If you want to sell a toy for the toddler crowd, it ought to be pretty close to indestructible. A lot of toys out there are just plain nonsense game-wise and therefore waste their beefy potential. [2dom]’s wife was close to throwing out such a toy—a Little Tikes Goofy Ball. The thing literally does nothing but let you push its big buttons in. After some time passes, it pops them back out again and giggles. Game over. [2dom] rescued it from the trash and turned it into a toy that plays math games.
[2dom] removed the existing board and replaced it with an Arduino Pro Mini and a Darlington array that drives the motor that pops the buttons back out, the speaker, and a Nokia 5110 screen. Upon startup, the user chooses between addition, subtraction, and multiplication questions using the appropriate button. Questions appear in the middle of the screen and multiple choice answers in the corners.
Choose the right answer and the ball cheers and shows one of a few faces. Choose the wrong answer and it makes a buzzing sound and shows an X. There is an adaptive level system for the questions that [2dom] doesn’t show in the demonstration video after the break. For every five correct answers, you level up. His 3- and 5-year-olds love it. For more advanced teachable moments, there’s this toy-turned-enigma-machine.
Continue reading “Mindless Toddler Toy Becomes Teaching Tool”
Having the “can you believe somebody threw this away?” mentality has gotten us into some trouble through the years, but look what [Joshua] found at the scrap yard! It’s a door from a power conversion station and it contains fourteen indicator lights and a lot of other doodads. But since this is just the door, he needed a way to monitor the controls and drive the indicators. At the heart of the hack he used to get this up and running is a PIC 18F2550. It has no trouble driving the indicators thanks to a pair of ULN2803 darlington arrays which switch the higher 24 volt levels.
His writeup doesn’t mention the method used, but the panel also has a couple of meters at the top. In the video after the break you can clearly see that he’s got them both working. We’d bet there’s a plan for each of the buttons as well, since this will be prominently featured in their alien-invasion themed Halloween display this year.
Continue reading “Great junk-yard find leads to a reclaimed control panel project”
Don’t reach for a sticky note when you need to leave a message for your office mates, write it down on a 12 foot LED marquee. [Kitesurfer1404] built this for his home office, but we’re sure he’ll find fun stuff to use it for. The display has 512 LEDs driven by plain old 595 shift registers for the high-side columns, with an ULN2803A Darlington Array to pull the eight rows to ground. The whole thing is controlled by an ATmega8 via a serial connection. Our compliments to the builder for accurately drilling a grid of 64×8 holes in each hardboard panel of the display. The buses for each row and column also look nice and clean. For the final look a 79% light transmittance frosted acrylic panel was added to diffuse the light.
We used the same method to build our LED pumpkin. Transistors ran the low side, and if we had needed more columns, shift registers are a popular go-to for I/O expansion. Check out that project to learn more about display multiplexing.