Drawing Images On A Character Display


[Dean Hall] doesn’t seem to know his Simpsons characters very well, but that didn’t stop him from coming up with this method for displaying a bitmap on an LCD character display with a Hitachi HD44780 chip.

[Hall] used an LCD with two 16 character rows and 8×5 pixels in each character. He displayed the image over 2×3 characters, which gave him 17×18 pixels (including the spaces between the characters) to work with. The first step after acquiring an image is to rasterize the image by hand onto graph paper. This won’t be scanned, it’s just a diagram to determine which pixels to light up.

Once the 6 characters were determined, [Hall] used this handy web-based tool to convert his graphed diagram to bitmap data. The data is loaded onto the microcontroller and the image shows up on the LCD. This is a pretty straightforward project, just be sure you properly identify your monkeys.

[via YourITronics]

How-To: Super Simple Serial Terminal

This hack shows how to make a dumb terminal out of a keyboard, LCD screen, and an 8-bit microcontroller. From time to time, a portable dumb terminal can be handy for when you have to rescue a headless server that’s acting up or if you are building a minicomputer out of a WRT, or if you just want to learn how to run a keyboard and LCD screen with a microcontroller. This super simple serial terminal will use RS-232 to control a headless linux system. Additionally, you might want to check into some of the command line interface programs that allow web browsing, AIM and IRC chatting and more directly from the terminal, but nothing beats being able to track your pizzas with this device.

The Linux system in question here will be Linux Mint. It’s a young distro based on Ubuntu that’s gaining a lot of attention lately, though the principles can be used for other Linux distros.

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Chumby Hacking By Bunnie


[bunnie] is one of the main people behind the Chumby, and even he can’t resist modding the things. He decided to outfit one with a larger LCD – using a stereo microscope to do the really fine pitch work – and a laser cutter to create a custom bezel for the finished piece. The new LCD is still a touchscreen and allows the Chumby to display 640×480 resolution over the stock 320×240. The mod requires a few parts, but the ultimate difficulty is caused by the surface mount connectors. If you’d rather have some software fun, you might want to check out [bunnie]’s Chumby wifi sniffer.