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Under the Hood – What Does this Board Do?

พฤ, 03/19/2015 - 18:01

As interesting as it is to look at the insides of de-capped chips, it is equally interesting to sometimes look at old circuit boards and try to figure out the various sections, their functions, and to look at some of the design practices used. At a local electronics flea market, [daqq] recently chanced upon quite a large PCB that seemed to have come from some HP system, and picked it up for about 6 – the value of the abundant oscillators, crystals, connectors and other miscellaneous components that could be recovered seemed much more than what he paid for the board.

The board in question turned out to be from a HP 9000 Superdome system – part of the PA-8xxx based server series which packs quite a punch. This particular one was the 500MHz system UGUY5-500 board. At this point, most of [daqq]’s analysis is based on what he can visually decipher looking at the chip numbers and associated parts. He’s taken a stab at guessing the function of the board itself, and of the various parts on it. He’s put up high resolution scanned images of the board, for any of our readers who would like to offer an insight in to this board or the system that it was part of. Apparently, he has quite a few more exotic server PCB’s lined up for sleuthing, if you folks enjoy this.


Filed under: teardown

DIY Oscilloscope with a Scanning Laser

พฤ, 03/19/2015 - 15:00

If you’ve ever used an old-school analog oscilloscope (an experience everyone should have!) you probably noticed that the trace is simply drawn by a beam that scans across the CRT at a constant rate, creating a straight line when there’s no signal. The input signal simply affects the y-component of the beam, deflecting it into the shape of your waveform. [Steve] wrote in to let us know about his home-built “oscilloscope” that works a lot like a simple analog oscilloscope, albeit with a laser instead of  a CRT.

[Steve]’s scope is built out of a hodgepodge of parts including Lego, an Erector set, LittleBits, and a Kano Computer (based on a Raspberry Pi). The Pi generates a PWM signal that controls the speed of a LittleBits motor. The motor is hooked up to a spinning mirror that sweeps the laser across some graph paper, creating a straight laser line.

After he got his sweep working, [Steve] took a small speaker and mounted a mirror to its cone. Next he mounted the speaker so the laser’s beam hits the mirror on the speaker, the spinning sweep mirror, and finally the graph paper display. The scope’s input signal (in this case, audio from a phone) is fed into the speaker which deflects the laser beam up and down as it is swept across the paper, forming a nice oscilloscope-like trace.

While [Steve]’s scope might not be incredibly usable in most cases, it’s still a great proof of concept and a good way to learn how old oscilloscopes work. Check out the video after the break to see the laser scope in action.


Filed under: hardware, tool hacks

New Part Day: SPI RAM and a Video Controller

พฤ, 03/19/2015 - 12:00

Generating video signals with a microcontroller or old CPU is hard if you haven’t noticed. If you’re driving even a simple NTSC or PAL display at one bit per pixel, you’re looking at a minimum of around 64kB of RAM being used as a frame buffer. Most microcontrollers don’t have this much RAM on the chip, and the AVR video builds we’ve seen either have terrible color or relatively low resolution.

Here’s something interesting that solves the memory problem and also generates analog video signals. Yes, such a chip exists, and apparently this has been in the works for a very long time. It’s the VLSI VS23s010C-L, and it has 131,072 bytes of SRAM and a video display controller that supports NTSC and PAL output.

There are two chips in the family, one being an LQFP48 package, the other a tiny SMD 8-pin package. From what I can tell from the datasheets, the 8-pin version is only an SPI-based SRAM chip. The larger LQFP package is where the action is, with parallel and SPI interfaces to the memory, an input for the colorburst crystal, and composite video and sync out.

After looking at the datasheet (PDF), it looks like generating video with this chip is simply a matter of connecting an RCA jack, throwing a few commands to the chip over SPI, and pushing bits into the SRAM. That’s it. You’re not getting hardware acceleration, you’re going to have to draw everything pixel by pixel, but this looks like the easiest way to generate relatively high-resolution video with a single part.

Thanks [antibyte] for the tip on this one.


Filed under: parts

Sharpening Knives Using a Bread Slicer?

พฤ, 03/19/2015 - 09:00

[Joekutz] wrote in to tell us about his very interesting creation — a knife whetting machine, built from an automated bread slicer. Confused? So were we when we read the subject line!

Tired of sharpening knives by hand, [Joe] wanted to speed up the process. He recently saw our post on making a tool sharpening turntable out of a bread maker and figured, why not make one out of a bread slicer? We have no idea how you guys came up with these — finally some real hacks!

First he took apart the bread slicer and salvaged the motor, gears, and some of the electronics. He created an enclosure for it out of some laminate wood he had laying about and created a bearing axle for the disc from an old VCR. To control the speed he’s using a plain old light switch dimmer; not the most efficient but does the trick!

It uses sanding discs you can buy from any hardware store, and as you can see in the following video — it works pretty good according to the paper cutting test!


Filed under: tool hacks

We Have a Problem: Shower Feedback Loop

พฤ, 03/19/2015 - 06:01

Hackaday, we have a problem. Clean water is precious and we want to come up with some ideas to help conserve it. Today’s topic is water wasted while showering. Let’s kick around some ideas and prompt some new builds for The Hackaday Prize.

