Decades old TV gets sleep function thanks to 7400 family of chips

[Viktor] dredged up a hack he pulled off years ago. His grandfather likes to end the day in front of the TV, but he falls asleep soon after sitting down. Rather than tick away the electricity meter all night, [Viktor] built an automatic shutoff which is akin to a modern TV’s sleep feature.

At the time microcontrollers were not as easy to source as they are now. So [Viktor] used a circuit based on the 7400 family of logic chips. It uses a multivibrator to feed some binary counter chips. These are used to divide the oscillations to establish the desired timing. He tuned the system to be about 15 minutes, but that can be adjusted using a potentiometer built into the multivibrator. When time is about the run out an LED next to the TV comes on. This way if [Viktor's] grandfather is still awake he can press a button next to his chair to reset the counter. But if he’s already snoozing the counter will eventually switch off the television.

Bits and Pieces Robotic Arm

[V0R73X], who is 17  has been working on a project, to build A robotic arm. This project started out as a challenge put forward from one of his school teachers to build a robotic arm for $200.  [VoR73X] accepted, and the challenge began.

He came up with a robotic arm that can be controlled from his mobile phone and other bluetooth enabled devices. He also designed it so that he can control it from the infrared remote control of an old tv set. [VoR73X] decided to kept the design simple, to make it easy for others to build.  [VoR73X] has shared the code and a step by step process of how to build in the hopes that others would also like to take up the challenge.  Watch the video after the break for further details on his project.

via[Instructables]

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Automatic speaker control via TV

[Jon] wanted his speakers to come on and off along with his TV. The speaker heats up if left on so he didn’t want to do that. But killing the power also resets the volume level (this is an old set of PC speakers and the remote is wired, not IR) so using one of those switched power strips was out as well. He thought a bit about trying to use the power LED on the TV to build his own circuit when it dawned on him. It’s possible to monitor the USB port on the TV and use it to switch on the speakers.

The circuit above uses a couple of opto-isolators to protect both the television and the speakers. The 5V line from the USB port on the back of the TV is monitored by an XNOR gate (which helps to filter out some of the toggling at power-on). When that gate latches it activates a 555 timer which in turn fires up the speakers. Presumable this happens when power is cut as well, but we’ll let you work through the circuit logic yourself.

Use your TV remote as an HID mouse

[Vinod's] latest project lets him use a TV remote control as a mouse. It may not sound like much, but he did it with a minimum of hardware and packed in the maximum when it comes to features.

He’s using an ATmega8 to read the remote control signals and provide USB connectivity. With the V-USB stack he enumerates the device as an HID mouse. One note of warning, he used the PID/VID pair from the USBasp programmer project. If you use that programmer you’ll need to uninstall the drivers to get this to work (we think this is only necessary on a Windows box).

The cursor can be moved in eight directions using the number pad on the remote. The numeral five falls in the center of the directional buttons so [Vinod] mapped that to the left click, with the zero key serving as right click. He even included the scroll wheel by using the volume buttons. The firmware supports cursor acceleration. If you hold one direction the cursor will move slowly at first,then pick up speed. Fine adjustments can be made by single clicking the button. Check out his demonstration embedded after the break.

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Controlling a TV with a microcontroller

Here’s two builds that print text to a TV with only two pins:

Still Alive with an Arduino

After seeing all the builds that play Still Alive, [Bob] decided to take a 1972 amber monitor and recreate the cut scene at the end of PortalThe build uses the TVout library for Arduino. There were a few problems with running the Unix and Still Alive animations at the same time, so [Bob] flips a bit in the EEPROM at the end of the command line animation and restarts into GLaDOS’ report. You can check out the old school color monitor here

ATMega Video Text Generator

[Stian] didn’t think his build was good enough for Hackaday, but his friend [Mikael] thought otherwise. [Stian] wrote a library to generate an NTSC video signal in real time. It’s a text-based build with 37×17 character resolution and only requires about 3kB of RAM. As a bonus, it only takes up two pins on [Stian]‘s ATMega128.

You can check out the videos for both these builds after the break.

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You’ll throw your back out playing this analog TV synth

de-rastra

While CRT televisions fall to the wayside as more people adopt flat-panel TVs, the abundance of unused sets gives hacker/artist [Kyle Evans] an unlimited number of analog canvases on which to project his vision. He recently wrote in to share his latest creation which he dubs “de/Rastra”.

The “CRT Performance Interface” as he calls it, is an old analog television which he hacked to display signals created by moving the TV around. Fitted with an array of force sensors, accelerometers, and switches, the display is dynamically generated by the movements of whomever happens to be holding the set.

Signals are sent wirelessly from his sensor array to an Atmel 328 microcontroller with the help of a pair of XBee radios, where they are analyzed and used to generate a series of audio streams. The signals are fed into a 400W amplifier before being inserted into the CRT’s yoke, and subsequently displayed on the screen.

We’re sure [Kyle] is probably trying to express a complex metaphor about man’s futile attempts to impose his control over technology with his project, but we think it simply looks cool.

Check out [Kyle’s] work for yourself in the video below and give us your take in the comments.

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Fairly simple hack makes Samsung TVs reboot forever

[Luigi Auriemma] almost rendered his brother’s TV useless attempting to play a simple practical joke. In the process, he uncovered a bug that could potentially upset a lot of people. His idea was to connect a computer to the system via WiFi, masquerading as a remote control.  [Luigi] found that by altering the packet being sent to the TV by adding a line feed and some other characters to the name, it would begin an endless reboot loop.

He also discovered that he could easily crash the devices by setting the MAC address string too long. We’re not sure if he’s modifying the remote, or the television on this one though.

These bugs affect the Samsung TVs and Blu Ray players that utilize the same chip. The crazy part is that despite his attempts, he has been unable to contact anyone at Samsung to let them know!

[via BoingBoing]

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