Reverse Engineer then Drive LCD with FPGA

Fans of [Ben Heck] know that he has a soft spot for pinball machines and his projects that revolve around that topic tend to be pretty epic. This is a good example. At a trade show he saw an extra-wide format LCD screen which he thought would be perfect on a pinball build. He found out it’s a special module made for attaching to your car’s sun visor. The problem is that it only takes composite-in and he wanted higher quality video than that offers. The solution: reverse engineer the LCD protocol and implement it in an FPGA.

This project is a soup to nuts demonstration of replacing electronics drivers; the skill is certainly not limited to LCD modules. He starts by disassembling the hardware to find what look like differential signaling lines. With that in mind he hit the Internet looking for common video protocols which will help him figure out what he’s looking for. A four-channel oscilloscope sniffs the signal as the unit shows a blue screen with red words “NO SIGNAL”. That pattern is easy to spot since the pixels are mostly repeated except when red letters need to be displayed. Turns out the protocol is much like VGA with front porch, blanking, etc.

With copious notes about the timings [Ben] switches over to working with a Cyclone III FPGA to replace the screen’s stock controller. The product claims 800×234 resolution but when driving it using those parameters it doesn’t fill the entire screen. A bit more tweaking and he discovers the display actually has 1024×310 pixels. Bonus!

It’s going to take us a bit more study to figure out exactly how he boiled down the sniffed data to his single color-coded protocol sheet. But that’s half the fun! If you need a few more resources to understand how those signals work, check out one of our other favorite FPGA-LCD hacks.

Continue reading “Reverse Engineer then Drive LCD with FPGA”

A SEGA Dreamcast Controller With a Built-in Screen

[Fibbef] was hard at work on a project for a build-off competition when he accidentally fried the circuit board. Not one to give up easily, he opted to start a new project with only two days left in the competition. He managed to modify a SEGA Dreamcast controller to hold a color screen in that short amount of time.

The Dreamcast controller’s shape is somewhat conducive to this type of mod. It already has a small window to ensure the view of the visual memory card is not obstructed. Unfortunately [Fibbef’s] screen was a bit too large for this window. That meant he would have to expand the controller and the circuit board.

After taking the controller apart, he desoldered the memory card connectors. He then cut the circuit board cleanly in half vertically. He had to re-wire all of the traces back together by hand. It turned out initially that he had messed something up and accidentally fried the right half of the controller. To fix it, he cut a second controller in half and soldered the two boards together.

With some more horizontal space to work with on the PCB side of things, [Fibbef] now needed to expand the controller’s housing. He cut the controller into several pieces, making sure to keep the start button centered for aesthetics. He then used duct tape to hold popsicle sticks in place to make up for the missing pieces of the case. All of the sticks were then covered with a thick layer of ABS cement to make for a more rigid enclosure. All of this ended up being covered in Bondo, a common trick in video game console mods. It was then sanded smooth and painted with black primer to make for a surprisingly nice finish.

The screen itself still needed a way to get power and a video signal. [Fibbef] built an adapter box to take both of these signals and pass them to the controller via a single cable. The box as a USB-A connector for power input, and a composite connector for video. There’s also a USB-B connector for the output signals. [Fibbef] uses a standard printer USB cable to send power and video signals to the controller. The end result looks great and serves to make the Dreamcast slightly more portable. Check out the demo video below to see it in action. Continue reading “A SEGA Dreamcast Controller With a Built-in Screen”

Dedicated Automobile Traffic Monitor with Raspberry Pi

[j3tstream] wanted an easier way to monitor traffic on the roads in his area. Specifically, he wanted to monitor the roads from his car while driving. That meant it needed to be easy to use, and not too distracting.

[j3tstream] figured he could use a Raspberry Pi to run the system. This would make things easy since he’d have a full Linux system at his disposal. The Pi is relatively low power, so it’s run from a car cigarette lighter adapter. [j3tstream] did have to add a custom power button to the Pi. This allows the system to boot up and shut down gracefully, preventing system files from being corrupted.

After searching eBay, [j3tstream] found an inexpensive 3.2″ TFT LCD touchscreen display that would work nicely for displaying the traffic data. The display was easy to get working with the Pi. [j3tstream] used the Raspbian linux distribution. His project page includes a link to download a Raspbian image that already includes the necessary modules to work with the LCD screen. Once the image is loaded, all that needs to be done is to calibrate the screen using built-in operating system functions.

The system still needed a data connection. To make things simple and inexpensive, [j3tstream] used a USB WiFi dongle. The Pi then connects to a WiFi hot spot built into his 4G mobile phone. To view the traffic map, [j3tstream] just connects to a website that displays traffic for his area.

The last steps were to automate as much as possible. After all, you don’t want to be fumbling with a little touch screen while driving. [j3tstream] made some edits to the LXDE autostart file. These changes automatically load a browser in full screen mode to the traffic website. Now when [j3tstream] boots up his Pi, it automatically connects to his WiFi hotspot and loads up local traffic maps.

NeXT Cubes And LCD Monitors

The NeXT slabs and cubes were interesting computers for their time, with new interesting applications that are commonplace today seen first in this block of black plastic. Web browsers, for example, were first seen on the NeXT.

Running one of these machines today isn’t exactly easy; there are odd video connectors but you can modify some of the parts and stick them in an LCD monitor. It’s a tradeoff between a big, classic, heavy but contemporary CRT and a modern, light, and efficient LCD, but it’s still a great way to get a cube or slab up and running if you don’t have the huge monitor handy.

