Reading Resistors With OpenCV

May 14, 2015 by 42 Comments

Here’s a tip from a wizened engineer I’ve heard several times. If you’re poking around a circuit that has failed, look at the resistor color codes. Sometimes, if a resistor overheats, the color code bands will change color – orange to brown, blue to black, and so forth. If you know your preferred numbers for resistors, you might find a resistor with a value that isn’t made. This is where the circuit was overheating, and you’re probably very close to discovering the problem.

The problem with this technique is that you have to look at and decode all the resistors. If automation and computer vision is more your thing, [Parth] made an Android app that will automatically tell you the value of a resistor by pointing a camera at it.

The code uses OpenCV to scan a small line of pixels in the middle of the screen. Colors are extracted from this, and the value of the resistor is displayed on the screen. It’s perfect for scanning through a few hundred through hole resistors, if you don’t want to learn the politically correct mnemonic they’re teaching these days.

Video below, and the app is available for free on the Google Play store.

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Vacuum Gauge Display; Arduino Replaces Industrial

May 14, 2015 by 22 Comments

Arduinos! They’re a great tool that make the world of microcontrollers pretty easy, and in [cptlolalot]’s case, they also give us an alternative to buying expensive, proprietary parts. [cptlolalot] needed a gauge for an expensive vacuum pump, and rather than buying an expensive part, built a circuit around an Arduino to monitor the vacuum.

pressure-gauge-thumbThis project goes a little beyond simple Arduino programming though. A 12V to 5V power supply drives the device, which is laid out on a blank PCB. The display fits snugly over the circuit which reduces the footprint of the project, and the entire thing is housed in a custom-printed case with a custom-printed pushbutton. The device gets power and data over the RJ45 connection so no external power is needed. If you want to take a look at the code, it’s linked on [cptlolalot]’s reddit thread.

This project shows how much easier it can be to grab an Arduino off the shelf to solve a problem that would otherwise be very expensive. We’ve been seeing Arduinos in industrial applications at an increasing rate as well, which is promising not just because it’s cheap but because it’s a familiar platform that will make repairs and hacks in the future much easier for everyone.

Real-Virtual 3rd Person Skiing — Your Broken Bones Are The Video Game

May 14, 2015 by 11 Comments

Disappointed in the lack of proper VR games and the current technology, [Jonas Hjohlman] and some friends set out to make their own. They decided to go big or go home — and  built a device to let them ski in the third person.

We’ve seen this done as a proof of concept for walking around (and getting dizzy!) and even an attempt at third person driving which didn’t end well… We have to say, we’re pretty impressed at the Devil-may-care approach they take when trying to ski of all things — in the third person.

There’s not too much detail about the setup, but it looks like a standard pair of FPV goggles hooked up to their own wireless camera. A cameraman skier follows the player down the hill, and all the player sees is from behind.

Surprisingly, it goes a lot better than you think it would.

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Hackaday Prize Entry: A 7805 Replacement

May 13, 2015 by 75 Comments

The 7805 voltage regulator is a great device if you want a simple way of bringing a voltage down to 5V. It’s a three-pin, one-component solution that puts out five volts and a lot of heat. Simple, not efficient. For his Hackaday Prize entry, [K.C. Lee] is working on a much more efficient drop-in replacement for the 7805.

Linear regulators like the 7805 are great, but they’re not terribly efficient. Depending on the input voltage you might see 50% efficiency. Going to a switch mode supply, that efficiency shoot up to about 90%.

For his drop-in replacement, [K.C. Lee] is using the LM3485, a switch mode regulator that only needs a few extra parts to turn it into a replacement for the 7805. You will need a cap on the input, but you should already be putting those in your circuit anyway, right?

The 2015 Hackaday Prize is sponsored by:

wave generator

DIY Wave Energy Reclamation, Not So Complicated After All

May 13, 2015 by 27 Comments

We humans are becoming more aware every day that we need to reduce our fossil fuel dependence and move to more renewable methods lest we make the earth a less-desirable place to live. The sun is here today, and it will be tomorrow, harness that energy is one solution. There are places that are commonly windy, we can harness that energy too. [Jonathan] and [Ellen] set out to harness that wind energy but not in the traditional wind-turbine way. Wind creates ocean waves and the pair set out to recover some of that wave energy. They built a proof of concept and they did it on a budget with a side of DIY-style, to boot!

The device consists of a raft, with magnets attached to a sheet metal ruler standing on end. As you would expect, this ruler is flexible and the mass of the magnets easily sways back and forth as waves pass. The magnets move through stationary wire coils and as they do, creating an electrical current in the coils. The output of the coils is AC, which is then rectified to pulsed DC using several diodes and smoothed even further by some capacitors. The two DC outputs are then connected in series to double the voltage to 5 with a max current of about 20mA.

For this experiment the generator powers a modified smoke alarm which keeps burglars away from a coral reef. But the team could see this powering lights on buoys or low-power sensors. What would you use it for?

An Amazon Dash-Like Button For The ESP8266

May 13, 2015 by 13 Comments

The Amazon Dash Button is a tiny piece of hardware that contains a single pushbutton, a WiFi module, and a nice, shiny corporate logo. Press the button, and products with that logo will be delivered to your house. An impressive bit of marketing, at least. With small, cheap WiFi modules like the ESP8266, it was only a matter of time until something an Amazon Dash clone was developed.

[deqing] created an ESP8266 Dash Button using the ESP-12 module, a button, a 3D printed case, and a pair of AA batteries. Electronically, it’s extremely simple; press the button, the ESP will wake up, request a URL, and put itself back to sleep. That’s all you need to do when you’re replicating the functionality of the Amazon Dash Button – the server will take care of the rest.

To configure the ESP8266, [dequng] is using the ESP-TOUCH app for Android, and setting up new functionality in this ESP button is as simple as putting a URL in the button’s Flash.

Not only is this a great build that has literally hundreds of different uses, it’s also not a breakout board for the ESP8266. It’s great that we’re finally seeing some builds using this cheap WiFi chip in the real world.

Obviously the actual Dash buttons include authentication that this one does not. We recently saw a teardown of the original hardware. We’re still waiting for in-depth analysis of the data squirted to the internet when an order is placed with it, though.

Arduino IDE Becomes More Open, Less Snarky

May 13, 2015 by 56 Comments

Version 1.6.4 of the Arduino IDE has been out for a little while now, and it has a couple of notable changes. To our eyes, the most interesting change makes adding support for non-standard boards and their configurations within the Arduino IDE a lot simpler. We’ll get into details below.

unnamedBut before that, it’s time to bid farewell to the cheeky little popup window that would deliver a warning message when using a board bearing the USB IDs of their former-partner-turned-competitor. We absolutely agree with [Massimo] that the issues between Arduino SRL / Smart Projects and Arduino LLC are well-enough known in the community, and that it’s time for the popup to fade away.

Now on to the meat of this post. The new “Board Manager” functionality makes it significantly easier for other non-Arduino products to be programmed within the Arduino IDE. Adafruit has a tutorial on using the Board Manager functionality with their products, and it basically boils down to “enter the right URL, click on the boards you want, download, restart Arduino, bam!”

The list of unofficially supported third-party boards is still a bit short, but it includes some stellar entries. For instance, Adafruit has provided the files needed for the ESP8266, which recently received the Arduino treatment. This means that you can simply point your IDE at Adafruit’s URL, and it’ll set you up with everything needed to develop for the ESP8266 from within the comfy Arduino IDE.

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