Adding Smarts To Dumb Brushed Motors

June 25, 2018 by Brian Benchoff 12 Comments

A big part of the Hackaday Prize this year is robotics modules, and already we’ve seen a lot of projects adding intelligence to motors. Whether that’s current sensing, RPM feedback, PID control, or adding an encoder, motors are getting smart. Usually, though, we’re talking about fancy brushless motors or steppers. The humble DC brushed motor is again left out in the cold.

This project is aiming to fix that. It’s a smart motor driver for dumb DC brushed motors. You know, the motors you can buy for pennies. The motors that are the cheapest way to add movement to any project. Those motors.

The Smart Motor Driver for Robotics allows a DC brushed motor to be controlled by a host microcontroller over I2C, and sends back the speed and direction of the motor. PID is implemented, and the motor can maintain its own speed, independently of a lot of difficult control on the host system.

The guts of this motor controller are made of a PIC 12F microcontroller, a H-bridge motor driver, a Hall-effect sensor, and a neat magnetic encoder disc. Ultimately, this project will simply bolt onto the back of a cheap brushed motor and give it the same capabilities as a fancy servo or stepper. It’s never going to have the same torque or power handling as a beefy NEMA 17 stepper, but sometimes you don’t need that, and a simple brushed motor will do. A great project, and an excellent entry for the Hackaday Prize.

Modular Robotics That Can Make Themselves Into Anything

June 24, 2018 by Brian Benchoff 9 Comments

The greatest challenge of robotics is autonomy. Usually, this means cars that can drive themselves, a robotic vacuum that won’t drive down the stairs, or a rover on Mars that can drive on Mars. This project is nothing like that. Instead of building a robot with a single shape, this robot is made out of several modules that can self-assemble into different structures. It’s an organized fleet of robots, all helping each other, like an ant colony, or our future as Gray Goo.

If the idea of self-assembling modular robots sounds familiar, you’re right. The Dtto won the Grand Prize in the 2016 Hackaday Prize, and it’s a beast of a project. It’s an ouroboros of a robot that can assemble itself into a snake, a wheel, or an arm. It’s weird, but if you want a robot that can do anything, this is the kind of modularity that you need. One step closer to Gray Goo, at least.

Like Dtto, the noMad can transform itself into bridges, arms, snakes, and wheels by assembling each individual piece into one component of a massive structure. It’s something we rarely see, and it’s a difficult computational and engineering problem. Still, the progress the team behind noMad has been making is remarkable, and we can’t wait to see the finished project.

ROPS Will Be The Board X86 Robot Builders Are Waiting For

June 23, 2018 by Jenny List 29 Comments

If your robot has outgrown a Raspberry Pi and only the raw computing power of an x86 motherboard will suffice, you are likely to encounter a problem with its interfaces. The days of ISA cards are long gone, and a modern PC is not designed to easily talk to noisy robot hardware. Accessible ports such as USB can have interfaces connected to them, but suffer from significant latency in the process.

A solution comes from ROPS, or Robot on a PCI-e Stick, a card that puts an FPGA on a blazing-fast PCI-e card that provides useful real-world interfaces such as CAN and RS485 and a pile of I/O lines as well as an IMU, barometer, and GPS. If you think you may have seen it before then you’d be right, it was one of the first-round winners of the Open Hardware Design Challenge. They’re very much still at the stage of having an FPGA dev board and working out the software so there aren’t any ROPS boards to look at yet, but this is a project that’s going somewhere, and definitely one to watch.

Your Own Sinclair Scientific Calculator

June 22, 2018 by Al Williams 19 Comments

We’ve talked about the Sinclair scientific calculator before many times, and for some of us it was our first scientific calculator. If you can’t find yours or you never had one, now you can build your own using — what else — an Arduino thanks to [Arduino Enigma]. There’s a video, below and the project’s homepage on Hackaday.io describes it all perfectly:

The original chip inside the Sinclair Scientific Calculator was reverse engineered by Ken Shirriff, its 320 instruction program extracted and an online emulator written. This project ports that emulator, written in Javascript, to the Arduino Nano and interfaces it to a custom PCB. The result is an object that behaves like the original calculator, with its idiosyncrasies and problems. Calculating PI as arctan(1)*4 yields a value of 3.1440.