We’ve all done it; your mind wanders and before you know it you’ve been standing in the shower for far too long. How much water have you wasted? Who know’s, there’s no feedback loop in the shower. But we think adding a little bit of feedback is a fantastic avenue to help combat wasteful habits.

Color Changing Showerheads

What if the showerhead changed colors based on how much water had flowed through it? We’ve already seen consumer showerheads that have the LEDs inside of them, and flow meters are readily available. Start your shower off in the green, as you lather up the suds it moves through blue, purple, orange, red, and finally to flashing red. It doesn’t have to be annoying, but just enough to help quantify how much is pouring down the drain.

Shower Beats

We were big fans of the game SSX Tricky back in the day. The better you were at tricks, the better the music was. If you crashed hard, you’d be listening to nothing more than hi-hat and subdued bass. Apply this to shower time. What if that flow meter you installed on your shower head was connected to a shower radio? Start it off with the best music in the world and progress to the lamest as you run the reservoir dry (ymmv on these selections of course).

Now You Try

If you shave off 5 seconds from your shower it will have a tiny impact in your household. But imagine the aggregate of every household in the world doing so.

This is part of what the 2015 Hackaday Prize is all about. Get the idea machine rolling. Tell us your riff on the shower feedback loop in the comments below. Put up a new project on Hackaday.io, write down an idea, and tag it “2015HackadayPrize”. We’re on the lookout for the best seed ideas and will be giving away shirts and stickers to the ones that show real promise. We’ll be featuring some of these in future installments of “Hackaday, We Have Problem” and if we choose yours it’ll land you with some swag of your own.


Filed under: Hackaday Columns, The Hackaday Prize

Adding Recycling Codes To 3D Prints

พฤ, 03/19/2015 - 03:00

Every little plastic bauble you interact with has some sort of recycling code on it somewhere. Now that we’re producing plastic 3D printed parts at home, it would be a good idea to agree on how to recycle all those parts, and [Joshua Pearce]’s lab at Michigan Tech has the answer; since we’re printing these objects, we can just print the recycling code right in the object.

The US system of plastic recycling codes is particularly ill-suited for identifying what kind of plastic the object in question is made of; there are only seven codes, while China’s system of plastic identification uses 140 identification codes. This system for labeling 3D printed parts borrows heavily from the Chinese system, assigning ABS as ‘9’, PLA as ’92’, and HIPS as ‘108’.

With agreed upon recycling codes, the only thing left to do is to label every print with the correct recycling code. That’s an easy task with a few OpenSCAD scripts – the paper shows off a wrench made out of HIPS labeled with the correct code, and an ABS drill bit handle sporting a number nine. 3D printing opens up a few interesting manufacturing techniques, and the research team shows this off with a PLA vase with a recycle code lithophane embedded in the first few layers.


Filed under: 3d Printer hacks

Crazy Whirlwind Pre-Hackaday Prize Launch Tour

พฤ, 03/19/2015 - 00:01

The Hackaday Prize was about to launch but the date wasn’t public yet. I decided to do a pre-launch tour to visit a few places and to drop in on some of the Hackaday Prize Judges. It started in Chicagoland, looped through San Francisco for a hardware meetup and Hardware Con, then finished with visits to [Ben Krasnow’s] workshop, [Elecia White’s] studio, and the Evil Mad Scientist Laboratories.

The Prize is now running and it’s time for you to enter. Look at some of the awesome hacking going on at the places I visited and then submit your own idea to get your entry started. Join me after the break for all the details of the adventure.

Chi-town

Catalyze Chicago is a co-working space that focuses on hardware entrepreneurs, so of course I had to go there. Pictured is a drum set on the ceiling (right) that you can play from your phone.

Next up, Pumping Station : One. Hackaday co-hosted a meetup with PS1 and it was super fun. We all showed off our projects and did some quick talks. There were so many people with projects to show off that we stayed there well into the night. [Drew Fustini] broke the ice with his project, a merge of accelerometer and MicroView. This was followed by a whole slew of projects, from Nixie tubes (YEAH!) to [Ryan Pierce] beer brewing with control box labels from Argonne National Laboratory.

Also seen at Pumping Station : One, [Jason Kridner] of BeagleBoard.org and a 3D printer called SeeMeCNC which runs Machinekit. A huge and powerful 3D printed robot arm was shown which is controlled by a Myo gesture control band and then a project and lightening talk that started with “I quit my day job to make sensors for my wife, a geothermal engineer”. In the shot of the audience at Pumping Station, the man second from the right developed a bracelet that helps a woman with MS to use her phone. On the entertainment side of things, one interactive project I saw allowed the participants to access a local wireless network to play a fun game.

After Chicago, I headed for San Francisco, to get there just in time for the Hardware Developer’s Didactic Galactic, a meetup that takes place in the [Supplyframe] office once a month. This HDDG had two speakers, [James Whong] from Mooshimeter -makers of the the 600V, 10A, 24-bit meter + BLE / App for remote metering applications and [Mark Garrison] from Saleae, who spoke about manufacturing challenges with their logic analyzer.

