hacking lcd displays in stock

Hackaday’s own [Arsenijs Picugins] has been rather busy hacking old laptops apart and learning what can and cannot be easily reused, and presents for the 2021 Hackaday Remoticon, a heavily meme-loaded presentation with some very practical advice.

What parts inside a dead laptop are worth keeping? Aside from removable items like RAM stick and hard drives, the most obvious first target is the LCD panel. These are surprisingly easy to use, with driver boards available on the usual marketplaces, so long as you make sure to check the exact model number of your panel is supported.

It"s pretty easy to do and only requires basic tools like scissors and an X-Acto knife. You can order the polarized filter online and just use an old LCD monitor you have lying around.

they are typically much lower resolution than you may be used to on laptop computers, but the net package LCD+microcontroller is much smaller and runs off batteries for much longer than the above approaches.

Most LCD monitors have two films on the glass - a polarized one to filter out the light you are not supposed to see, and a frosted anti-glare film. The anti-glare film we don"t need, the polarized one we do - it is used for the glasses.

Print a full screenshot of the spreadsheet and taskbar onto a piece of thin, clear plastic. Convince people you can only see well with black and white, so you can make it a real high contrast print. But make sure any lines are thin. Apply this to the LCD, taking care to remove bubbles. Tehn jsut get uesd to seneig waht it looks lkie knid of srecwed up. The brain is amazing at adapting, and there is a good chance you read the last sentence naturally. Look again ^^.0

After two years of research and reverse engineering, working on the processor that controls the monitor and its firmware, Red Balloon Security researchers figured out how to hack a monitor without hacking the computer to which it is connected.

Luckily, all the digital devices in his 2012 Hyundai Genesis Coupe were connected using a fairly common standard — the “Controller Area Network bus” (or CAN bus). So Harin grabbed one of his Arduino’s — plus a cheap SPI CANBUS circuit board — and just started doing some experiments. When he first installed his Arduino circuit board into the dashboard, the LCD began showing the time of day — every ten milliseconds — and any new messages that he sent to the screen were simply being wiped out when the system re-transmitted. But Harin had already built up a strong motivation to keep moving forward, according to a recent write-up in Make: magazine, because “I hated that stupid little blue LCD. It would just sit there staring at me brightly with the words ‘AUX’…”

So he re-routed the LCD’s input. And fortunately, Harin’s other Raspberry Pi board could accommodate a WiFi dongle. By using an iPhone for connectivity, it was now able to draw down the funny Reddit quotes. And Make: also reported that his next project may be to install a router directly into his car.

Harin’s even mounted his Nexus 7 Android tablet into his car’s dashboard and is using it to play music. In the comments on his blog, he talks about one day transmitting the “now playing” information from the tablet to the LCD. Somewhere in the mix, there’s even an SQL database. “My main script retrieves the top post from Shower Thoughts and converts the characters to their hexadecimal equivalents, adds the message ID and row identifier, and stores it in an SQL database.”

There’re two more scripts just for retrieving the quote from the database and display it on the screen, which Harin says will be building blocks for more features down the road. “Eventually, I’ll be able to screen the messages intended for the LCD on the primary [CAN bus] network and add the ones I want to keep to the SQL database while removing the ones I don’t need anymore.”