Color TV Broadcasts Are ESP8266’s Newest Trick

March 1, 2016 by 39 Comments

The ESP8266 is well known as an incredibly small and cheap WiFi module. But the silicon behind that functionality is very powerful, far beyond its intended purpose. I’ve been hacking different uses for the board and my most recent adventure involves generating color video from the chip. This generated video may be wired to your TV, or you can broadcast it over the air!

I’ve been tinkering with NTSC, the North American video standard that has fairly recently been superseded by digital standards like ATSC. Originally I explored pumping out NTSC with AVRs, which lead to an entire let’s learn, let’s code series. But for a while, this was on the back-burner, until I decided to see how fast I could run the ESP8266’s I2S bus (a glorified shift register) and the answer was 80 MHz. This is much faster than I expected. Faster than the 1.41 MHz used for audio (its intended purpose), 2.35 MHz used for controlling WS2812B LEDs or 4 MHz used to hopefully operate a reprap. It occasionally glitches at 80 MHz, however, it still works surprisingly well!

The coolest part of using the chip’s I2S bus is the versatile DMA engine connected to it. Data blocks can be chained together to seamlessly shift the data out, and interrupts can be generated upon a block’s completion to fill it in with new data. This allows the creation of a software defined bitstream in an interrupt.

Why NTSC? If I lived in Europe, it would have been PAL. The question you’re probably thinking is: “Why a dead standard?” And there’s really three reasons.

Continue reading “Color TV Broadcasts Are ESP8266’s Newest Trick” →

Breaking Out The ATtiny10

March 1, 2016 by 24 Comments

Atmel’s ATtiny10 is the one microcontroller in their portfolio that earns its name. It doesn’t have a lot of Flash – only 1 kilobyte. It doesn’t have a lot of RAM – only thirty two bytes. It is, however, very, very small. Atmel stuffed this tiny microcontroller into an SOT-23 package, more commonly used for surface mount transistors. It’s small, and unless your ideal application is losing this chip in your carpet, you’re going to need a breakout board. [Dan] has just the solution. He could have made this breakout board smaller, but OSHpark has a minimum size limit. Yes, this chip is very, very small.

Because this chip is so small, it doesn’t use the normal in-system programming port of its larger brethren. The ATtiny10 uses the Tiny Programming Interface, or TPI, which only requires power, ground, data, clock, and a reset pin. Connecting these pins to the proper programming header is easy enough, and with a careful layout, [Dan] fit everything into a breakout board that’s a hair smaller than a normal 8-pin DIP.

The board works perfectly, but simply soldering the ATtiny10 to a breakout board and using it as is probably isn’t the best idea. The reason you use such a small microcontroller is to put a microcontroller into something really, really small like ridiculous LED cufflinks. A breakout board is much too large for a project like this, but SOT23 test adapters exist, and they’re only $25 or so.

Either way, [Dan] now has a very, very small microcontroller board that can fit just about anywhere. There’s a lot you can do with one kilobyte of Flash, and with an easy way to program these chips, we can’t wait to see what [Dan] comes up with.

Boldport Tribute To Bob Pease

March 1, 2016 by 33 Comments

We have lost something in PCB design over the last few decades. If you open up a piece of electronics from the 1960s you’ll see why. A PCB from that era is a thing of beauty, an organic mass of curving traces, an expression of the engineer’s art hand-crafted in black crêpe paper tape on transparent acetate. Now by comparison a PCB is a functional drawing of precise angles and parallel lines created in a CAD package, and though those of us who made PCBs in both eras welcome the ease of software design wholeheartedly we have to admit; PCBs just ain’t pretty any more.

It doesn’t have to be that way though. Notable among the rebels are Boldport, whose latest board, a tribute to the late linear IC design legend [Bob Pease], slipped out this month. They use their own PCBmodE design software to create beautiful boards as works of art with the flowing lines you’d expect from a PCB created the old-fashioned way.

The board itself is an update to an earlier Boldport design, and features Pease’s LM331 voltage to frequency converter IC converting light intensity to frequency and flashing an LED. It’s one of the application circuits from the datasheet with a little extra to drive the LED. Best of all the kit is a piece of open-source hardware, so you can find all its resources on GitHub.

We are fans of Boldport’s work here at Hackaday, and it should come as no surprise that we have featured them before. From one of their other kits through several different pieces of PCB wall art, to their work making an appearance in Marie Claire magazine they have graced these pages several times, and we hope this latest board will be one of many more.