 

Just as an aside but in San Francisco, there is wireless charging in Starbucks. So while you may be a Starbucks hater, the wireless charging they offer (and $1.90 coffee refills) makes it a good place to rest.

I got to visit Othermill, the unbelievably well engineered PCB milling machine (bottom). Othermill is located in the Felix F. Schoenstein and Sons building (top). [Simone Davalos] gave us the tour.

I also visited MAKE offices and saw Keepon, the little robot meant to entertain autistic children (left) on someone’s desk.

The next day was a PCB design workshop which went from 10am until 8pm, which made my head hurt (in a good way)!

HardwareCon3, a first year conference for Hardware based startups was in San Leandro, CA. It was held in a net-zero energy building which made for plenty of interesting decor. The conference itself was informative and entertaining both. Recommend!

I found a useful breakout shield for the Arduino Mega! Thanks [Ace Shelander] for the tester.

Hackaday Prize Judge Visits

The trip ended with a 2015 Hackaday Prize judge tour. First up: [Ben Krasnow]. After checking out the Delorian (seriously we looked inside and at the motor), we used his oscilloscope to look at hex data decoded from I2C lines. Other highlights and eye candy were a giant milling machine and…oh snap, caps.

Next judge that I visited was [Elecia White]. I got to see the famed Maxwell from her tutorial on Sparkfun. Besides writing embedded software and designing electronics, [Elecia] has a podcast called Embedded with [Chris White] and we recorded a Hackaday Prize teaser.

The last two Hackaday Prize Judges I visited were [Lenore Edman] and [Windell Oskay] , who co-own Evil Mad Scientist Laboratories in Sunnyvale, CA. There is the 555 timer footstool and some beautiful designs made with their Egg-bot, a CNC egg decorator.

A pizza party in Sunnyvale was the final end to the trip. [Kenneth Finnegan] showed us a small $50 radio and the conversation turned to communications in certain desert areas.

It was a hectic but fun week. Meeting so many of you and seeing so many very excellent projects in every place I went was inspiring. Let us know at prize@hackaday.com if you would like to co-host an event with us at your Hackerspace, restaurant, office, or launchpad.


Filed under: Featured, Hackerspaces, The Hackaday Prize

How to Directly Program an Inexpensive ESP8266 WiFi Module

พุธ, 03/18/2015 - 21:01

The ESP8266 is the answer to “I want something with Wifi.” Surprisingly, there are a number of engineers and hobbyists who have not heard of this chip or have heard of it but don’t really understand what it is. It’s basically the answer to everything IoT to so many engineering problems that have plagued the hobbyist and commercial world alike.

The chip is a processor with integrated RAM, some ROM, and a WiFi radio, and the only external components you will need are 4 capacitors, a crystal and an external flash! It’s CHEAP, like $4/ea cheap! Or $5 if you want it on a nice, convenient carrier board that includes all these components. The power consumption is reasonable (~200mA)1, the range is insane ~300m2 without directional equipment, and a PCB trace antenna and ~4km if you want to be ridiculous.

One place thing that more people need to know about is how to program directly for this chip. Too many times projects use it as a crutch via the AT commands. Read on and find out how to hello world with just this chip.

Know thy Hardware

First off, some background. Let’s start with a picture of it (decapped by zeptobars), and marked up by swimmmerdude.3

The processor by default runs at 80 MHz but can go up to 160 MHz, it has ~80kB DRAM (Data RAM), and ~35kB of high speed IRAM (Instruction RAM).4 Yes, that means it uses a Harvard architecture. The IRAM is loaded at boot with whatever the user wants to keep on-processor, though the processor can run code directly off of the external flash at a lower speed.

Firmware Background

By default when you buy these neat little boards, many of them come with the “AT” firmware, which is basically a really neat, easy, tool that lets you use these devices as simple wireless modems controlled through a serial port. That’s neat and all, but it is difficult to do particularly complicated things with this and as I mentioned before it requires the use of an external processor.

Two different ESP8266 modules

There are a few modes the chip can boot in based on the configuration of some GPIO pins. We won’t be discussing “SDCard startup” as most of the hobbyist community has not really taken to it, but we will be discussing Flash startup and UART download. Additionally, there is a remote firmware upload feature that has a few different revisions and possibilities, but we’ll save that for another post.

For the two modes we care about, the processor expects GPIO15 to low and GPIO2 to be high on boot. GPIO0 selects between the two modes we are going to discuss here. During normal operation, we would want to use a resistor to pull GPIO0 high.5 That will cause the bootloader inside the ESP8266 to read data from the EEPROM chip into the ESP8266’s IRAM and boot our program. If we set GPIO0 low, however, the boot ROM inside the ESP8266 takes over and it begins communicating over the UART. Using this boot ROM we can push our programs to the flash memory. A good way to make use of this is to connect a switch from GPIO0 to ground so you can put it into program mode at will by holding the button at power on.

This is surprisingly reliable and even supports different baud rates. I use 454,800 for my baud rate, so I can make modifications to my programs and test them very quickly. One of my projects takes less than a second to compile and about 8 seconds to burn. There are official tools to upload firmware “XTCOM”, however I personally like to use esptool.py6 because it lets you automate the flashing. Additionally, once it finishes flashing the chip, even if GPIO0 is tied low, it will cause your firmware to run. Then, if your code reboots, it will automatically re-enter the bootloader for another programming cycle. This means you can keep GPIO0 hooked to GND while you’re developing.