The NeXT cube doesn’t have a single wire going between the computer and the monitor; that would be far too simple. Instead, a NeXT Sound Box sits between the two, providing the user a place to plug the monitor, keyboard, mouse, and audio connectors into. [Brian] took the board from this Sound Box and put it inside an old NEC LCD monitor he had sitting around. 12V and 5V rails were wired in, the video lines were wired in, and [Brian] created a new NeXT monitor.

There are two versions of the NeXT Sound Box – one for ADB peripherals (Apple IIgs and beige Macs), and another for non-ADB peripherals. [Brian] also put together a tutorial for using non-ADB peripherals with the much more common ADB Sound Board.

Learning I2C with the Bus Pirate

When an air quality display project needed a display, [Inderpreet] looked into small character-based LCDs. [Inderpreet’s] chosen LCD used an I2C interface, which was new to him. Rather than shy away, [Inderpreet] grabbed his Bus Pirate and dove in!

I2C or Inter-Integrated Circuit serial interfaces are often mentioned here on Hackaday. They generally are easy to use, but as with all things, there are little gotchas which can make the road a bit more bumpy the first time you travel it. One of those things is voltage interfacing – I2C uses bidirectional open drain lines, so interfacing 3.3 V and 5V circuits requires a voltage level shifter circuit designed to handle that requirement. Thankfully in [Inderpreet’s] case, both his TI launchpad target devboard and the LCD used 3.3 volt logic levels.

buspirate2Before using the TI though, [Inderpreet] wanted to test with the Bus Pirate first. This would allow him to verify the hardware, and to make sure he was correctly using the I2C bus. The Bus Pirate can operate at 3.3V or 5V logic levels, and has on-board programming specific to the I2C bus. Controlling the Bus Pirate is as easy as hooking up a serial terminal program and plugging in a USB cable.

The I2C bus protocol is relatively simple, but can still be confusing to a new user. Each transaction needs an address, read/write bit, and a start command sent in the proper sequence before the data bytes can begin flowing. There are also acknowledge bits which prove that the data bytes are actually being received by the LCD. The Bus Pirate made all this easy, allowing [Inderpreet] to quickly display “Hello” on his LCD module.

The I2C bus is just the tip of the iceberg for the Bus Pirate. If you’re interested in learning more, check it out over at The Hackaday Store!

[via Dangerous Prototypes]

Making a Player Piano Talk MIDI

[Ramon] was always fascinated with pianos, and when he came across a few player piano rolls in an antique shop, a small kernel of a project idea was formed. He wondered if anyone had ever tried to convert a player piano into a full MIDI instrument, with a computer tickling the ivories with a few commands. This led to one of the best builds we’ve ever seen: a player piano connected to a computer.

[Ramon] found an old piano in Craigslist for a few hundred dollars, and once it made its way into the workshop the teardown began. Player pianos work via a vacuum, where air is sucked through a few pin points in a piano roll with a bellows. A series of pipes leading to each key translate these small holes into notes. Replicating this system for a MIDI device would be impossible, but there are a few companies that make electronic adapters for player pianos. All [Ramon] would have to do is replicate that.

The lead pipes were torn out and replaced with 88 separate solenoid valves. These valves are controlled via a shift register, and the shift registers controlled by an ATMega. There’s an astonishing amount of electronic and mechanical work invested in this build, and the finished product shows that.

As if turning an ancient player piano into something that can understand and play MIDI music wasn’t enough, [Ramon] decided to add a few visuals to the mix. He found a display with a ratio of 16:4.5 – yes, half as tall as 16:9 – and turned the front of the piano into a giant display. The ten different styles of visualization were whipped up in Processing.

display

The piano has so far been shown at an interactive art exhibit in Oakland, and hopefully it’ll make it to one of the Maker Faires next year. There are also plans to have this piano output MIDI with a key scanner underneath all the keys. Very impressive work.

Video below.

Continue reading “Making a Player Piano Talk MIDI”

Trinket EDC Contest Entry: Can I Borrow a Feeling?

We got a case of the Mondays just reading about [Sascha]’s work environment. Get this: every morning, first thing, the whole team gets together to check in and share how they’re all feeling. And they can’t even be candid about it—there’s actually an approved list of feeling descriptors, both good and bad. It’s an admittedly big list that includes, interestingly enough, both ‘tortured’ and ’embarrassed’. Yeah. We think something like group t’ai chi on the roof each morning sounds a lot more relaxing. Since [Sascha] is between a rock and a hard place on this one, it was time to let chance take over. He raised his HaD-imprinted Trinket skyward and Can I Borrow a Feeling? was born.

The gist is simple: [Sascha] abstracts his disposition out to either ‘good’ or ‘bad’ and pushes the corresponding button. The Trinket accesses an array and returns a randomly selected feeling to the LCD. Since the official list of feelings is about 300 words long, [Sascha] has to push the data into PROGMEM. He used good old Excel to split the list in twain, and her formulas came in very handy for centering the result on the LCD. Once [Sascha] knew how it would all fit together, he designed a cool enclosure in CorelDRAW and turned on the laser cutter. See the Spreadsheet of Acceptable Words for yourself on GitHub, and pick up the code and enclosure file while you’re there.

There’s still time to enter the Trinket Everyday Carry Contest.  The main contest runs until January 2, but we’re having random drawings every week! Don’t forget to write a project log before the next drawing at 9pm EST on Tuesday, December 30th. You and all of the other entrants have a chance to win a Teensy 3.1 from The Hackaday Store!