Dual Axis Solar Tracker With Online Energy Monitor

July 24, 2016 by Gerrit Coetzee 57 Comments

[Bruce Helsen] built this dual axis solar tracker as one of his final projects for school.

As can be experimentally verified in a very short timeframe, the sun moves across the sky. This is a particularly troublesome behavior for solar panels, which work best when the sun shines directly on them. Engineers soon realized that abstracting the sun away only works in physics class, and moved to the second best idea of tracking sun by moving the panel. Surprisingly, for larger installations the cost of adding tracking (and its maintenance) isn’t worth the gains, but for smaller, and especially urban, installations like [Bruce]’s it can still help.

[Bruce]’s build can be entirely sourced from eBay. The light direction is sensed via a very clever homemade directional light sensor. A 3D printer extruded cross profile sits inside an industrial lamp housing. The assembly divides the sky into four quadrants with a light-dependent resistor for each. By measuring the differences, the panel can point in the optimal direction.

The panel’s two axis are controlled with two cheap linear actuators. The brains are an Arduino glued to a large amount of solar support electronics and the online energy monitor component is covered by an ESP8266.

The construction works quite well. If you’d like to build one yourself the entire BOM, drawings, and code are provided on the instructables page.

MicroPython On The ESP8266: Kicking The Tires

July 21, 2016 by Elliot Williams 32 Comments

Scripting languages are for large computers, right? “Real” embedded device work is a hellish, never-ending cycle of code, compile, and re-flash. Well, I used to think so too, but with the proliferation of scripting and other interactive languages to microcontrollers over the last few years, the hurdle to interactive development on the small chips has gotten a lot lower.

On the ESP8266 platform, I’ve tried out NodeMCU’s Lua and ESP8266 BASIC. (For the last half-year, I’ve been using the awesome Mecrisp-Stellaris almost exclusively on the STM32F1xx and F4xx chips, but haven’t dipped into ESP8266 Forth yet.)

NodeMCU is great because it’s got everything you could want built in, and through cloud services it’s easy to get a tailored build made that maximizes free flash memory for your projects. I just don’t dig the asynchronous Lua thing (you might, try it!). ESP BASIC has a different set of libraries, and is missing MQTT for my purposes. Still it’s pretty slick, and worth a look.

So when the MicroPython folks announced that they were releasing the binary builds for the ESP, I thought it was time to give it a spin. I’ve used Python for nearly twelve years now, so it’s like a comfortable shoe for me. Would MicroPython be the same on the ESP8266? The short answer is yes and no.

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Never Gonna Give Up Free WiFi

July 19, 2016 by Elliot Williams 44 Comments

Our conscience almost prevented us from posting this one. Almost.

What do people all around the world want most? Free WiFi. And what inevitable force do they want to avoid most, just after death and taxes? Rick Astley. As a getting-started project with the ESP8266, Hackaday.io user [jaime] built a “free WiFi portal” that takes advantage of people’s deepest desires. Instead of delivering sweet, high-bandwidth connectivity, once you click through the onerous terms and conditions, it delivers you a looped GIF with background music.

And all of this on $4 worth of hardware, with firmware assembled in the cloud and easily available to anyone. We live in a truly ~~frivolous~~ glorious age.

Digging through our archives, we found a number of Rickroll posts that we’d rather forget, but this steam-powered record player bears a second look.

Hackaday Links: July 17, 2016

July 17, 2016 by Brian Benchoff 23 Comments

There’s going to be a new Nintendo console for Christmas! It’s the NES Classic Edition. It looks like a minified NES, with weird connectors that look like the connector for the Wii Nunchuck. There are no other details.

A site called “Motherboard” reports assembling a computer is too hard and a ‘nerve-wrecking [sic]’ process. Tip of the stovepipe to the Totalbiscuit.

When I was in elementary school, the playground had a twenty foot tall metal slide that faced South. During my time there, at least three of my classmates fell off it, and I distinctly remember the school nurse’s aid running past me on the playground with a wheelchair. There wasn’t soft mulch or the weird rubber granules under this slide – just hard, compacted dirt. This slide was awesome, even if it was torn down when I was in third grade. [Brandon Hart]’s kid’s won’t look back fondly on their youth with experiences like these; he built a water-cooled slide in his backyard. He’s getting an 80°F ΔT with a trip to Ace Hardware, probably $20 in fittings, and a drill. Neat.