All in all, our development tools look like:

  • A switch from GPIO0 to ground (with a pull-up resistor to VCC)
  • GPIO2 and CH_PD connected to VCC
  • GPIO15 connected to ground
  • USB to TTL UART Adapter communicating with ESP8266 and providing 5V to the 3.3V regulator powering the chip

Btw… you can get USB to TTL-level UARTs super cheap, check out electrodragon for ones that are less than $1/ea!

Toolchains

Programming the ESP8266 is a little difficult to get off the ground with, but once you do, things are very easy. There are a few options for building the toolchain on Linux and OSX, plus some options in Windows. I’ve tried to keep a list of toolchains in my ws2812esp8266 readme as up-to-date as possible. Details about building the toolchain are outside of the scope of this how-to but follow that guide, or this possibly more up-to-date toolchain tutorial, and you should have no issues. Once you get a toolchain built and you can compile a firmware, like my WS2812ESP8266 firmware, you’ll be good to go for the rest of this article.

Espressif has been nice enough to distribute their SDK freely.7 This was something that absolutely shocked the community, in a good way! This was extremely generous and a move few companies make. The SDK contains an example, and headers for the ROM as well as Espressif’s library. It’s important to note that there is a community library, but every time I’ve used it so far it does not match the same level of maturity as the espressif library. Perhaps that’ll change in the future.

Be sure to check out the “include” folder in their SDK. This includes a lot of awesome functions to help get you from zero to hero in no time!

Programming: There’s a ROM for That

There’s a few things to take note of when programming the ESP8266. One is that there are a bunch of functions that are built into the ROM you can leverage. This means you don’t need to (and shouldn’t) re-implement MD5 (even with hmac), SHA1, comms with the external flash, SPI, UART functions, software floating point functions, AES, memory commands, printf, low-level IO tools, even a real-time event scheduler, and, most importantly… 802.11!

The full list of functions that reside in the on-chip ROM can be found in eagle.rom.addr.v6.ld. It would behoove you to take a look in there now and see the wonderland of awesome that’s provided out of the box.

In addition to the on-chip ROM, there’s more to their API that sits on top to make using this thing as easy as pie. We can see a number of facilitating tools. Because the ESP8266 can act as an access point or client (or both, though I’ve never tried), it has a number of tools you can use. By default the ESP8266 has it’s own unique AP. I.e. when you power it on out-of box and start their API, it starts in host-mode running its own DHCP server. You can find it by looking for a wifi network that starts with ESP8266.

Embrace Abstraction

If you’re looking to write main and have your own main loop, that’s not going to happen. While you can write main, the API expects to have its own main loop. In this sense, programming the ESP8266 is a lot like programming an Arduino.

static void ICACHE_FLASH_ATTR procTask(os_event_t *events) { system_os_post(procTaskPrio, 0, 0 ); printf( "Idle Task\n" ); } void user_init(void) { system_os_task(procTask, procTaskPrio, procTaskQueue, procTaskQueueLen); system_os_post(procTaskPrio, 0, 0 ); }

If you need events to happen at regular intervals, there are timer functions, os_timer_setfn, os_timer_arm that can call a function at a specific interval.

That’s great for the overall environment, however, we haven’t actually talked about how to do anything with this part. Let’s talk about how to use 802.11 with this. If you’re afraid, I don’t blame you. Trying to change 802.11 settings or connect to networks, etc is a scary proposition. Ever try doing it in Linux or Windows programatically? It’s terrifying. On the ESP8266, though, it’s easy!

Connect ESP8266 to AP in 8-lines of Code

Once your ESP8266 has booted, if something happens where it should connect to an existing network, write the following code and it’ll just happen:

const char ssid[32] = "my_home_ssid"; const char password[32] = "my_home_password"; struct station_config stationConf; wifi_set_opmode( STATION_MODE ); os_memcpy(&stationConf.ssid, ssid, 32); os_memcpy(&stationConf.password, password, 32); wifi_station_set_config(&stationConf); wifi_station_connect();

No, really, it’s just that easy. It’ll just connect to your AP, pull an IP and sit there. No fuss no muss. On top of that, it’ll remember this operation and next time you boot it, it’ll connect right up. When I’ve used it with a good AP, I was able to get it to connect, in about 2 seconds after boot. Yes, it’s really that fast.

