A tiny TV that shows weather, news, and the classic test pattern.

Tiny TV Tells The Temperature Tale

October 13, 2021 by Kristina Panos 3 Comments

Once upon a time, we would run home from the bus stop to watch Gargoyles and Brady Bunch reruns on the family TV, a late-1970s console Magnavox number that sat on the floor and was about 50% more cabinet than CRT. The old TV, a streamlined white Zenith at least ten years older, had been relegated to the man cave in the basement. It looked so mod compared to the “new” TV, but that’s not the aesthetic my folks were after. They wanted their electronics to double as furniture.

This little TV is a happy medium between the two styles, and for us, it’s all about those feet. But instead of cartoons, it switches between showing the current weather and the top news headlines. Inside that classy oak cabinet is an LCD, an ESP32, and an SD card module. The TV uses OpenWeatherMap and pulls the corresponding weather image from the SD card based on time of day — light images for day, and dark images for night.

We love that it shows the SMPTE color bars, aka the standard American TV test pattern as it switches between weather and news. After showing the top headlines, it automatically switches back to the weather channel. Be sure to check out the short demo video after the break.

Do you like your tiny televisions in strange places? Here’s one you can use to trim your tree this year.

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Banish Early Morning Zombification With The Zom-b-gone!

September 17, 2021 by Dave Rowntree 5 Comments

[Applied Procrastination] aka [Simen E. Sørensen] has a simple project to help those of us that struggle with early-morning zombification. By leveraging the backlight optics from a broken LCD monitor, it is possible to create an excellent diffused light source to simulate daylight, before your chosen waking time. The theory is that it is less shocking to the brain to be woken more gradually than an alarm may do. The increasing light level is to prepare the brain with a slowly increasing light level, reminiscent of daybreak, before being properly awoken by an alarm, regardless of the actual light level outdoors. This particularly useful for those of us in more northern regions, such as [Simen]’s native Norway, where mornings are very dark in the winter months.

Daylight is not purely a diffuse source however, it depends on the degree of atmospheric scattering, local reflections and such, but as far as we’re concerned here, we can just aim for as diffuse a light source a possible.

The implementation makes use of the existing LCD metal frame, the light guide panel (usually a big hunk of acrylic covered in etched markings on one side) the diffuser/brightener sheet, and the prism sheet. A white LED strip mounted around the frame edge directs light into the light guide, which with a combination of total internal reflection and scattering on one side only, effectively turns the light through 90 degrees, and spreads it out evenly across that surface. The result of this optical sandwich is flat, even light, exactly what you want for a display, and also for simulating daylight.

Nestled beneath the expected 3D printed frame, is a custom PCB derived by smooshing together the designs from the Adafruit DS3231 RTC module and the Arduino Nano, an additional push button and rotary encoder complete the minimalistic UI, and allow the device to double up as general purpose lamp during the day. Despite a few wobbles with assembling the frame, and some incorrect PCB footprinting, the whole thing came together pretty nicely. This is a perfect thing to do with broken LCD monitors, eeking out a new life and keeping the amount of landfill to a minimum.

For further details of the hardware and codes, see the Zom-b-Gone Github.

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Custom Instrument Cluster For Aging Car

August 1, 2021 by Bryan Cockfield 32 Comments

All of the technological improvements to vehicles over the past few decades have led to cars and trucks that would seem borderline magical to anyone driving something like a Ford Pinto in the 1970s. Not only are cars much safer due to things like crumple zones, anti-lock brakes, air bags, and compulsory seat belt use, but there’s a wide array of sensors, user interfaces, and computers that also improve the driving experience. At least, until it starts wearing out. The electronic technology in our modern cars can be tricky to replace, but [Aravind] at least was able to replace part of the instrument cluster on his aging (yet still modern) Skoda and improve upon it in the process.

These cars have a recurring problem with the central part of the cluster that includes an LCD display. If replacement parts can even be found, they tend to cost a significant fraction of the value of the car, making them uneconomical for most. [Aravind] found that a 3.5″ color LCD that was already available fit perfectly in the space once the old screen was removed, so from there the next steps were to interface it to the car. These have a CAN bus separated from the main control CAN bus, and the port was easily accessible, so an Arduino with a RTC was obtained to handle the heavy lifting of interfacing with it.

Now, [Aravind] has a new LCD screen in the console that’s fully programmable and potentially longer-lasting than the factory LCD was. There’s also full documentation of the process on the project page as well, for anyone else with a Volkswagen-adjacent car from this era. Either way, it’s a much more economical approach to replacing the module than shelling out the enormous cost of OEM replacement parts. Of course, CAN bus hacks like these are often gateway projects to doing more involved CAN bus projects like turning an entire vehicle into a video game controller.

