Upgrading Old Synths To OLED

Roland’s Alpha Juno 2 is an analog, polyphonic synth made in the mid-80s. While it isn’t as capable as the massive synths made around that time, it was very influential synth for the techno scenes of the late 80s and early 90s.

[Jeroen] is lucky enough to have one of these synths, but like all equipment of this era, it’s showing its age. He wanted to replace the character LCD in his Alpha Juno 2 with an OLED display. The original character LCD was compatible with the Hitachi HD44780 protocol, and still today OLEDs can speak this format. What should have been an easy mod turned into editing hex values on the EEPROM, but he still got it to work.

While the original character LCD could display one line of 16 characters, the ROM in the synth didn’t know this. Instead, the display was organized as a 2×8 display in software, with line one starting at address 0h, and line two starting at 40h. For a drop-in replacement, [Jeroen] would need a display the characters organized in this weird 2×8 format. None exist, but he does have a hex editor and an EEPROM burner.

With the Alpha Juno’s firmware in hand thanks to someone who does a few firmware hacks to this synth, [Jeroen] had everything he needed. All that was left to do was going through the code and replace all the references to the second line of the character LCD.

After burning and installing the new ROM, the OLED display was a drop-in replacement. That meant getting rid of the whiney EL backlight in the original display, and making everything nice and glowy for a few nights on a dark stage.

The Stork Looks Different Than We Thought

What the Internet of Things really needs is more things, and the more ridiculous the better. At least, that’s the opinion of [Eric] who has created a tongue-in-cheek gadget to add to the growing list of connected devices. It’s a Bluetooth-enabled pregnancy test that automatically releases the results to the world. Feeling lucky?

The theory of operation is fairly straightforward. A Bluetooth low-energy module is integrated into the end of a digital pregnancy test. These tests have a set of photo detectors to read the chemical strip after the test is conducted. If the test is positive, the module sends a signal to a Raspberry Pi which tweets the results out for the world to see. It also has an option to send a text message to your mom right away!

[Eric]’s project to live-tweet a pregnancy test also resulted in a detailed teardown of a digital pregnancy test, so if you need any technical specifications for pregnancy tests (for whatever reason) his project site has a wealth of information. He does note that his device can be used on other similar devices with directly driven LCD screens, too. The fun doesn’t end there, though! Once the pregnancy is a little further along you’ll be able to get the baby on Twitter, too.

Continue reading “The Stork Looks Different Than We Thought”

Hackaday Links: January 10, 2016

Everybody loves cheap stuff, and we hate telling everyone about coupon codes. That said, TI has a new LaunchPad development board they’re promoting. It’s based on the MSP432, the ARM extension of their MSP430 line. The MSP432 is an ARM Cortex M4F, low power, and planned for production later this year.

Here’s your daily CES garbage post. Through a collaboration between Sony and Nissan, a car has become a video game controller controller. A controller plugs into the ODB II port, reads throttle, brake, and steering wheel positions (and buttons on the dash/steering wheel, I guess), and translates that into controller input for a PlayStation 4. What games do they play with a car? You would think Gran Turismo, Rocket League, or other games with cars in them. Nope. Football.

Dangerous Prototypes is a legal Chinese company! [Ian] didn’t say anything about the process about becoming a legal Chinese company because he wrote a blog post, not a book. Shenzhen Dangerous Prototypes Electronics Technology Limited allows them to have an office in the Shenzhen electronics market, hire local and foreign hackers, host Hacker Camp Shenzhen, and allow people to apply for ‘Authorized Authority’ visa letters for the people who need them. Great news for a great company.

The Forge hackerspace in Greensboro, NC is growing. In just over a year they have 160 members and they’ve already outgrown their 3,400 square foot space. Now they’re moving to a larger space that’s twice the size and they’re looking for donations.

People have been taking old iPad screens and turning them into HDMI displays for years now. [Dave] got his mitts on a panel from a Macbook Pro 17″, and turned it into a monitor. It required a $50 LVDS adapter, but the end result is great – a 1920×1200 panel that looks pretty good.

Better 3D Graphics On The Arduino

There are cheap LCDs available from China, and when plugged into an Arduino, these displays serve as useful interfaces or even shinier baubles for your latest project. [Michael] picked up a few of these displays in the hope of putting a few animated .GIFs on them. This is an impossible task with an ATMega microcontroller – the Arduino does not have the RAM or the processing power to play full-screen animations. It is possible to display 3D vector graphics, with an updated graphics library [Michael] wrote.

The display in question uses the ILI9341 LCD driver, found in the Adafruit library, and an optimized 3D graphics driver. Both of these drivers have noticeable flicker when the animation updates, caused by the delay between erasing a previous frame and when a new frame is drawn.

With 16-bit color and a resolution of 320×240 pixels, there simply isn’t enough memory or the processing power on an ATMega microcontroller to render anything in the time it takes to display a single frame. There isn’t enough memory to render off-screen, either. To solve this problem, [Michael] built his render library to only render pixels that are different from the previous frame.

Rendering in 3D presents its own problems, with convex surfaces that can overlap themselves. To fix this, [Michael]’s library renders objects from front to back – if the pixel doesn’t change, it doesn’t need to be rendered. This automatically handles occlusions.

