source code is available on GitHub:
Hackaday World Create Day is on March 17th and it’s happening near you. Get together with hackers in your area and create something. Sign up now to host a World Create Day gathering! These are really easy to organize, but we can only do it with your help.
It used to be something of an electronic rite of passage, the construction of an FM bug. Many of us will have taken a single RF transistor and a tiny coil of stiff wire, and with the help of a few passive components made an oscillator somewhere in the FM broadcast band.
Ted Yapo had a small problem. As an amateur atronomer and astrophotographer, he needed a way to mark his expensive equipment so that he wouldn’t trip over it in the dark. Glow-in-the-dark materials were out because of they only glow for a short time, and glow sticks were also less than ideal because of their single-use nature. Tritium light sources would be perfect, barring the small details that they’re radioactive, expensive, and in the US only a few uses are allowed, most are prohibited by law.
So Yapo instead came up with an LED light that can run for not 20 hours, or even 20 days, but 20 yearson a single CR2032 coin cell battery!
For this week’s Hack Chat, we’re talking about trusting the autorouter. The autorouter is just a tool, and like any tool, it will do exactly what you tell it. The problem, therefore, is being smart enough to use the autorouter.
Our guest for this week’s Hack Chat is Ben Jordan, Director of Community Tools and Content at Altium. Ben is a Computer Systems engineer, with 25 years experience in board-level hardware and embedded systems design. He picked up a soldering iron at 8, and wrote some assembly at 12. He’s also an expert at using an autorouter successfully.
A few years ago, while managing the power management product line at work, I started an initiative with the development team to optimize new products by achieving ESE. ESE stands for Equations = Simulations = Experimentation. The idea is centered on the engineering goal of product design to verify that the systems design equations match the simulation results and ultimately the experimental results.
When these three items match, not only do you understand a system, but you have the best chance to optimize a better solution. I’ll have to say that in today’s mad dash to get new products out the door, achieving ESE is not always possible. But to break through the ordinary and have a chance for the extraordinary, I would say this is a requirement. Since this power supply is just a fun design for an upcoming nixie tube clock project of mine, I have the time to achieve ESE.
The updated schematic, BOM, Kicad Layout, and design files are located at Github:
An Unconference is the best way to put your finger on the pulse of what is happening in the hardware world right now. Everyone who attends should be ready to stand and deliver a seven-minute talk on something that excites them right now — this means you. The easiest thing to do is grab your latest hack off the shelf and talk about that.
Talks may be about a prototype, project, or product currently in progress at your home, work, or university. It could also be an idea, concept, or skill that you’re now exploring. The point is to channel your excitement and pass it on to others in a friendly presentation environment where everyone will cheer as your story unfolds.
Hackaday hosted an excellent Unconference in London back in September to a packed house for dozens of amazing presentations on a huge range of topics. We heard about bicycle turn signals, laser enhancing NES zappers, telepresence robots with IKEA origin stories, tiny-pitch LED matrix design, driving flip-dot displays, not trusting hardware 2-factor, and much more.
All the tickets for that event were scooped up in a few hours, and a huge waitlist followed. Don’t wait to grab your ticket!