[Petru] seems to have designed his weather ticker project with beginners in mind. Leveraging the inexorable forces of both the Raspberry Pi and cheap online auction house modules, it’s nearly the Hackaday equivalent of painting by numbers. But not everyone is a Picasso, and encouraging beginners to get their feet wet by painting happy little trees is a good cause.
Behind the simplicity is actually a clever architecture. An installation script makes installing the right Raspbian distro simple, and installs a few scripts that automatically update the user code from a GitHub repository. To change the code running on the machine, you can upload a new version to GitHub and press the reset button. (We would also want a way to push up code changes locally, for speed reasons.) Something like this is a great idea for a permanent Pi-based IoT device.
But as a first project, the hope is that something like this will encourage folks who find code too abstract, but who are nonetheless drawn by the allure of blinking lights, to play around with code. And unsurprisingly, this has already been entered in our Enlightened Raspberry Pi Contest which focuses on the simple-yet-impressive stuff you can do with a tiny computer and some electronics.
[Coyt] wanted a more convenient way to keep up to date with the ever-changing Bitcoin exchange rates, as well as weather and other useful information. He realized that the vacuum fluorescent display (VFD) he had purchased a couple of years ago would be perfect to display small amounts of information.
[Coyt] discovered that the VFD had a serial interface. The problem was that the VFD was looking for a 12V serial signal but the Raspberry Pi he wanted to use runs at a 3.3V. Upon closer inspection [Coyt] discovered that the VFD actually ran at lower levels as well, but it had a level converter chip installed in front of the main connector. He simply bypassed the level converter and was then able to get the RasPi speaking directly to the VFD.
The brain running this display is a Raspberry Pi. The Pi runs a Python script that pulls down all of the relevant information from the internet and displays it on the VFD. [Coyt] didn’t stop there, though. He knew that having the screen on all of the time would be somewhat of a waste, so he hooked up a PIR sensor to automatically turn on the display only when needed. The PIR sensor can detect motion in the room and will disable the display after a set period of inactivity. Most of this is powered by an LM7805 voltage regulator. While [Coyt] admits a linear regulator is not his ideal solution, it does get the job done. The metal stand acts as a nice heat sink for the regulator.
[Coyt] also wanted his project to have a certain aesthetic. He started by bending a metal plate into a stand for the electronics. He then mounted the VFD on the front of the stand and the RasPi on the back. He also mounted green LEDs between the two plates to light up the edges for a little extra pizzazz. [Coyt] believes he can use the RasPi to PWM the LEDs but this has not yet been implemented. This would allow him to pulse the light for added effect.
Since the whole thing is run by a Python script, it would be trivial to modify it to display other kinds of information. What would you do if you had a motion sensitive automatic ticker?
This visually stunning tape ticker prints out [Horatius Steam’s] emails for him. It watches his email address for a secret trigger phrase in the subject line. Sure, thermal receipt printer projects are becoming rather common, but we can’t remember seeing one that took this much time and effort to make it into a showpiece.
The two parts that make this happen are the thermal printer with cutter module and the glass dome which is just large enough to house the business end of it. The driver PCB for the printer is hidden in the base (a paper tube which is painted to took like wood), which positions the outfeed near the bottom of the dome. This had the added benefit of leaving plenty of room for [Horatius] to proudly display the paper roll. Since the receipt printer is designed to work with a Windows machine there was no custom circuitry necessary.