Serving TCP

What about making a TCP server, something that can listen on a port and send back data? Surely that’s difficult. Nope. Here’s an example from an HTTP server I wrote for it:

//Allocate an "espconn" pHTTPServer = (struct espconn *)os_zalloc(sizeof(struct espconn)); ets_memset( pHTTPServer, 0, sizeof( struct espconn ) ); //Initialize the ESPConn espconn_create( pHTTPServer ); pHTTPServer->type = ESPCONN_TCP; pHTTPServer->state = ESPCONN_NONE; //Make it a TCP conention. pHTTPServer->proto.tcp = (esp_tcp *)os_zalloc(sizeof(esp_tcp)); pHTTPServer->proto.tcp->local_port = 80; //"httpserver_connectcb" gets called whenever you get an incoming connetion. espconn_regist_connectcb(pHTTPServer, server_connectcb); //Start listening! espconn_accept(pHTTPServer); //I don't know what default is, but I always set this. espconn_regist_time(pHTTPServer, 15, 0);

What about receiving the connections? Here’s how you do that:

//This function gets called whenever void ICACHE_FLASH_ATTR server_connectcb(void *arg) { int i; struct espconn *pespconn = (struct espconn *)arg; //espconn's have a extra flag you can associate extra information with a connection. pespconn->reverse = my_http; //Let's register a few callbacks, for when data is received or a disconnect happens. espconn_regist_recvcb( pespconn, http_recvcb ); espconn_regist_disconcb( pespconn, http_disconnetcb ); }

That’s it. Send data? espconn_sent. Close a connection? espconn_disconnect. Whenever you get data, it is passed in via the recv callback.

You’ve probably noticed I used the ICACHE_FLASH_ATTR directive, eh? Well, remember how we don’t have much IRAM? Doing this will keep the function on the flash. The instructions are cached but don’t take too long to load from the flash.

Working with GPIO

The last key point I will be covering in this article is GPIO. The pins have optional internal pull-up, and pull-down resistors. They can all be configured as inputs or outputs. There’s some utility functions for dealing with the GPIOs. You’ll need to call gpio_init(…) some are macros like PIN_PULLDWN_DIS(…), PIN_PULLUP_EN(…), and others found in the SDK. You can configure the input/outputs with gpio_output_set. Many of the GPIOs may have multiple functions, some of these functions are enabled by default, so, for instance, at boot you can’t do anything with GPIO12 and GPIO14 until they are selected as GPIO.

PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDI_U, FUNC_GPIO12); PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTMS_U, FUNC_GPIO14);

Learning to program the ESP8266 is like learning to program in any other environment. The header files provided with the SDK are very helpful when you’re trying to figure out what’s what, or to see if there’s some easy way to do what you want. So far, the data sheet hasn’t been all that helpful to me, however, Google has by far been the best tool for finding information on how to do something with this part.

The Community

Because this part really is the answer to so many problems, it has taken the hobbyist community by storm! Forums like esp8266.com and the Russian counterpart esp8266.ru are full of people trying to use the this part for awesome things! They’re full of people who have all been learning from each other about how to make the most of this little part.

Resources

[1] A general wiki for a lot of information surrounding this chip such as electrical characteristics, etc. Much of this is translated from the Chinese data sheets. https://nurdspace.nl/ESP8266

[2] Range tests I performed on the ESP8266. https://www.youtube.com/watch?v=7BYdZ_24yg0

[3] The reddit post where swimmmerdude gave his guesses at what the decapped chip looks like http://www.reddit.com/r/electronics/comments/2jq22l/esp8266_wifiserial_chip_decapped_its_actually/

[4] Memory map for address space, SPI Flash layout, registers including IOMUX: https://github.com/esp8266/esp8266-wiki/wiki/Memory-Map

[5] Discussion on the start modes of the ESP8266: http://www.esp8266.com/viewtopic.php?f=6&t=33

[6] The esptool.py site that contains information about uploading programs to the ESP8266 and alternative wiring schemes that can help with flashing. https://github.com/themadinventor/esptool/

[7] The official espressif post for the ESP SDK 0.9.5 http://bbs.espressif.com/viewtopic.php?f=5&t=154


Filed under: Featured, how-to, slider, wireless hacks

An Experiment In Shift Registers and Multiplexed LEDs

พุธ, 03/18/2015 - 18:00

[Kratz] is working on a WiFi controlled scoreboard, but before building the full-scale version, he thought it would be wise to test out the multiplexing technique for the display. The experiment worked, but unless this scoreboard is for a foosball table, he still has a lot of work ahead of him.

The design of this prototype display is pretty simple, with just two ‘595 shift registers feeding bits to the display. Sixteen NPN transistors are being used to sink and source current to the display. It’s a relatively simple circuit, allowing [Kratz] to fit nine seven-segment displays on a small board with only six wires – ground, two V+ for the logic and LEDs, clock, data, and latch – going to the microcontroller.

There were a few snags in the design; the data is clocked in on a rising edge, but an extra falling edge was required before latching. [Kratz] can’t figure out the reason for this, and it might just be a timing issue.


Filed under: led hacks

Excuse me, Sir. Do you know how fast your Lathe was traveling back there?

พุธ, 03/18/2015 - 15:01

When machining metal, it is important to know how fast the cutting tool is traveling in relation to the surface of the part being machined. This amount is called the ‘Surface Speed’. There are Surface Speed standards for cutting different types of materials and it is good practice to stick with those standards in order to end up with a good surface finish as well as maximizing tool life. On a lathe, for example, having a known target Surface Speed in mind as well as a part finish diameter, it is possible to calculate the necessary spindle speed.

