OpenAstroTracker is a tracking and GoTo mount for DSLR astrophotography

Stars appear to stand still, but wait a few minutes and they won’t be in quite the same place. This means that if you want to take a long-exposure image of the sky with your DSLR you’ll have to either embrace the streaks, or use tracking hardware to compensate for this movement. Naturally, this specialized equipment can be quite expensive, but a seen here, you can now make your own 3D-printed OpenAstroTracker controlled by an Arduino Uno.

The device features a 16×2 LED display/keypad shield, along with an optional Bluetooth module for interface. When set up, it slowly rotates the camera to compensate for star movements via two steppers on a gimbal assembly. 

Print files for the OpenAstroTracker are available on Thingiverse and code can be found on GitHub if you’d like to examine the design or even build your own. Its creator also plans to sell it as a DIY kit — and you can sign up to be notified when it’s available.

Arduino Blog 26 Feb 14:06

Gravity-Defying Water Droplet Fountain Gets An Upgrade

When we last saw [isaac879]’s levitating RGB time fountain, it was made of wood which meant that it would absorb water and didn’t really show off the effect very well. His new version solves this problem with an acrylic case, new PCB and an updated circuit.

Like the original, this project drops water past strobing RGB LEDs creating an illusion of levitating, undulating colored water droplets. The pump at the top creates the droplets, but the timing has a tendency to drift over time. He thus implemented a PID controller to manage the pump’s drip rate, which was done by having the droplets pass by an infrared diode connected to an ATTiny85. The ’85 used the diode and PWM to control the pump motor speed and communicated to the Arduino over I2C.

The video shown below shows the whole process of designing and building the new time fountain. Everything from circuit and PCB design to 3D printing to assembly is shown along with narration describing what’s going on in case you want to build one yourself. If you do, all the files and components required are listed in the info section of the video.

There’s more that [isaac879] wants to do to improve the time fountain, but V2 looks great. It’s sleeker and smaller than the original and solves some of the design issues of the first. For more inspiration, check out some of the other levitating water fountain projects that have been posted over the years.

Self-Playing Kalimba V2 Thanks to Readers Like You

Would you like to know the great thing about this community we have here? All the spitballing that goes on every day in the comments, the IO chat rooms, and in the discussion threads of thousands of projects. One of our favorite things about the Hackaday universe is that we help each other out, and because of that, our collective curiosity pushes so many designs forward.

[Gurpreet] knows what we’re talking about. He’s back with version two of his self-playing kalimba, driven as strongly as ever by the dulcet tones of the Avatar theme. Now the robo-kalimba is rocking two full octaves, and thanks to your comments and suggestions, has relocated the servos where they can’t be picked up by the soundboard.

We gasped when we saw the new mechanism — a total of 15 rack and pinion linear actuators that make the kalimba look like a tiny mechanical pipe organ. Now the servos float, fixed into a three-part frame that straddles the sound box. [Gurpreet] melted servo horns to down to their hubs rather than trying to print something that fits the servos’ sockets.

Thumb your way past the break to check out the build video. [Gurpreet] doesn’t shy away from showing what went wrong and how he fixed it, or from sharing the 3D printering sanity checks along the way that kept him going.

Plucking kalimba tines is a difficult problem to solve because they’re stiff, but with timbre sensitive to many degrees of pressure. A slightly easier alternative? Make a toy player piano.

Levitating Starship Model Comes In For a Landing

If everything goes according to plan, Elon Musk says the first generation of SpaceX’s massive Starship will make an orbital flight before the end of 2020. That’s a pretty bold claim, but when you’ve made landing rockets on their tails as in the old science fiction pulp magazines seem routine, we suppose you’ve earned the right to a bit of bravado. We’re excited to see the vehicle evolve over the next several months, but even if the real one stays grounded, we’ll gladly take this “flying” Starship model from [Chris Chimienti] as a consolation prize.

A magnetic levitation module, we’re officially in the future.

Feeling a bit let down by the 3D printable models of the Starship he found online, [Chris] set out to build his own. But it wasn’t enough to just make his bigger, stronger, and more accurate to Starship’s current design; he also wanted to make it a bit more exciting. Some RGB LEDs an Arduino embedded in the “cloud” stand the rocket sits on was a good start, and the landing pad inspired by SpaceX’s real autonomous spaceport drone ship Just Read the Instructions looks great all lit up.

But this is Starship we’re talking about, a vehicle that could literally push humanity towards being a multi-planet species. To do it justice, you’ve really got to knock it out of the park. So [Chris] found a magnetic levitation module online that could support a few hundred grams, and set to work on making his plastic Starship actually hover over the landing pad.

As you might imagine, it was a bit tricky. The first versions of the rocket looked great but came out too heavy, so he switched over to printing the model in so-called “spiral vase mode” which made it entirely hollow. Now far lighter and with a magnetic plate fit into the bottom, it was stable enough to float on its own. For the final touch, [Chris] added some red LEDs and a coin cell battery to the base of the Starship so it looks like the sleek craft is performing a last-second landing burn with its “impossible” full-flow staged combustion engines.