In a demo application, [Michael]’s LCD and Arduino can display the Stanford bunny, a low-poly 3D face, and geometric object. It’s not a video game yet, but [Michael] thinks he can port the classic game Spectre to this platform and have it run at a decent frame rate.

Video of the demo below.

Continue reading “Better 3D Graphics On The Arduino”

Hacklet 88 – Projector Projects

Everyone loves a big screen TV. Back in the old days, anything over 27 ” was considered big. These days if you’re not sporting at least 50″, you’ll end up with display envy. One thing hasn’t changed though, those who want to go really, really big get into projectors. Hacking and projectors seem to go hand in hand. Anyone else remember those old DIY projection setups where the user would put their TV in a box upside down? This week’s Hacklet is all about projector hacks!

hushWe start with [Chaz] with Projector Hush Box . [Chaz] had a good projector, but still found himself with a problem. Projectors generate a lot of heat, which is dissipated via a fan. For whatever reason, projector companies seem to pick the loudest fans available. [Chaz’s] solution is to put the projector inside a box. Done right, this makes for a quiet projector. Done wrong, it makes an oven. [Chaz] projector hasn’t caught fire yet, so we think he did it right. Two quiet and efficient PC fans direct air through the box, and around baffles which keep the noise down. An anti-reflective coated glass window lets the light out but keeps the noise in. Sound deadening foam helps cut the sound down even further.

led-projNext up is [ric866] with 100w LED projector conversion. The killer with projectors these days are the bulbs. In some cases it’s more cost-effective to buy a new projector than to replace the bulb in an aging one. That’s how [ric866] ended up with a pair of old NEC projectors – one with a working bulb, and one without. Bulbs for this model aren’t cheap at £100. [ric866] found a cheap replacement in a 100 Watt LED. The LED in question only cost £8.99 from everyone’s favorite auction site. LEDs may be efficient, but anyone who’s played with powerful LEDs can tell you they still get hot. [ric866] had to cut up the projector’s case a bit to fit in a heat sink and fan. He also had to spend some time bypassing the various case interlock switches. The final products color calibration looks to be a bit off, but not too shabby for a quick mod!

baffle[Tom_VdE] is serious about recycling. He isn’t one to let an old laptop go to waste when it can be turned into a projector! Remember the “TV in a box” kit we mentioned up in the title? This is the modern version of that same idea. [Tom] tore down the laptop’s LCD and placed it in a CRT monitor case with the appropriate lenses. A setup like this needs length, and focus adjustments. [Tom] managed all that by building a collapsible baffle out of plywood. A build like this needs a lot of light, so [Tom] is using a 100 Watt LED (or two). A water cooling system will keep the LED’s from melting down. [Tom] is still in the prototype phase, but we can’t wait to see his first movie night with this upcycled laptop.

sensorcalFinally, we have [Alex] who built Automatic projector calibration, project #161 on Hackaday.io. [Alex] took his inspiration from [Johnny Chung Lee] to build a system which can map a projector to any angle, size, or position. The secret is phototransistors embedded in the corners of a rectangular piece of foamboard. An Arduino reads the phototransistors while the projector runs a calibration routine. [Alex] switched over to a scanning line from [Johnny’s] original binary pattern. The scan isn’t quite as fast as the binary, but it sure looks cool. Once the positions of the sensors are known, it’s just a matter of mapping the entire screen to a smaller piece of real estate. Toss in a few neat transitions, and you’ve got an awesome demo.

If you want to see more projector projects, check out our new projector project list! If I missed your project, don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

What to Do with Old LCD Screens: Hack Your Own Electrochromatic Glass

There’s something decidedly science fiction-like about electrochromatic glass. A wave of a hand or a voice command and the window goes dark (or goes transparent). You can get glass like this today or you can add (pricey) film to existing glass, if you prefer.

[Artem Litvinovich] thought about using LCDs as window panes twenty years ago, but the cost was, of course, prohibitive. He recently realized that he had easy access to LCDs out of broken laptops and decided to see if it would be useful as a small window.

Continue reading “What to Do with Old LCD Screens: Hack Your Own Electrochromatic Glass”

Driving a 7 Segment LED Display From An FT232

Sometimes, a good hack is about using less rather than more. That’s the case with this neat tutorial from [Rahul.S] on driving a 7-segment LED display with an FT232. By using this cheap USB to serial controller, [Rahul.S] was able to drive the display directly without using a microcontroller, which keeps the component cost down.

He’s bit banging an octal buffer connected to the display. You may be surprised to find that the FT232 chips do have enough outputs to make this work. Rather than send serial data number to the display and have a controller convert this into a set of signals that make the number, this conversion is done by the PC, which then sends a signal that directly illuminates the appropriate parts of the LED. By using all of the available output lines of the FT232 (including ones like the RTS/CTS line that are usually used for signalling), [Rahul.S] was able to drive all seven of the elements and the decimal point.

Of course, cynics may argue that it would be simpler to use a cheap serial LCD display. That is true, but there is always something to be said for knowing how to do something yourself rather than letting others do it for you… Continue reading “Driving a 7 Segment LED Display From An FT232”