Very Pretty Gimbal With Long Feature List

February 29, 2016 by 15 Comments

What can you do when you have a nice CNC machine, but build beautiful things like this 3-axis gimbal? We covered some of [Gal]’s work before, and he does not subscribe to the idea that hacks should look like hacks. If you’re going to spend hours and hours on something, why not make it better looking than anything you could buy off-the-shelf.

The camera is held stationary with three hollow shaft gimbal motors with low cogging. We weren’t aware of hollow shaft motors, but can think of lots of sensor mounts where such a motor could be used to make very compact and smooth sensor mounts instead of the usual hobby servo configuration. The brains are an off-the-shelf gimbal controller. The gimbal has a DB9 port at the back which handles charging of the internal LiPo batteries as well as giving him a place to input R/C signals for manual control.

The case is made from CNC’d wood and aluminum. There are lots of nice touches. For example, he added two buttons so he could fine tune the pitch of the gimbal. Each button is individually engraved with an up/down arrow.

[Gal] reverse engineered the connector on Garmin action camera he’s using so he can keep it powered, stream video, or add an external mic. Next he built a custom 5.8Ghz video transmitter based on a Boscam module. The transmitter connects to the DB9 charging port on the gimbal.

It’s very cool when someone builds something for themselves that’s far beyond anything they could buy. A few videos of it in operation after the break.

Continue reading “Very Pretty Gimbal With Long Feature List” →

Fake Window Brings Natural Light Into Basement

February 29, 2016 by 27 Comments

Do you have a depressing basement? Maybe you still live with the parents? You need a fake window to cheer things up! As it turns out, it’s pretty easy to make a convincingly real-looking day-light window — plus you could totally mess with your circadian rhythm!

[thatdbeagoodbandname] has an office in his basement with no windows, which is why he set out to brighten up the room with this project. Apparently you can buy fake LED windows, but they’re expensive and don’t look that good. His goal was to build a cartoony “classic” window that would feel bright and uplifting — and to keep it well under $200.

In the end he ended up buying everything he needed from Home Depot for his project; some 2 x 4’s for the frame, a sheet of acrylic, and a set of LED plant grow-lights. Continue reading “Fake Window Brings Natural Light Into Basement” →

Design Analysis: Core XY Vs H-Bot

February 29, 2016 by 26 Comments

Hackaday writer [Joshua Vasquez] wrote about the mechanical difference between the Core-XY and H-Bot movements commonly used in 3D printers on his personal website. There are so many things a beginning mechanical designer can overlook when setting out to make a movement. Sometimes,in the case of these movements, they aren’t readily apparent, and like finding a troublesome pattern in code; have to be shown before the mind picks them up in future designs.

[Joshua] starts by describing how each movement works. At first glance, the H-Bot movement seems simpler and more effective than the Core-XY.  The Core-XY uses more belting, and some of the pulleys are out of plane with each other. However, this is done to eliminate a moment put on the frame in the H-Bot design. This moment can throw off the accuracy of the movement in unpredictable ways.

The Core-XY movement is one of our favorites. It keeps the motors stationary. It’s compact, precise, repeatable, and linear. It’s good to understand the mechanical reasons for this. Just like learning the SQL database calls a library has been obfuscating for you lets you write better code.

Build Your Own Sensor Skin

February 29, 2016 by 25 Comments

Scientific research, especially in the area of robotics, often leverages cutting-edge technology. Labs filled with the latest measurement and fabrication gear are unleashed on the really tough problems, like how to simulate the exquisite sensing abilities of human skin. One lab doing work in this area has taken a different approach, though, by building multi-functional sensors arrays from paper.

A group from the King Abdullah University of Science and Technology in Saudi Arabia, led by [Muhammad M. Hussain], has published a fascinating paper that’s a tour de force of getting a lot done with nothing. Common household items, like Post-It notes, kitchen sponges, tissue paper, and tin foil, are used to form the basis of what they call “paper skin”. Fabrication techniques – scissors and tape – are ridiculously simple and accessible to anyone who made it through kindergarten.

They do turn to a Circuit Scribe pen for some of their sensors, but even this nod to high technology is well within their stated goal of making it possible for anyone to fabricate sensors at home. The paper goes into great detail about how the sensors are made, how they interact, and how they are interfaced. It’s worth a read to see what you can accomplish with scraps.

For another low-tech paper-based sensor, check out this capacitive touch sensor keyboard.

Thanks for the tip, [Mattias]