A little MDF, a little plywood, some bits of threaded rod – put it all together and you’ve got this low-cost desktop CNC build using very few parts you’d need to go farther afield than the local home center to procure.

We’ve seen lots of e-waste and dumpster diving CNC builds here before; what’s appealing here is not only the low price tag of the build but also its approachability. As the short videos below show, [Thimo Voorwinden] does an admirable job of using the tools and materials he has on hand. We also appreciate the modularity of the build – the X- and Y-axis carriages are nearly identical and could be interchanged to alter the dimensions of the work area, or even replaced with a larger carriage if needed. The Z-axis is a little different from the usual low-end CNC build in that it doesn’t use a Dremel or other small rotary tool but rather mounts the handpiece of a flexible shaft rotary tool. Keeping the motor off the machine allows for more torque, less vibration, and reduced dead load.

The end result is a desktop CNC for about €200 with a work area large enough to fabricate small wooden and plastic parts, or to mill foam blocks for use as casting molds. It looks like [Thimo] has more in store for his little CNC machine, and we’re looking forward to seeing what improvements he can come up with.

[ via r/CNC]

Les Boites Mécaniques are a set of four automated boxes that produce music out of wood and metal. These experimental instruments enable anyone to explore the magic of making sound by pressing buttons on a remote, which activate each respective device to vibrate, knock, and rub materials.

The boxes were developed by Kogumi‘s Anatole Buttin and Yan Godat for educational electronic music workshops, and can be played either solo or in unison. There’s even a mode that allows users to control it all via MIDI notes on a computer.

In terms of hardware, each box is equipped with an Arduino Uno, a TLC59711 LED driver, step motors with AccelStepper library and a 3D-printed microstep driver.

You can watch how it all comes together to create a unique sound below!

[Tim] was tired of compromising his portrait-oriented digital photos by shoehorning them into landscape-only frames. Unable to find a commercial solution, he built his own rotating digital photo frame from a 27″ LCD TV.

It uses a Raspi 3 to find [Tim]’s pictures on a giant SD card. He originally wanted to have the Pi pull pictures from Google Photos and display them randomly, but the API doesn’t work in that direction. Instead, a Python script looks at the pictures on the SD card and determines whether each is landscape or portrait-oriented. If a picture was taken in portrait-mode, the display will rotate 90 degrees. Rotation is handled with an Arduino, a stepper motor, and some 3D-printed herringbone gears. The first version was a bit noisy, so [Tim] re-printed the motor mount and the pinion gear out of flexible filament.

[Tim] designed the mount and frame himself and laser-cut the pieces out of birch plywood. We like that he accounted for the front-heaviness and that he covered the high voltage circuitry with acrylic to mitigate the risk of shock. All the code and design files are available on his project page. Make the jump to see a brief demonstration followed by a walk-through and stay for the six-minute slide show.

[gocivici] threatened us with a tutorial on positional astronomy when we started reading his tutorial on a Arduino Powered Star Pointer and he delivered. We’d pick him to help us take the One Ring to Mordor; we’d never get lost and his threat-delivery-rate makes him less likely to pull a Boromir.

As we mentioned he starts off with a really succinct and well written tutorial on celestial coordinates that antiquity would have killed to have. If we were writing a bit of code to do our own positional astronomy system, this is the tab we’d have open. Incidentally, that’s exactly what he encourages those who have followed the tutorial to do.

The star pointer itself is a high powered green laser pointer (battery powered), 3D printed parts, and an amalgam of fourteen dollars of Chinese tech cruft. The project uses two Arduino clones to process serial commands and manage two 28byj-48 stepper motors. The 2nd Arduino clone was purely to supplement the digital pins of the first; we paused a bit at that, but then we realized that import arduinos have gotten so cheap they probably are more affordable than an I2C breakout board or stepper driver these days. The body was designed with a mixture of Tinkercad and something we’d not heard of, OpenJsCAD.

Once it’s all assembled and tested the only thing left to do is go outside with your contraption. After making sure that you’ve followed all the local regulations for not pointing lasers at airplanes, point the laser at the north star. After that you can plug in any star coordinate and the laser will swing towards it and track its location in the sky. Pretty cool.