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A Mini USB Display For Your PC Desktop

June 20, 2021 by Jenny List 22 Comments

By now it’s likely that most Hackaday readers will be used to USB display adapters, in their most common form channeling DisplayPort over the ubiquitous serial interface. Connecting to projectors and other screens with a laptop becomes a breeze, and gone are the days of “Will my laptop work in the venue” stress for people delivering presentations. [Avra Mitra]’s STM32 tiny monitor may not ascend to these giddy heights, but it does at least live up to the promise of reproducing a desktop onto a small colour LCD hooked up through a USB port.

Not through any DisplayPort wizardry though, instead it relies on a Python script that takes successive screen grabs and streams them through USB to the microcontroller, which in tun puts them on the display. It’s claimed to achieve 6 to 7 frames per second as you can see in the video below, with an admission that there remains a huge scope for improvement.

Notwithstanding its limited utility at the moment, we can see that maybe this idea could have its uses in a very basic display after a few improvements. Meanwhile, more conventional monitors take the established route of pairing a dedicated controller board with an LCD panel.

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Recycling A Laptop Screen Into A Portable Folding Monitor

June 11, 2021 by Lewin Day 16 Comments

There’s plenty of times we’ve seen a laptop fail, break, or just become too slow for purpose despite the fact that it’s still packing some useful components. With all the single-board computers and other experiments lurking about the average hacker workshop, it’s often useful to have a spare screen on hand, and an old laptop is a great way to get one. This recycled display build from [Gregory Sanders] is a great example of how to reuse old hardware.

The build doesn’t simply package a laptop monitor in the same way as a regular desktop unit. Instead, [Gregory] designed a custom 3D printed frame with an arch design. The laptop screen is installed onto the frame using its original hinges, and [Gregory] designed in standoffs for an laptop LCD driver board to run the display as well as a generic frame where single-board computers can be installed.

The result is a portable monitor that can be folded up for easy transport, which is also self-supporting with its nice large base. It can also be used with other hardware, as it has a full complement of DVI, HDMI and VGA inputs on board. Of course, while you’re tinkering with laptop displays, you might also consider building yourself a dual-screen laptop as well.

Automated Watering Machine Has What Plants Crave: Fertilizer

May 14, 2021 by Kristina Panos 19 Comments

We’ve seen countless automated plant care systems over the years, but for some reason they almost never involve the secret sauce of gardening — fertilizer. But [xythobuz] knows what’s up. When they moved into their new flat by themselves, it was time to spread out and start growing some plants on the balcony. Before long, the garden was big enough to warrant an automated system for watering and fertilizing.

This clever DIY system is based around a 5L gravity-fed water tank with solenoid control and three [jugs] of liquid fertilizer that is added to the water via peristaltic pump. Don’t worry, the water tank has float switches, and [xythobuz] is there to switch it off manually every time so it doesn’t flood the flat.

On the UI side, an Arduino Nano clone is running the show, providing the LCD output and handling the keypad input. The machine itself is controlled with an ESP32 and a pair of four-channel relay boards that control the inlet valve, the four outlet valves, and the three peristaltic pumps that squirt out the fertilizer. The ESP also serves up a web interface that mimics the control panel and adds in the debug logs. These two boards communicate using I²C over DB-9, because that’s probably what [xythobuz] had lying around. Check out the demo video after the break, and then go check on your own plants. They miss you!

Don’t want to buy just any old peristaltic pumps? Maybe you could print your own.

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MicroLEDs: Lighting The Way To A Solid OLED Competitor

April 12, 2021 by Maya Posch 59 Comments

We’re accustomed to seeing giant LED-powered screens in sports venues and outdoor displays. What would it take to bring this same technology into your living room? Very, very tiny LEDs. MicroLEDs.

MicroLED screens have been rumored to be around the corner for almost a decade now, which means that the time is almost right for them to actually become a reality. And certainly display technology has come a long way from the early cathode-ray tube (CRT) technology that powered the television and the home computer revolution. In the late 1990s, liquid-crystal display (LCD) technology became a feasible replacement for CRTs, offering a thin, distortion-free image with pixel-perfect image reproduction. LCDs also allowed for displays to be put in many new places, in addition to finally having that wall-mounted television.

Since that time, LCD’s flaws have become a sticking point compared to CRTs. The nice features of CRTs such as very fast response time, deep blacks and zero color shift, no matter the angle, have led to a wide variety of LCD technologies to recapture some of those features. Plasma displays seemed promising for big screens for a while, but organic light-emitting diodes (OLEDs) have taken over and still-in-development technologies like SED and FED off the table.

While OLED is very good in terms of image quality, its flaws including burn-in and uneven wear of the different organic dyes responsible for the colors. MicroLEDs hope to capitalize on OLED’s weaknesses by bringing brighter screens with no burn-in using inorganic LED technology, just very, very small.

So what does it take to scale a standard semiconductor LED down to the size of a pixel, and when can one expect to buy MicroLED displays? Let’s take a look. Continue reading “MicroLEDs: Lighting The Way To A Solid OLED Competitor” →