“A small project on Arduino that prints notifications coming to your phone: messages from various instant messengers, news from Twitter and everything else. Such a “telegraph apparatus” was conceived as an interesting toy without serious use, but, as it turned out, it is extremely pleasant to receive messages in the form of paper telegrams. Under the cut - a description of the operation of the device and a detailed tutorial.
Briefly about how it all works
Basically, the entire printing process boils down to three simple steps: X-axis movement (pulling the tape), Y-axis movement (pen movement), and the process of leaving a mark on the paper.
The movement along the Y axis is performed using the P. L. Chebyshev lambda mechanism , which converts rotary motion into an approximately rectilinear one.
The tape is pulled by a silicone earbud from the earbuds, rotated by a stepping motor. Ideally, the tape should be pulled through two rollers pressing against each other, but such a solution would significantly complicate the design, so the choice fell on the simplest of the working options.
In similar projects (homemade plotters, printers, etc.), the drawing process is carried out by means of a translational (or close to translational) movement of the pen up and down. Such a system is too cumbersome to be placed on the lambda mechanism, so I took a slightly different path. A solenoid is installed in the body, to which a small platform is attached, which lifts the paper tape. This solution is of little use in other projects, but it fits perfectly here. All elements are housed in a 64 × 64 mm plywood case.”