Special care was taken in the design of the emulator to match the execution speed of the
original calculator, which varies from acceptable to atrocious for trigonometric functions involving small angles.

Continue reading “Your Own Sinclair Scientific Calculator” →

Evolving The 3D Printed Linear Actuator

June 22, 2018 by Roger Cheng 10 Comments

Our open source community invites anyone with an idea to build upon the works of those who came before. Many of us have encountered a need to control linear motion and adapted an inexpensive hobby servo for the task. [Michael Graham] evaluated existing designs and believed he has ideas to advance the state of the art. Our Hackaday Prize judges agreed, placing his 3D Printed Servo Linear Actuator as one of twenty winners of our Robotics Module Challenge.

[Michael]’s actuator follows in the footstep of other designs based on a rack-and-pinion gear such as this one featured on these pages, but he approached the design problem from the perspective of a mechanical engineer. The design incorporated several compliant features to be tolerant of variances between 3D printers (and slicer, and filament, etc.) Improving the odds of a successful print and therefore successful projects. Beginners learning to design for 3D printing (and even some veterans) would find his design tips document well worth the few minutes of reading time.

Another useful feature of his actuator design is the 20mm x 20mm screw mounting system. Visible on either end of the output slider, it allows mixing and matching from a set of accessories to be bolted on this actuator. He is already off and running down this path and is facing the challenge of having too many things to share while keeping them all organized and usable by everyone.

The flexible construction system allows him to realize different ideas within the modular system. He brought one item (a variant of his Mug-O-Matic) to the Hackaday + Tindie Meetup at Bay Area Maker Faire, and we’re sure there will be more. And given the thoughtful design and extensive documentation of his project, we expect to see his linear servos adopted by others and appear in other contexts as well.

This isn’t the only linear actuator we’ve come across. It isn’t even the only winning linear actuator of our Robotics Module Challenge, but the other one is focused on meeting different constraints like compactness. They are different tools for different needs – and all worthy additions to our toolbox of mechanical solutions.

CNC Mod Pack Hopes To Make Something Useful From A Cheap Machine Tool

June 21, 2018 by Jenny List 13 Comments

It is probable that many of us have noticed a variety of very cheap CNC mills in the pages of Chinese tech websites and been sorely tempted. On paper or as pixels on your screen they look great, but certainly with the more inexpensive models there soon emerges a gap between the promise and the reality.

[Brandon Piner] hopes to address this problem, with his CNC Mod Pack, a series of upgrades to a cheap mill designed to make it into a much more useful tool. In particular he’s created a revised 3D-printed tool holder and a set of end stop switches. The tool holder boasts swappable mounts on a dovetail fitting with versions for both a laser diode and a rotary tool, allowing much better tool positioning. Meanwhile the end stops are a necessary addition that protects both tool and machine from mishaps.

The same arguments play out in the world of small CNC mills as do in that of inexpensive 3D printers, namely that the economy of buying the super-cheap machine that is nominally the same as the expensive one starts to take a knock when you consider the level of work and expense needed to make your purchase usable. But with projects like this one the barrier to achieving a quality result from an unpromising start is lowered, and the enticing prospect is raised of a decent CNC machine for not a lot.

Hexabitz, Modular Electronics Made Easier

June 20, 2018 by Jenny List 14 Comments

Over the years there have been a variety of modular electronic systems allowing the creation of complex circuits by the interconnection of modules containing individual functions. Hexabitz, a selection of interlocking polygonal small PCBs, is just such a system. What can it bring to the table that others haven’t done already?

The problem facing designers of modular electronics is this: all devices have different requirements and interfaces. To allow connection between modules that preserves all these connections requires an ever-increasing complexity in the inter-module connectors, or the application of a little intelligence to the problem. The Hexabitz designers have opted for the latter angle, equipping each module with an STM32 microcontroller that allows it to identify both itself and its function, and to establish a mesh network with other modules in the same connected project. This also gives the system the ability to farm off computing tasks to individual modules rather than relying solely upon a single microcontroller or single-board computer.

An extremely comprehensive array of modules can be had for the system, which lends it some interesting possibilities, however, it suffers from the inherent problem of modular electronic systems, that it is less easy to incorporate non-standard functions. If they can crack a prototyping module coupled with an easy way to tell its microcontroller to identify whatever function is upon it, they might have a winner.