Tinywrench is [Tanjent’s] take on a motor controller board. It aims to replicate all of the functions that a standalone motor controller chip offers at as low a cost as possible. Early results are in. It works, and as seen can be assembled for about $8.
The top of the device offers a terminal block for connecting motors, ground, and 24V input. A pin header on the bottom has all the connections you would expect to find with a stepper motor driver board. Looking back on top there’s also a pair of ATtiny24 chips, each with its own trimpot for balancing the constant current output. Hiding on the underside of the board are two H-bridges built using high and low-side MOSFETs along with some diodes for protection, and various passive components for driving them.
As it stands, each of those H-bridges can handle around 9 amps which should be more than enough for projects with small motors. [Tanjent] mentions that one of the main advantages of working with this instead of a single motor-driver chip is that if you fry one of the MOSFETs you can replace it instead of trashing the entire board.
[Tom] recently started experimenting with Charlieplexing, and wrote in to share the 4x4x4 cube he built with an ATtiny24. Similar to this minimalist 4x4x4 LED cube we featured the other day, [Tom’s] version attempts to use the least pins possible to drive the LEDs, but in a different manner.
[Tom] didn’t want to sacrifice brightness, so he decided that the LEDs would have a 1/8 duty cycle. The problem is that the ATtiny’s I/O ports can’t support that kind of current so he needed a different means of driving the LEDs. Rather than employ any sort of shift register to control the LEDs, he opted to exclusively use transistors as he had done in previous projects.
For his Charlieplexed cube to use a total of 9 I/O pins he had to get creative with his design. He broke each level of the structure into two non-connected groups of LEDs, utilizing diagonal interconnects to get everything wired up properly.
It seems to work quite nicely as you can see in the video below. While it uses two more I/O lines than the other ATtiny cube we featured recently, we love the simple, shift register-less design.
Continue reading “ATtiny Hacks: ATtiny-controlled 4x4x4 LED Cube Has A Unique Design”
[Imsolidstate] is working to add side turn signals to a trailer. These orange clearance lights are illuminated when the vehicle’s headlights are on to increase a long trailer’s visibility. They also blink along with the turn signals on the back of the trailer. A standard 6-pin lighting harness doesn’t support this functionality so the trick is to add them without altering the towing vehicle in any way. He’s using an ATtiny24 microprocessor to interpret the logic from the vehicle and then translate the turn signal and tail light data into a signal for the additional side indicators.
We’ve all been there; hardest decision we’ve ever had to make. College and debt or freedom but no career? Start a family or live out alone? The number 2 with a small shake or side of fries?!
[Leon] sent in his random number generator, oddly enough not to just generate a number, but help us through with those life altering decisions. Using a noise diode like setup he’s able to generate random bits, which an ATtiny24 then converts and displays on a 7 segment LED. His generator also has the ability to set upper and lower limits. Seems like an awful lot of work to avoid the freedom of choice paradox, but we enjoyed the project none the less. Check out a video after the break. Continue reading “We’ll Take The Fries.”