Early on in the year, Hackaday published one of its short daily pieces about plans from the people behind altpwr.net for a low voltage DC power grid slated for the summer’s SHACamp 2017 hacker camp in the Netherlands. At the time when it was being written in the chill of a Northern Hemisphere January the event seemed so far away, but as the summer fades away along with the deep tan many SHACamp attendees gained in the Dutch sunlight it’s worth going back and revisiting the project. Did they manage it, and how did they do? This isn’t really part of our coverage of SHACamp itself, merely an incidental story that happens to have the hacker camp as its theatre. Continue reading “That Decentralised Low Voltage Local DC Power Grid, How Did It Do?”
Have a beautiful antique radio that’s beyond repair? This ESP8266 based Internet radio by [Edzelf] would be an excellent starting point to get it running again, as an alternative to a Raspberry-Pi based design. The basic premise is straightforward: an ESP8266 handles the connection to an Internet radio station of your choice, and a VS1053 codec module decodes the stream to produce an audio signal (which will require some form of amplification afterwards).
Besides the excellent documentation (PDF warning), where this firmware really shines is the sheer number of features that have been added. It includes a web interface that allows you to select an arbitrary station as well as cycle through presets, adjust volume, bass, and treble.
If you prefer physical controls, it supports buttons and dials. If you’re in the mood for something more Internet of Things, it can be controlled by the MQTT protocol as well. It even supports a color TFT screen by default, although this reduces the number of pins that can be used for button input.
The firmware also supports playing arbitrary .mp3 files hosted on a server. Given the low parts count and the wealth of options for controlling the device, we could see this device making its way into doorbells, practical jokes, and small museum exhibits.
To see it in action, check out the video below:
Sometimes the most important thing is getting something done.
[Alex Lao] was recently in such a situation. His sister was getting married and he designed, built, and delivered twenty RGB LED table centerpieces in a rush. There were no prototypes made, and when the parts arrived all twenty were built all at once over a single weekend. These table centerpieces are illuminated by RGB LEDs and battery-powered, but have an option to be powered by a wall adapter.
[Alex] helpfully shared some tips on reducing the production risks and helping ensure results in such a limited time frame. His advice boils down to this: reduce the unknowns. For Alex this meant re-using code and components from a previous project — even if they were not optimal — so that known-good schematic and footprint libraries could be used for the design.
From one perspective, the PIC32 microcontroller inside each lamp is overkill for an LED centerpiece. From another perspective, it was in fact the perfect part to use because it was the fastest way for [Alex] to get the devices working with no surprises.
For an added perspective on needing to get production right the first time on a much larger scale, be sure to check out getting an installation made up of 25,000 PCBs right the first time.
At first glance, the ColibriNANO SDR looks like another cheap SDR dongle. But after watching [Mile Kokotov’s] review (see video below), you can see that it was built specifically for software defined radio service. When [Mile] takes the case off, you notice the heavy metal body which you don’t see on the typical cheap dongle. Of course, a low-end RTL-SDR is around $20. The ColibriNANO costs about $300–so you’d hope you get what you pay for.
The frequency range is nominally 10 kHz to 55 MHz, although if you use external filters and preamps you can get to 500 MHz. In addition to a 14-bit 122.88 megasample per second A/D converter, the device sports an Altera MAX10 FPGA.
Digital color theory can be a tricky concept to wrap one’s mind around – particularly if you don’t have experience with digital art. The RGB color model is about as straightforward as digital color mixing gets: you simply set the intensity of red, green, and blue individually. The result is the mixing of the three colors, based on their individual intensity and the combined wavelength of all three. However, this still isn’t nearly as intuitive as mixing paint together like you did in elementary school.
To make RGB color theory more tangible, [Tore Knudsen and Justin Daneman] set out to build a system for mixing digital colors in a way that reflects physical paint mixing. Their creation uses three water-filled containers (one each for red, green, and blue) to adjust the color on the screen. The intensity of each color is increased by pouring more water into the corresponding container, and decreased by removing water with a syringe.
An Arduino is used to detect the water levels, and controls what the user sees on the screen. In one mode, the user can experiment with how the color levels affect the way a picture looks. The game mode is even more interesting, with the goal being to mix colors to match a randomly chosen color that is displayed on the screen.
The practical applications for this project may be somewhat limited, but as an interactive art piece it’s hypnotizing. And, it may just help you with understanding RGB colors for your next project.
Here’s a rec-room ready hack: an automatic drink dispenser.
[truebassB]’s dispenser operates around a 555 timer, adjusted by a potentiometer. Push a button and a cup pours in a few seconds, or hold the other button to dispense as much as you want.
The dispenser is made from MDF and particle board glued together, with some LEDs and paper prints to spruce it up. Just don’t forget a small spill sink for any miscalculated pours. You needn’t fret over the internals either, as the parts are easily acquired: a pair of momentary switches, a 12V micro air pump, a brass nozzle, food-safe pvc tube, a custom 555 timing circuit — otherwise readily available online — a toggle switch, a power supply plug plus adapter and a 12V battery.
Hi-Fi hasn’t changed much in decades. OK, we’ll concede that’s something of a controversial statement to make in that of course your home hi-fi has changed immensely over the years. Where once you might have had a turntable and a cassette deck you probably now have a streaming media player, and a surround sound processor, for example.
But it’s still safe to say that hi-fi reproduction hasn’t changed much in decades. You can still hook up the latest audio source to an amplifier and speakers made decades ago, and you’ll still enjoy great sound.
Not so though, if instead of a traditional amplifier you bought an AV receiver with built-in amplifier and processing. This is a fast-moving corner of the consumer electronics world, and the lifetime of a device before its interfaces and functionality becomes obsolete can often be measured in only a few years.
To [Andrew Bolin], this makes little sense. His solution has some merit, he’s produced a modular open-source AV processor in which the emphasis is on upgradeability to keep up with future developments rather than on presenting a black box to the user which will one day be rendered useless by the passage of time.
His design revolves around a backplane which accepts daughter cards for individual functions, and a Raspberry Pi to do the computational heavy lifting. So far he has made a proof-of-concept which takes in HDMI audio and outputs S/PDIF audio to his DAC, but plans are in hand for further modules. We can see that this could become the hub of a very useful open-source home entertainment system.
If you make one, please remember to enhance it with our own sound-improving accessory.