Posts with «rotary encoder» label

Man-in-the-Middle Jog Pendant: Two Parts Make Easier Dev Work

In a project, repetitive tasks that break the flow of development work are incredibly tiresome and even simple automation can make a world of difference. [Simon Merrett] ran into exactly this while testing different stepper motors in a strain-wave gear project. The system that drives the motor accepts G-Code, but he got fed up with the overhead needed just to make a stepper rotate for a bit on demand. His solution? A grbl man-in-the-middle jog pendant that consists of not much more than a rotary encoder and an Arduino Nano. The unit dutifully passes through any commands received from a host controller, but if the encoder knob is turned it sends custom G-Code allowing [Simon] to dial in a bit acceleration-controlled motor rotation on demand. A brief demo video is below, which gives an idea of how much easier it is to focus on the nuts-and-bolts end of hardware when some simple motor movement is just a knob twist away.

[Simon]’s jog pendant moves a single motor which is exactly what he needs to ease development of his 3D printed strain-wave gear using a timing belt, but it could be programmed with any G-Code at all. Speaking of DIY jog pendants for CNC machines, don’t forget this wireless one made from an Atari 2600 joystick that jogs a plasma cutter in X and Y, and zeroes it with a push of the button.

Filed under: Arduino Hacks, cnc hacks

Wheel of Resistors Form Unique Rotary Encoder

Continuing his tradition of making bits of wire and scraps of wood work wonders, [HomoFaciens] is back with a unique and clever design for an electromechanical encoder.

There are lots of ways to build an encoder, and this is one we haven’t seen before. Not intended in any way to be a practical engineered solution, [HomoFaciens]’ build log and the video below document his approach. Using a rotating disc divided into segments by three, six or eight resistors, the encoder works by adding each resistor into a voltage divider as the disc is turned. An Arduino reads the output of the voltage divider and determines the direction of rotation by comparing the sequence of voltages. More resistors mean higher resolution but decreased maximum shaft speed due to the software debouncing of the wiped contacts. [HomoFaciens] has covered ground like this before with his tutorial on optical encoders, but this is a new twist – sort of a low-resolution continuous-rotation potentiometer. It’s a simple concept, a good review of voltage dividers, and a unique way to sense shaft rotation.

Is this all really basic stuff? Yep. Is it practical in any way? Probably not, although we’ll lay odds that these encoders find their way into a future [HomoFaciens] CNC build. Is it a well-executed, neat idea? Oh yeah.

Filed under: misc hacks

Dial is a Simple and Effective Wireless Media Controller

[Patrick] was looking for an easier way to control music and movies on his computer from across the room. There is a huge amount of remote control products that could be purchased to do this, but as a hacker [Patrick] wanted to make something himself. He calls his creation, “Dial” and it’s a simple but elegant solution to the problem.

Dial looks like a small cylindrical container that sits on a flat surface. It’s actually split into a top and bottom cylinder. The bottom acts as a base and stays stationary while the top acts as a dial and a push button. The case was designed in SOLIDWORKS and printed on a 3D printer.

The Dial runs on an Arduino Pro mini with a Bluetooth module. The original prototype used Bluetooth 2.0 and required a recharge after about a day. The latest version uses the Bluetooth low energy spec and can reportedly last several weeks on a single charge. Once the LiPo battery dies, it can be recharged easily once plugged into a USB port.

The mechanical component of the dial is actually an off-the-shelf rotary encoder. The encoder included a built-in push button to make things easier. The firmware is able to detect rotation in either direction, a button press, a double press, and a press-and-hold. This gives five different possible functions.

[Patrick] wrote two pieces of software to handle interaction with the Dial. The first is a C program to deal with the Bluetooth communication. The second is actually a set of Apple scripts to actually handle interaction between the Dial and the various media programs on his computer. This allows the user to more easily write their own scripts for whatever software they want. While this may have read like a product review, the Dial is actually open source!

Filed under: Arduino Hacks, peripherals hacks

Teach kids how colors are made with the color machine

The Color Machine (La macchina dei colori, in Italian language) is a tool to teach children about the use and the operation of RGB color coding, which is used in all digital devices (TVs, smartphones, computers, etc.). It was created with Arduino Mega by an italian duo composed by Fabio Ghidini and Stefano Guerrini:

Using 3 knobs you can increase the percentages of red, green and blue separately, and the LED strip at the top of the machine lights up consistently with the color mix choosen.

The Color Machine has 4 different operating modes: “let’s create colors”, “guess the color”, “the names of the colors” and “demo”. Under the guidance of a teacher, children can play and learn at the same time to recreate colors with additive synthesis. This device is currently used in the educational workshops of Musil – Museum of Industry and Labour of Rodengo Saiano (Italy).


This is the first propotype:

Arduino Blog 09 Apr 11:05

Remote shutter module uses LCD screen for setup

Here’s a full-featured remote shutter project which [Pixel-K] just finished. It seems that he’s interested in taking time-lapse images of the cosmos. Since astrophotography happens outside at night, this presented some special design considerations. He wanted something that he could configure in the dark without zapping his night-vision too much. He also wanted it to be easily configured with a pair of gloves on.

The project enclosure is a 4x AA battery box. He removed the partitions between each cell, leaving plenty of room for the guts. Inside you’ll find a lithium battery and a micro-USB recharger board. It powers the Arduino mini pro which drives the 1.8″ LCD screen and actuates the optoisolator which is responsible for triggering the camera. On the right you can see the clear knob of the clickable rotary encoder. All of the user settings are chosen and selected using just this one knob.

He’s already tried it out on a 6-hour shoot and had no battery life problems or other issues.

Filed under: digital cameras hacks

Not all rotary encoders are created equal...

I had a hell of a time getting the (F)Light Suit remote control to work with the Modern Device LCD117 backpack and inexpensive BI EN11-HSM1AF15 rotary encoders. It turned out that I was having two issues:
  1. The LCD117 was getting its updating commands too quickly, so chose to reset instead of display, and
  2. the rotary encoders make contact so quickly when stepping up or down, my debounced code for bigger rotary encoders with more even click timing wasn't working.
Preventing the LCD117 from updating too quickly solved the first problem, and redoing the rotary encoder code from scratch solved the second problem. I'll post code later when the project is complete, but I based it on Max Wolf's very simple first example from the Arduino Playground rotary encoder page. The interrupt-based examples are too cryptic and (I think) unnecessary in a sketch that loops at a few KHz, which all of my sketches run at.