This is probably better suited for an ‘Ask Hackaday’ column, but [Arsenijs] has run into a bit of a problem with his Raspberry Pi Project. He’s trying to use a planarized kernel module to obfuscate the SPI bus, but he can’t do that because of a oblivated drumble pin. He could, of course, deenumerate several of the GISP modules, but this would cause a buffer underflow and eventually wreck the entire cloudstack. I told him he should use Corrosion, but he seems dead set on his Hokey implementation. If anyone has any ideas, get the glamphs and put it on the grumbo.

The Owon SDS7102 oscilloscope is a small, cheap, two-channel scope that is impressive for its price but noisier than you would expect. This scope has been thoroughly reverse engineered, and now Linux is running on this scope. This Linux scope has a working VGA display, USB host, USB device, Flash, and working Ethernet. The entire analog front end has been reversed engineered, and somehow this is now the most open oscilloscope you can buy.

The ESP32 is Espressif’s followup to their very popular ESP8266 WiFi module. The ESP32 will be much more powerful and include Bluetooth when it’s released in August. Until then, [Pighixxx] has the complete pinout for the ESP32.

Planespotter Spots Planes, Tracks Destinations

July 17, 2016 by Richard Baguley 11 Comments

Ever looked up in the sky and wondered where all of those planes above you were going? [squix] no longer has to, thanks to his ESP8266-based Planespotter.

He built this nifty device to grab the details of the flights he sees taking off from Zurich airport. It’s a neat build, running on an ESP8266 that receives ADS-B data from ADS-B Exchange. This service allows you to query the ADS-B data with a specific location.

[squix]’s plane tracker sends a query to ADS-B exchange for flights in his location and below a certain height (so he sees ones that are just taking off), then displays the received information on the OLED screen. He says a display-only version will run you around $20, while the full version that also receives and shares data with the ADS-B Exchange will cost you about $50. That’s a lot cheaper than a plane ticket…

Your ESP8266 Needs More Memory

July 16, 2016 by Elliot Williams 44 Comments

We just got through reviewing MicroPython on the ESP8266, and one of the main takehomes is that our ESP modules need more flash memory. You may be in the same boat — the earliest (and cheapest) modules on the market only had 512 kB of flash. For over-the-air programming, or to give you some more space for fancier programs, you’re going to want 1 MB or even 4 MB.

The solution? Just buy a new flash chip and solder it on. This is especially easy if you’ve got an ESP-01, ESP-03, or ESP-11 modules where the flash chip is exposed. Desolder, resolder, done. It can be a little trickier for those modules with a tin can around chips, but that’s nothing that a little hot air can’t fix. See the video embedded below for a good walk-through.

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Baby Monitor Rebuild Is Also ESP8266 Audio Streaming How-To

July 15, 2016 by Donald Papp 18 Comments

[Sven337]’s rebuild of a cheap and terrible baby monitor isn’t super visual, but it has so much more going on than it first seems. It’s also a how-to for streaming audio via UDP over WiFi with a pair of ESP8266 units, and includes a frank sharing of things that went wrong in the process and how they were addressed. [Sven337] even experimented with a couple of different methods for real-time compression of the transmitted audio data, for no other reason than the sake of doing things as well as they can reasonably be done without adding parts or spending extra money.

The original baby monitor had audio and video but was utterly useless for a number of reasons (French). The range and quality were terrible, and the audio was full of static and interference that was just as loud as anything the microphone actually picked up from the room. The user is left with two choices: either have white noise constantly coming through the receiver, or be unable to hear your child because you turned the volume down to get rid of the constant static. Our favorite part is the VOX “feature”: if the baby is quiet, it turns off the receiver’s screen; it has no effect whatsoever on the audio! As icing on the cake, the analog 2.4GHz transmitter interferes with the household WiFi when it transmits – which is all the time, because it’s always-on.