Do any of you stay awake at night agonizing over how the keytar could get even cooler? The 80s are over, so we know none of us do. Yet here we are, [James Cochrane] has gone out and turned a HP ScanJet Keytar for no apparent reason other than he thought it’d be cool. Don’t bring the 80’s back [James], the world is still recovering from the last time.

Kidding aside (except for the part of not bringing the 80s back), the keytar build is simple, but pretty cool. [James] took an Arduino, a MIDI interface, and a stepper motor driver and integrated it into some of the scanner’s original features. The travel that used to run the optics back and forth now produce the sound; the case of the scanner provides the resonance. He uses a sensor to detect when he’s at the end of the scanner’s travel and it instantly reverses to avoid collision.

A off-the-shelf MIDI keyboard acts as the input for the instrument. As you can hear in the video after the break; it’s not the worst sounding instrument in this age of digital music. As a bonus, he has an additional tutorial on making any stepper motor a MIDI device at the end of the video.

If you don’t have an HP ScanJet lying around, but you are up to your ears in surplus Commodore 64s, we’ve got another build you should check out.

Woodworking and electronics, automatons and camera sliders. Ben Brandt's YouTube channel offers lots of cool projects.

Read more on MAKE

The post Weekend Watch: B2Builds Dives into Electronics and Woodworking appeared first on Make: DIY Projects and Ideas for Makers.

Is it something in the water, or have there been a lot of really cool servo projects lately? Mechaduino is a board that sits on a regular stepper motor and turns it into a servo with a closed loop control of 0.1degree.

Whenever we post something about using cheap brushless motors for precision control, someone comments that a stepper is just a brushless motor with a lot of poles, why not just control it like one. That’s exactly what the Mechaduino does. They also hint at doing something very clever with a magnetic encoder on the board which allows them, after a calibration routine, to get the accuracy they’ve promised.

T
he Arduino-sounding bit of the name comes from their full compatibility with the Arduino development environment. The brains of the board is the compatible,  SAMD21 ARM M0+  chip. They wanted the board to be as accessible as possible. On top of this, it also allows the user to use any control algorithm they want for the board. Most industrial controllers are limited to PID control, for returning to the last sent position. Opening up the control allows for interesting applications, such as motors that behave like mass spring damper systems, or electronically gearing the input of one stepper to the output of another.

The board supports lots of standard communication protocols, but the acceptance of regular stepper inputs make it extra interesting. It can become a drop-in replacement for the motors on a normal CNC or 3D printer, which have full closed loop control as shown in the video after the break.

They intend to keep working on the project until it gets to a level where they could kickstart it. However, rather than vaguely promise an open source release sometime after the launch like some have done, interested readers can skim all the design files off their GitHub and get to playing with it today. Firmware and Hardware.

Lots of people get a pet and then hack solutions that help them care for their new friend, like an automatic door to provide access to the great outdoors. Then again, some people build the pet door first and then build the pets to test it.

It’s actually not quite as weird as it sounds. [Amir Avni] and his wife attended a recent GeekCon and entered the GeekCon Pets event. GeekCon is a cooperative rather than competitive hackathon that encourages useless builds as a means to foster community and to just have some fun. [Amir] and his wife wanted to build a full-featured automatic pet door, and succeeded – with NFC and an ESP8266, the stepper-powered door worked exactly as planned. But without any actual animal companions to test the system, they had to hack up a few volunteers. They came up with a 3D-printed dog and cat perched atop wireless cars, and with NFC tags dangling from their collars, the door was able to differentiate between the wandering ersatz animals. The video below the break shows the adorable plastic pals in action.

It’s clear from all the pet doors and automatic waterers and feeders we’ve seen that hackers love their pets, but we’re pretty sure this is the first time the pet itself was replaced by a robot. That’s fine for the test environment, but we’d recommend the real thing for production.

[via r/arduino]

Learn how to use inexpensive L298N motor control modules to drive DC and stepper motors with Arduino. This is chapter fifty-nine of our huge Arduino tutorial series.

You don’t have to spend a lot of money to control motors with an Arduino or compatible board. After some hunting around we found a neat motor control module based on the L298N H-bridge IC that can allows you to control the speed and direction of two DC motors, or control one bipolar stepper motor with ease.