Hobbyist [Paul] wanted a method of measuring his lathe’s spindle speed. Since spindle speed is measured in RPM, it made complete sense to install a tachometer. After browsing eBay for a bit he found one for about $20. His purchase came with the numeric LED display, a mounting bezel and the all important hall effect sensor. The Hall effect sensor measures changes in a magnetic field and in turn varies its output voltage. [Paul] fabbed up an aluminum bracket that supports the sensor just off of the rear of the lathe spindle. A magnet was then glued to the outside diameter of the spindle below the sensor. The once per revolution signal is generated every time the magnet passes the sensor while the lathe is running. The display was mounted to the lathe near eye height by means of another aluminum bracket and case.

After a little work, [Paul] can now keep a close eye on his spindle speed with a quick glance over at his new tachometer display while he’s turning those perfect parts! If this project tickles your fancy, you may want to check out this fantastic DIY tachometer or this one that uses a soundcard.


Filed under: tool hacks

Switchable Magnet with a Simple Circuit

พุธ, 03/18/2015 - 12:01

Magnets are awesome. Electromagnets are even cooler. But what if you could make a semi-permanent switchable magnet that acts like an electromagnet, but doesn’t use any energy to hold metal? You’re going to want to take a look at this Low-power Magnetic Hold and Release Mechanism.

It’s actually a very simple concept. It is basically an electromagnet attached to a permanent magnet — it’ll hold any metal object exactly as you’d expect — but if you run current through the inductor attached to it, the magnetic field created by the electricity will temporarily cancel out the field of the magnet — thus freeing your object being held. Since gravity is pretty fast acting, this impulse of current doesn’t need to be very long, only fractions of a second.

Now the real question is how big could you go? We covered another project a while ago called Open Grab which discusses the possibility of using technology like this in Quadcopters.

For a solution that uses no power at all take a look at switchable magnet clamps used for welding — they’re pretty cool — but patent protected of course.


Filed under: misc hacks

Putting new into the old – a Phonograph upgrade.

พุธ, 03/18/2015 - 09:01

[smellsofbikes] recently came into possession of a 1970’s “stereo radio phonograph” cabinet consisting of a vinyl record player, AM and FM radio, and eight track tape player. The radio worked, the turntable didn’t sound too nice, and the tape player didn’t work at all. A new needle fixed the turntable, but the eight-track was in bad shape. So he replaced the tape player with a BeagleBoneBlack which plays streaming internet radio.

Hopefully, this fix is temporary, since he has carefully disconnected the tape player connections in the hope of fixing it soon. The swap out involved a fair bit of engineering, so he’s split his build log into several bite sized chunks. The first step was to set up the BBB, upgrade it and add in all the network and audio related stuff. Audio on the BBB is available only via the HDMI port, but [smellsofbikes] had a USB soundcard handy, so the next step was setting that up. He installed mpg321 – the command line mp3 player and set it up to play music streaming from somafm. Next up was getting some scripts and programs to run automatically during system bootup. The final part of the setup was adding a WiFi router as a repeater connected to the BBB via an ethernet cable. He could have used a tiny WiFi USB dongle, but he already had the router lying around, and he wanted to dedicate USB to audio functions alone, and use the Ethernet port for Internet.

He then worked on identifying the wires that go from the tape player to the amplifier, spliced them, and hooked them up to the audio sound card on the BBB. With this done, the upgrade was more or less complete – the system played streaming music and stations could be switched remotely (via SSH to BBB). [smellsofbikes] reckoned it would be nice to use the existing controls in the phonograph cabinet to control the internet streaming music, instead of controlling it via a remote computer. The cabinet had 4 indicator lamps that indicated which track was being played and a button to switch between tracks. He removed the old indicator panel and put in a fresh PCB, designed in KiCad and cut on his LPKF circuit board plotter. An aluminum knob machined out of hex bar-stock works as the new track change button. At this point, he called it a wrap. The BBB and Asus router go inside the cabinet, and the old (non-functional) tape player is put in place. Quite an interesting build, and we look forward to when he actually gets the tape player working. [Alan Martin], aka “The Most Interesting Engineer In The World” has told him that “it is a moral imperative that you repair the eight-track and get it working”. [Alan] has promised to send [smellsofbikes] a suitcase full of brand new, still in their plastic wrappers, eight-track tapes when he gets it working.


Filed under: home entertainment hacks

SXSW Create: ATX Hackerspace Area

พุธ, 03/18/2015 - 06:01

We had a wonderful time over the weekend at the 2015 SXSW Create. I was really excited to see that there was a very large area set aside for the Hackerspaces of the Austin area and they took full advantage of that. Most notably, ATX Hackerspace who had multiple tables and was drawing a huge crowd.

This table is a good example of the demonstrations on hand. Primarily It’s a collection of ultrasonic theremin. The classic theremin uses oscillator-based sound production (we’ve been running a series on that concept) with a set of antennas that uses your body’s proximity to tweak that signal. This version mimics the user interface but greatly simplifies the skillset needed to produce the instrument by swapping the antenna for an ultrasonic rangefinder and generating the audio digitally. The more astute viewer will have noticed the instrument being held. I neglected to ask about this but it sure looks like a Holophonor which is another great seed idea for your next project. Update: it’s a Hulusi.

