Adafruit launches educational show aimed at kids

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Adafruit Industries just posted the first episode in a new educational series aimed at teaching kids about electronics. The episode is entitled “A is for Ampere” and teaches the basic theory behind electrical current. The subject seems like a common one for A-to-Z themed electrical tutorials. [Jeri Ellsworth] did a similar episode but hers is aimed more at the electronics hobby crowd.

[Limor] and gang (that’s [Collin Cunningham] dressed up as [Andre-Marie Ampere]) seem to be all-in on this project. The episode features ADABOT, the blue puppet which takes on the role of the student in this episode. After demonstrating a mains circuit breaker tripping the episode goes on to discuss electron flow and how current is measured.

We’re all about this type of educational opportunity. The age group at which this series is targeted have never known a day without touchscreens, they should know at least something about how those devices actually work.

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How-to: turn on a light bulb

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All too often, the commentors here on Hackaday display some parsimony in their engineering prowess. If someone uses a Raspberry Pi to blink a few LEDs, someone will invariably chime in that an ARM microcontroller would do just as well. Switching a relay on and off belies the capabilities of a 32-bit Cortex microcontroller when a simpler 8-bit build would certainly suffice. Of course this can always be reduced to a 555 circuit and further still to conditioned pigeons tapping a key in response to either food or opiates. I’d like to take this opportunity to present a tutorial. Not just any tutorial, but the actual foundation of everything we love here at Hackaday: blinky, glowey things.

You can check out the rest of this tutorial after the break.

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Learn shift registers without involving a microcontroller

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This is a truly hands-on approach to learning. [Kevin Darrah] ditched the microcontroller and is using push buttons to learn about 595 shift registers. The test rig uses two of the serial-in, parallel-out chips. These are cascading which means that as data from the first chip overflows it feeds the input of the second. The parts are commonly used to drive LEDs, or reduce the number of pins needed to drive peripherals like this character LCD.

The five push-buttons give you a chance to intuitively learn how the chip logic works. The blank button is also commonly called Output Enable (OE). Driving it high shuts off the outputs of the chips but doesn’t clear the data. That task is performed by the clear button which is driven low to set all of the shift register memory to zero. The other three buttons set the logic level, shift it into the chip using the clock signal, and push the stored values to the outputs using the latch.

To get a visual approximation of what’s happening inside of these chips you should check out the shift register tutorial linked to in this post.

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Learn a little assembly language for the 6502 processor

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Evern wanted to write your own Atari 2600 games? This won’t get you quite that far, but it will teach you the very basics. It’s an assembly tutorial for the 6502 processor. The nice thing is that you need nothing more than your browser to participate thanks to the embedded JavaScript emulator which acts as assembler, machine, and debugger in one.

The 6502 was in a lot of early equipment. In addition to the previously mentioned Atari they can be found in the Commodore 64, Apple II, and the original NES. You can even find folks building their own computers around the chip these days (most notable to us is the Veronica project). The guide starts off slowly, providing a working program and challenging the reader to play with to code in order to alter the outcomes. It moves on to an overview of registers and instructions, operators and branching, and culminates in the creation of a simple game.

[Thanks Mathilda]

RPi Video with Pygame

Adafruit has a new tutorial on creating video with an RPi and pygame. The goal is to create custom user interfaces on low cost hardware, powered by the easy to use pygame library. The tutorial walks through getting your RPi set up to run pygame, creating a basic pygame script that controls the framebuffer, and drawing an oscilloscope display on the screen.

This tutorial uses Adafruit’s WebIDE as a development environment. This is an excellent solution for working on video display, since you can develop the code on a networked computer and view the shell while running your graphical application. This is very useful for debugging, since you can just print information to your WebIDE console.

There’s a lot of potential for this setup. It would be ideal for creating any kiosk application. Maybe an announcement display, interactive kiosk, or even a programmable logic controller type user interface? What else could you build with a RPi attached to a LCD touchscreen?

Check out a video of Adafruit’s display in action after the break.

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The inner workings of servo motors

Servos seem to be the go-to option when adding motors to hobby projects. They’re easy to hack for continuous rotation for use in a robot, but with the control board intact they are fairly accurate for position-based applications. But do you know how the hardware actually works? [Rue Mohr] recently published an article that looks at the inner world of the servo motor.

As you know, these motors use a voltage, ground, and signal connection for control. The position of the horn (the wheel seen on the servos above) is dependent on that control signal. The duty cycle of a 20 ms pulse decides this. Inside the housing is a control board capable of measuring this signal. It’s got a chip that monitors the incoming PWM pulses, but that’s only half of the equation. That controller also needs feedback from the horn to know if its position is correct or needs to be changed. Integrated with the gear box that connects the motor to the horn is a potentiometer. It’s resistance changes as the horn turns. Knowing this, it is possible to fine tune a servo by altering that resistance measurement.

Cheap spark detector for alpha particles

[JAC_101] wrote in to let us know that the Truely Mad Scientist’s LVL1 Splinter Group just built a simple Alpha Particle detector.  The detector is a high voltage DC spark gap that is triggered by ionizing radiation. Making one of these detectors involves gutting a cold cathode power supply for some high voltage AC, then bumping that source up to crazy high voltage DC with a Cockcroft-Walton generator.  Once the spark gap distance is carefully adjusted it will light up brilliantly with the introduction of a radioactive source, we are told. There are no videos, or even pictures of the thing running, but we found this one that is pretty darn cool. Maybe all that spark-gap related RF killed their camera or something, their page at least promises videos soon.

In the mean time check out Truely Mad Scientist’s LVL1 Splinter Group’s ionizing cloud chamber for more radioactive fun.