Chart recorders are vintage devices that were used to plot analog values on paper. They’re similar to old seismometers which plot seismic waves from earthquakes. The device has a heated pen which moves across a piece of thermally sensitive paper. This paper is fed through the machine at a specified rate, which gives two dimensions of plotting.
[Marv] ended up getting a couple of discontinued chart recorders and figured out the interface. Five parallel signals control the feed rate of the paper, and an analog voltage controls the pen location. The next logical step was to hook up an Arduino to control the plotter.
However, once the device could plot analog values, [Marv] quickly looked for a new challenge. He wanted to write characters and bitmaps using the device, but this would require non-continuous lines. By adding a solenoid to lift the pen, he built a chart recorder printer.
After the break, check out a video of the chart recorder doing something it was never intended to do. If you happen to have one of these chart recorders, [Marv] included all of the code in his writeup to help you build your own.
Continue reading “Printing Text with a Chart Recorder”
Well, if you hadn’t noticed the news there has been a little bit of a shakeup on the east coast. I just arrived home after being evacuated due to a 30 second rumble the likes of which has not been felt on the east coast in something like 114 years. In lieu of the not so devastating but earth shaking event we thought we’d put together a few earthquake related links for you.
Earthquake-proof Wine Rack
First off instructables user [jofish] has a quick remedy if earthquakes are constantly destroying all the wine on your wine rack. He researched some existing commercial products and simply copied them by stapling cheap O rings to the front of the rack. We assume the back of the wine rack is secured to the wall as well.
Next up is a vertical seismometer from [Mike] over at mikesense.com. This was in response to a slightly more threatening 7.2 earthquake he experienced in Baja California last year. A vertical seismometer measures the movement of a weight either electronically or mechanically, and then damps the motion of the oscillation by a magnet or some other means. This particular design is known as the AS-1 developed by [Jeff Batten]. Matt’s page has links to everything you’d need to know including build videos.
Predict Seismic Activity with Hard Drives
If you are looking for some non-conventional ways of tracking seismic activity we have a pair of articles that detail earthquake tracking using your disk drive’s accelerometer. [Michael Stadler] realized the potential for all these sensors and released a program that creates a peer-to-peer network compiling data from the sensors. We are not too comfortable with the prospect of somebody tracking every time we drop or kick (or drop-kick) our laptops but 2500 users in Asia downloaded the software in ’06. The second article details an effort lead by IBM to monitor the fixed hard drives in server racks which generally remain far more stationary.
Simple DIY Earthquake Simulator
Finally for those of you who want to cause (miniature) earthquakes, we dug up this MTU project using plywood, an electric drill, rubber bands and some bearings to fabricate a DIY shake table (PDF warning). We are sure there are tons of improvements that can be made but this is a pretty fun project if you have a bunch of CNC parts lying around (we wish we did).