I do think it’s worth noting that ATX also set aside a lot of table-space for their members to actually work on building projects at the event. We’re big advocates of this rather than simply exhibiting finished projects. It doesn’t really matter what you’re working on; seeing a table covered with interesting parts and tools, being worked on by fun people obviously enjoy each other’s company is the core message of a Hackerspace… right?

I talk with [Gardner] about ATX in the video after the break, and make a quick loop around the display tables.


Filed under: cons, news

DIY Hololens Uses Pepper’s Ghost in a Box!

พุธ, 03/18/2015 - 03:01

Entirely too excited about Microsoft’s Hololens, the DIY community has leaped on the challenge to make some hardware before the real deal comes out. [Sean Hall] has an excellent 3D printed prototype that makes use of the Pepper’s Ghost illusion to create a “hologram” for this pair of unique VR goggles.

Similar to other DIY virtual reality goggles we’ve seen, [Sean] has 3D printed the enclosure — but instead of slapping the smart phone right in front of your eyes, it’s mounted above the goggles, reflecting off of a mirror and then a piece of transparent plexi-glass, which produces a hologram like effect thanks to the concept of Pepper’s Ghost illusion.

The problem with any of these reflection-based-holograms is they aren’t always that easy to see, so [Sean] is planning to try out some 1-way reflective car tint to get a more visible reflection while still being able to see through the image. He also plans to add gaze tracking with some open-source software called Project Haytham. It’s a depth sensor using a Kinect, head tracking using a Playstation Move and maybe even a leap motion controller for virtual object manipulation.

Check out the current state of this hack in the clip after the break.


Filed under: 3d Printer hacks, Virtual Reality

Retrotechtacular: On the Wings of Goodyear

พุธ, 03/18/2015 - 00:00

At the opposite end of the spectrum from the various blimp and rigid-hull airships Goodyear has created over the years stands the Goodyear Inflatoplane, the company’s foray into experimental inflatable aircraft. Goodyear had recently created a rubberized nylon material they called Airmat, the faces of which were connected internally by nylon threads. This material was originally developed during research into the viability of emergency airplane wings.

The United States military became interested in the Inflatoplane after Goodyear had performed successful testing of demonstration model GA-33. They believed that the Inflatoplane could be dropped from the air in a rigid container to facilitate an emergency rescue, or trucked around with the rest of the cargo as a last resort for just exactly the right situation. It seems like a good idea on paper. The Inflatoplane could stay packed into a fairly small container until it was needed. The GA-468 one-seater model could go almost 400 miles on 20 gallons of fuel, and required less pressure to inflate than the average car tire.

This episode of the Discovery Channel series WINGS includes a real-time demonstration of taking an Inflatoplane from crate to air set to late ’80s montage music. It takes the pilot a full five minutes to unfurl and  the plane, and he does it on a nice and level grassy spot by a lake that looks more like a cozy picnic spot than threatening enemy territory. While it’s better than not having an inflatable emergency aircraft, it just isn’t that practical.

Goodyear had all kinds of plans for future improvements, such as a vertical takeoff model and a rocket-powered version. But the Inflatoplane military initiative was grounded around the time that someone speaking for the Army deadpanned that they “could not find a valid military use for an aircraft that could be taken down by a well-aimed bow and arrow.”

Bonus video: wind tunnel testing at Langley

 

Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.


Filed under: Hackaday Columns, Retrotechtacular

Trace Your Book or Kindle with the FingerReader

อังคาร, 03/17/2015 - 21:00

[Roy Shilkrot] and his fellow researchers at the MIT Media Lab have developed the FingerReader, a wearable device that aids in reading text. Worn on the index finger, it receives input from print or digital text and outputs spoken words – and it does this on-the-go. The FingerReader consists of a camera and sensors that detect the text. A series of algorithms the researchers created are used along with character recognition software to create the resulting audio feedback.

There is a lot of haptic feedback built into the FingerReader.  It was designed with the visually impaired as the primary user for times when Braille is not practical or simply unavailable. The FingerReader requires the wearer to make physical contact with the tip of their index finger on the print or digital screen, tracing the line.  As the user does so, the FingerReader is busy calculating where lines of text begin and end, taking pictures of the words being traced, and converting it to text and then to spoken word. As the user reaches the end of a line of text or begins a new line, it vibrates to let them know. If a user’s finger begins to stray, the FingerReader can vibrate from different areas using two motors along with an audible tone to alert them and help them find their place.

The current prototype needs to be connected to a laptop, but the researchers are hoping to create a version that only needs a smartphone or tablet. The videos below show a demo of the FingerReader.  For a proof-of-concept, we are very impressed. The FingerReader reads text of various fonts and sizes without a problem. While the project was designed primarily for the blind or visually impaired, the researchers acknowledge that it could be a great help to people with reading disabilities or as a learning aid for English. It could make a great on-the-go translator, too. We hope that [Roy] and his team continue working on the FingerReader. Along with the Lorm Glove, it has the potential to make a difference in many people’s lives. Considering our own lousy eyesight and family’s medical history, we’ll probably need wearable tech like this in thirty years!

