Replacement drivers for old LED signs

led-sign-driver-replacement

The LED signs sitting idle on the left are brought to life by an Arduino replacement driver shown to the right. The big one is made by Signature Electronic and used as an advertising display like you would see in front of a business. [Bob Davis] picked it up on eBay being sold as non-working. After some power supply repair he set to the task of driving them with his own hardware.

The images he shared give us a good look at the parts used on the sign. The display area is made up of a set of eight 8×5 pixel LED modules. Each module has a key and slot in the top and bottom to help align the rows properly when building a larger array. They use TPIC6B595 shift registers (the same ones seen in yesterday’s low-res gaming hack) and 74HCT138 decoders to multiplex the pixels. Most of this info is shared in the second part of his post.

He hasn’t quite gotten the larger sign to run properly. Each row displays the same data but one pixel lower than the last. If you’ve got some insight on why this is happening we’re sure he’d like to hear about it.

[via Dangerous Prototypes]

Prototyping a low-resolution handheld gaming rig

low-res-arduino-gaming

[Jason] has been hard at work on this Arduino-based low-res gaming platform. He even had a fab house deliver circuit boards to pull everything together. It’s a little small in his hands, and the graphics are limited to the 8×8 pixels provided by the display. But it still looks like a lot of fun and the code was written to make adding new games quite painless.

The board hosts an ATmega328 which drives the bi-color LED display using a pair of TPIC6B595 shift registers. Control is provided by a collection of buttons to either side of the display. The unit is powered by three AAA batteries held in a pack soldered to the back side of the PCB.

The image above shows [Jason] giving a Space Invaders game a try. The clip after the break shows respectable action, sound from a piezo buzzer, and it even scrolls your score at the end of the game. But you’re not limited to just one title. Adding new games is as easy as implementing a class in a new header file. You can get a feel for how this is set up by viewing the source code repo.

This reminds us of the Pixel Bros low-res system.

[Read more...]

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