The L298N H-bridge module can be used with motors that have a voltage of between 5 and 35V DC. With the module used in this tutorial, there is also an onboard 5V regulator, so if your supply voltage is up to 12V you can also source 5V from the board.

So let’s get started!

First we’ll run through the connections, then explain how to control DC motors then a stepper motor. At this point, review the connections on the L298N H-bridge module.

Consider the following image – match the numbers against the list below the image:

1. DC motor 1 “+” or stepper motor A+
2. DC motor 1 “-” or stepper motor A-
3. 12V jumper – remove this if using a supply voltage greater than 12V DC. This enables power to the onboard 5V regulator
4. Connect your motor supply voltage here, maximum of 35V DC. Remove 12V jumper if >12V DC
5. GND
6. 5V output if 12V jumper in place, ideal for powering your Arduino (etc)
7. DC motor 1 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
8. IN1
9. IN2
10. IN3
11. IN4
12. DC motor 2 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
13. DC motor 2 “+” or stepper motor B+
14. DC motor 2 “-” or stepper motor B-

Controlling DC Motors

To control one or two DC motors is quite easy with the L298N H-bridge module. First connect each motor to the A and B connections on the L298N module. If you’re using two motors for a robot (etc) ensure that the polarity of the motors is the same on both inputs. Otherwise you may need to swap them over when you set both motors to forward and one goes backwards!

Next, connect your power supply – the positive to pin 4 on the module and negative/GND to pin 5. If you supply is up to 12V you can leave in the 12V jumper (point 3 in the image above) and 5V will be available from pin 6 on the module. This can be fed to your Arduino’s 5V pin to power it from the motors’ power supply. Don’t forget to connect Arduino GND to pin 5 on the module as well to complete the circuit.

Now you will need six digital output pins on your Arduino, two of which need to be PWM (pulse-width modulation) pins. PWM pins are denoted by the tilde (“~”) next to the pin number, for example:

Finally, connect the Arduino digital output pins to the driver module. In our example we have two DC motors, so digital pins D9, D8, D7 and D6 will be connected to pins IN1, IN2, IN3 and IN4 respectively. Then connect D10 to module pin 7 (remove the jumper first) and D5 to module pin 12 (again, remove the jumper).

The motor direction is controlled by sending a HIGH or LOW signal to the drive for each motor (or channel). For example for motor one, a HIGH to IN1 and a LOW to IN2 will cause it to turn in one direction, and  a LOW and HIGH will cause it to turn in the other direction.

However the motors will not turn until a HIGH is set to the enable pin (7 for motor one, 12 for motor two). And they can be turned off with a LOW to the same pin(s). However if you need to control the speed of the motors, the PWM signal from the digital pin connected to the enable pin can take care of it.

This is what we’ve done with the DC motor demonstration sketch. Two DC motors and an Arduino Uno are connected as described above, along with an external power supply. Then enter and upload the following sketch:

// connect motor controller pins to Arduino digital pins
// motor one
int enA = 10;
int in1 = 9;
int in2 = 8;
// motor two
int enB = 5;
int in3 = 7;
int in4 = 6;
void setup()
{
  // set all the motor control pins to outputs
  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
}
void demoOne()
{
  // this function will run the motors in both directions at a fixed speed
  // turn on motor A
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);
  // set speed to 200 out of possible range 0~255
  analogWrite(enA, 200);
  // turn on motor B
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);
  // set speed to 200 out of possible range 0~255
  analogWrite(enB, 200);
  delay(2000);
  // now change motor directions
  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH); 
  delay(2000);
  // now turn off motors
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
}
void demoTwo()
{
  // this function will run the motors across the range of possible speeds
  // note that maximum speed is determined by the motor itself and the operating voltage
  // the PWM values sent by analogWrite() are fractions of the maximum speed possible 
  // by your hardware
  // turn on motors
  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH); 
  // accelerate from zero to maximum speed
  for (int i = 0; i < 256; i++)
  {
    analogWrite(enA, i);
    analogWrite(enB, i);
    delay(20);
  } 
  // decelerate from maximum speed to zero
  for (int i = 255; i >= 0; --i)
  {
    analogWrite(enA, i);
    analogWrite(enB, i);
    delay(20);
  } 
  // now turn off motors
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);  
}
void loop()
{
  demoOne();
  delay(1000);
  demoTwo();
  delay(1000);
}

So what’s happening in that sketch? In the function demoOne() we turn the motors on and run them at a PWM value of 200. This is not a speed value, instead power is applied for 200/255 of an amount of time at once.