 

[via Reddit]

 


Filed under: wearable hacks

Brains Controlling Labyrinths Without Hands

อังคาร, 03/17/2015 - 18:00

[Daniel], [Gal] and [Maxim] attended a hackathon last weekend – Brainihack 2015 – that focused on neuroscience-themed builds in a day and a half long build off. The trio are communications systems engineering and computer science students with no background in neuroscience whatsoever. You can’t build an FMRI in a day and a half, so they ended up winning the best project in the open source category with a brain-controlled labyrinth game.

The labyrinth itself is entirely 3D printed and much, much simpler than the usual, ‘wooden maze with holes’ that’s generally associated with labyrinth puzzles. It’s really just a plastic spiral for a ball to follow. There’s a reason for this simplicity. The team is using EEG to detect brain waves and move the labyrinth on the X and Y axes.

The team is using OpenBCI for the interface between their brains and a pair of servos. This is actually an interesting piece of tech; unlike a few toys like the NeuroSky MindWave and the Star Wars Force Trainer, the OpenBCI gives you eight input channels that attach to anywhere on the scalp. The team used these inputs to measure Alpha waves and Steady State Visually Evoked Potential to control the pair of servos on the labyrinth frame.

It’s a great build, a wonderful demonstration of a device that outputs real EEG signals, and the team on a prize. What’s not to like?


Filed under: Medical hacks

Solar Charge Controller Improves Efficiency of Solar Panels

อังคาร, 03/17/2015 - 15:00

The simplest and easiest way to charge a battery with a solar panel is to connect the panel directly to the battery. Assuming the panel has a diode to prevent energy from flowing through it from the battery when there’s no sunlight. This is fairly common but not very efficient. [Debasish Dutta] has built a charge controller that addresses the inefficiencies of such a system though, and was able to implement maximum power point tracking using an Arduino.

Maximum power point tracking (MPPT) is a method that uses PWM and a special DC-DC converter to match the impedance of the solar panel to the battery. This means that more energy can be harvested from the panel than would otherwise be available. The circuit is placed in between the panel and the battery and regulates the output voltage of the panel so it matches the voltage on the battery more closely. [Debasish] reports that an efficiency gain of 30-40% can be made with this particular design.

This device has a few bells and whistles as well, including the ability to log data over WiFi, an LCD display to report the status of the panel, battery, and controller, and can charge USB devices. This would be a great addition to any solar installation, especially if you’ve built one into your truck.

This is [Debasish]’s second entry to The Hackaday Prize. We covered his first one a few days ago. That means only one thing: start a project and start documenting it on hackaday.io


Filed under: solar hacks, The Hackaday Prize

Brighten Your Day with Motion Controlled Cabinet Light

อังคาร, 03/17/2015 - 12:00

[Thomas Snow] found himself in a bit of a pickle. His kitchen lights didn’t adequately light his counter-tops. So instead of inventing a light bending device that could warp space-time enough to get the light where it needs to go, he decided to take the easy road and installed a motion controlled LED strip under the cabinets.

Now, these aren’t just any ‘ol motion control lights. Not only is [Thomas] able to turn the lights on and off with a wave of his hand, he can control the brightness as well. He’s doing the magic with an ultrasonic range sensor and PIR sensor. An ATTiny85 ties everything together to form the completed system.

The PIR sensor was incorporated because [Thomas] didn’t want to bug his pets with the 40kHz chirp from the ultrasonic sensor. So it only comes on when the PIR sensor sees your hand. Be sure to check out [Thomas’s] project for full source and schematics.


Filed under: ATtiny Hacks, home hacks

Mobile Lorm Glove Puts Texting Back Into Everyone’s Hands

อังคาร, 03/17/2015 - 09:00

If you’ve been killing time texting or chatting with your pals via smart phone, odds are pretty good that you’re not giving much thought to the two senses that make it happen: your sight and your hearing. Those who are deafblind, however, cannot participate in these activities; and for many, the remote communication that most of us enjoy with our phones simply isn’t possible. Enter Berlin University of the Arts Design Research Lab. Here, they’ve developed the Mobile Lorm Glove, a haptics device that enables two-way remote communication via smart phone.

For the deafblind, Lorm is the tactile technique for communication. Lorm is a series of hand-tracing gestures that map to characters of the alphabet. To communicate with others, the gloved user can trace Lorm directly onto the pressure-sensitive inputs on the palm of the hand. To receive messages, small vibration motors on the back of the hand vibrate to indicate the message encoded in Lorm.

Originally, to communicate with the deafblind, we must first learn Lorm. With the Mobile Lorm Glove, however, we need only know how to send text messages, and the Lorm-decoding is handled with a look-up table running on our classic Atmega328 microcontroller. For the sharp-eyed, the back-side of the glove seems limited in its capability to transcribe continuous finger traces into discrete motor vibrations. However, with four shift-registers and 32 levels of motor-intensities, the designers address each motor with a technique called “funneling illusion” where continuous movement is simulated by gradually changing the intensity from motor to motor. For more tricks and details, take a look at their conference paper.

By wearing the glove, everyday communication can be made far easier with anyone with a smart phone. We’re jazzed that just a Bluetooth module, an Atmega328, and a collection of pressure sensors and motors can enable any cell phone user to circumvent the learning curve and open up a new conversation.


Filed under: tool hacks, wearable hacks