[Fernando] wrote in to share his take on building a logic analyzer. He’s using the parallel port to capture data and feed it to the display software of your choice.
The method depends on a custom kernel which alters the way the parallel port works. The kernel he compiled includes a method of intercepting the signals coming in from the hardware, passing that data to the /dev/parport* as it should, but also sending a copy to /dev/parportsnif*. It also creates a log file which is in the OpenBench Logic Sniffer format for easy use with various display software.
Of course this is easiest to use with a Linux system, but can also be run as a virtual machine under Windows. We’d plan on using a virtual machine within Linux as well since this is a custom kernel and will probably only see occasional use.
Text LCD’s are handy for any occasion, a printer port on your PC is also darn handy as well. Mix together and add in a splash of linux and you get a very handy Linux device driver for a 16×2 LCD connected to the parallel port.
Electrically the LCD is wired up in a typical 4 bit mode, this allows the parallel port to use its 8 bit data register to write data, but also control the Register Select and Enable pins. Next is to make a module for linux to use, it seems like pretty standard fair for this type of screen.
Make the driver, insert the module so it can be loaded, and add a node so you know where to find it later, and your only an “echo Hello > /dev/my_lcd” away from finding all sorts of creative uses for your new external display.
[Neil] is driving this Siemens A60 LCD using a parallel port on his Linux box. He likes this module because it has an integrated LED back-light, controller IC, and the pads are large enough for a human to solder. He notes that the screen runs on 2.9V, which matches the forward voltage of the LEDs used as back-lights. This means it is possible to use one f the LEDs as a shunt to drop incoming voltage down to a safe level for the controller. In fact, that’s what he did. The data lines are connected to the parallel port along with some current limiting resistors. The LEDs are connected with resistor calculated for maximum brightness, with the output from the LED used as the source voltage for the LCD controller chip.Whether you want to use one of these screens with a PC or something else, the code that [Neil] worked out should provide the information necessary to do so.
The Nokia cellphone LCD post inspired [Neil] to send in a tip about this project. If you’ve got well documented hacks that you’re just sitting on why not let us know about them?
When we saw [merkz] use of an Arduino to produce lucid dreaming we were quite shocked. Unlike typical setups that just flash a light through sleep, his system monitors eye movement through electrodes and is able to send the data to a computer for graphing and analyzing. The only problem being we couldn’t find a circuit diagram or code.
Not ones to be shot down so quickly, a Google revealed this thread on making ‘Dream Goggles’, which was really a Brain-Wave Machine based on the parallel port. Some modifications of an ECG collector’s electrodes using sound cards, and you could have your own lucid dreaming.
You can pick up a Wii Motion Plus module for under $20 and that’s not bad for an I2C gyroscope. This hack taps into the device through a PC parallel port. The connection calls for some level conversion to step down to the 3.3v needed by the module. The communication protocol borrows from the Wii on Arduino code examples that we saw last year. You can see the Wii Motion Plus controlling a virtual cube in the video after the break.
Continue reading “Wii motion plus direct PC interface”
[lucassiglo21] let us know about his finished 3 axis CNC (Translation via Google). While home CNCs are nothing new, we really liked this masterpiece. The CNC is entirely custom, from the electronic control boards (connected to a PC via parallel port) to the physical mill (with an end result of 30x30x15cm workable area). Our favorite part is the use of screw/band clamp zip ties to hold the Dremel – a true showing of hacker geekyness. For those who haven’t seen a CNC drill a circle before (and honestly, who hasn’t?), check a video after the break.
Continue reading “CNC brought to you by zip ties”
Sometimes, pets need to be trained to stay away from certain things. Over at sump.org, his cats needed to be kept out of his room. He used their natural fear of water by creating the waterwall, a motion-sensing device that sprays water. The project is incredibly simple and uses very few components. It is based around an IR intrusion detector and a windshield washer pump. Although that worked well enough, he also hooked it up to his computer via the parallel port so that he could take pictures as the cats (or people) are sprayed. Although the project is old, it shows how few components are really needed to achieve this kind of behavior.
Related: Motion detecting cat toy