This isn’t the first time we’ve seen a model rocket with an electronic glowing cloud under it, but it’s certainly the first one we’ve seen that could levitate in mid-air. While this little rocket might not make it all the way to Mars, we wouldn’t be surprised to see it touching down on the desks of other hackers and makers in the near future.

LoRa Tutorials For The DIY Masses

LoRa is the go-to tech for low power, long range wireless sensor networks. Designing with off-the-shelf modules can be a boon or a bane depending on the documentation and support. Luckily, [Renzo] has prepared a set of tutorials to get you started.
In his seven part series of write-ups, [Renzo] starts by connecting the E32 module from AliExpress to an Arduino as well as an ESP8266 to demonstrate essential communications. Then he discusses the configuration options and the library he created to make like a bit easier. Following that is a series of posts discussing transmission types as well as power saving methods including sleep modes and wake-on-radio.
The information will be extremely handy for someone starting off with the SX1276/SX1278 Wireless Modules which are relatively inexpensive as opposed to more standardized development kits. We love the abundance of fritzing diagrams, arduino code and helper library and hope someone will build on it. You can get the library from Github for your tinkering pleasure.
If you are looking for ideas for this newly discovered skill, have a look at LoRa Enabled Mailbox as well as Electric Fence Monitoring with The Things Network for a bit of IoT action.

Resys is an LED drawer system that makes it easy to find your resistors

You’ve got your design ready to go, you know you have the right components… but where exactly did you place that particular resistor? With the Resys drawer system by Lynlimer, you no longer have to wonder — just type in the needed value and the proper drawer lights up automatically.

The device is based on an Arduino Nano, with an LCD display for text output and a numeric keypad for value entry. The proper drawers are lit via WS2812B addressable LEDs, held in 3D-printed holders. 

It’s a clever project that could be expanded to well beyond the 16 drawers now used. Code, STLs, and circuit diagrams are available in Lynlimer’s write-up if you want to make your own!

Arduino Blog 25 Feb 16:25
arduino  featured  nano  

Take control of your dashboard — the new Arduino IoT Cloud Dashboard with advanced features!

The new dashboard for the Arduino IoT Cloud comes with a host of enhanced features. It allows you to gather and display data from multiple IoT devices in one dashboard, and control those devices as required through your dashboard to fully integrate your solution.

Using widgets to connect to the properties enables you to set up a new dashboard in minutes, and you can fully customize your dashboard by: grouping devices however you like, dragging and dropping to rearrange the layout, and selecting from multiple options to visualize the data.

It is now possible to import historical data into the dashboard to provide a backdated view for all your properties, hence creating a new dashboard  no longer means losing previous information. You can present the information in your dashboard as far back as you’ve been collecting the data.

A new ‘duplicate dashboard” function lets you copy any of your existing dashboards setup and layout, plus you can easily see which things are associated with which devices when setting up a new solution.

It really is that simple!

ARDUINO TO AVR

Forums

Hi is anyone able to help me convert this arduino code to avr. Trying to make a sound pressure level meter using the same idea as this link https://circuitdigest.com/microcontroller-projects/arduino-sound-level-measurement just need to change the code to avr. I am using the atmega 164p.

const int MIC = 0; //the microphone amplifier output is connected to pin A0
int adc;
int dB, PdB; //the variable that will hold the value read from the microphone each time

Circuit Digest 23 Feb 19:14

Warnings in P10 Led DIsplay Board Program

Sir I am finding the following errors while executing the P10 led matrix code

Circuit Digest 23 Feb 14:56

Espresso Machine Now Powers Plants

This thing has what plants crave! No, not electrolytes exactly — just water, light, and moisture polling every 30 minutes. We think it’s fitting to take something that once manufactured liquid liveliness for humans and turn it into a smart garden that does the same thing for plants.

So let’s just get this out of the way: the espresso machine was abandoned because it was leaking water from a gasket. [The Plant Bot] cleaned it up, replaced the gasket, and got it brewing, and then it started leaking hot water again from the same gasket. We might have gone Office Space on this beautiful machine at that point, but not [The Plant Bot].

Down in the dirt, there’s a soil moisture sensor that’s polling every 30 minutes. If the moisture level falls below the threshold set appropriately at a life-sustaining 42%, the Arduino is triggered to water the plant through a relay board using the espresso machine’s original pump. If the plant is dry, the machine will pump water for two seconds every minute until the threshold is met. [The Plant Bot] tied it all together with a nice web interface that shows plant data and allows for changes over Bluetooth.

[The Plant Bot] started by disconnecting the heating element, because plants don’t tend to like hot steam. But if the cup warming tray along the top has a separate heating element, it might be neat to reuse it for something like growing mushrooms, or maintaining a sourdough starter if the temperature is right.

Via r/duino