Then after a moment the motors operate in the reverse direction (see how we changed the HIGHs and LOWs in thedigitalWrite() functions?).

To get an idea of the range of speed possible of your hardware, we run through the entire PWM range in the function demoTwo() which turns the motors on and them runs through PWM values zero to 255 and back to zero with the two for loops.

Finally this is demonstrated in the following video – using our well-worn tank chassis with two DC motors:

Controlling a Stepper Motor

Stepper motors may appear to be complex, but nothing could be further than the truth. In this example we control a typical NEMA-17 stepper motor that has four wires:

It has 200 steps per revolution, and can operate at at 60 RPM. If you don’t already have the step and speed value for your motor, find out now and you will need it for the sketch.

The key to successful stepper motor control is identifying the wires – that is which one is which. You will need to determine the A+, A-, B+ and B- wires. With our example motor these are red, green, yellow and blue. Now let’s get the wiring done.

Connect the A+, A-, B+ and B- wires from the stepper motor to the module connections 1, 2, 13 and 14 respectively. Place the jumpers included with the L298N module over the pairs at module points 7 and 12. Then connect the power supply as required to points 4 (positive) and 5 (negative/GND).

Once again if your stepper motor’s power supply is less than 12V, fit the jumper to the module at point 3 which gives you a neat 5V power supply for your Arduino.

Next, connect L298N module pins IN1, IN2, IN3 and IN4 to Arduino digital pins D8, D9, D10 and D11 respectively. Finally, connect Arduino GND to point 5 on the module, and Arduino 5V to point 6 if sourcing 5V from the module.

Controlling the stepper motor from your sketches is very simple, thanks to the Stepper Arduino library included with the Arduino IDE as standard.

To demonstrate your motor, simply load the stepper_oneRevolution sketch that is included with the Stepper library, for example:

Finally, check the value for

	const int stepsPerRevolution = 200;

in the sketch and change the 200 to the number of steps per revolution for your stepper motor, and also the speed which is preset to 60 RPM in the following line:

	myStepper.setSpeed(60);

Now you can save and upload the sketch, which will send your stepper motor around one revolution, then back again. This is achieved with the function

	myStepper.step(stepsPerRevolution); // for clockwise
	myStepper.step(-stepsPerRevolution); // for anti-clockwise

Finally, a quick demonstration of our test hardware is shown in the following video:

So there you have it, an easy an inexpensive way to control motors with your Arduino or compatible board. And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a fourth printing!) “Arduino Workshop”.

Learn how to use inexpensive L298N motor control modules to drive DC and stepper motors with Arduino. This is chapter fifty-nine of our huge Arduino tutorial series.

You don’t have to spend a lot of money to control motors with an Arduino or compatible board. After some hunting around we found a neat motor control module based on the L298N H-bridge IC that can allows you to control the speed and direction of two DC motors, or control one bipolar stepper motor with ease.

The L298N H-bridge module can be used with motors that have a voltage of between 5 and 35V DC. With the module used in this tutorial, there is also an onboard 5V regulator, so if your supply voltage is up to 12V you can also source 5V from the board.

So let’s get started!

First we’ll run through the connections, then explain how to control DC motors then a stepper motor. At this point, review the connections on the L298N H-bridge module.

Consider the following image – match the numbers against the list below the image:

1. DC motor 1 “+” or stepper motor A+
2. DC motor 1 “-” or stepper motor A-
3. 12V jumper – remove this if using a supply voltage greater than 12V DC. This enables power to the onboard 5V regulator
4. Connect your motor supply voltage here, maximum of 35V DC. Remove 12V jumper if >12V DC
5. GND
6. 5V output if 12V jumper in place, ideal for powering your Arduino (etc)
7. DC motor 1 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
8. IN1
9. IN2
10. IN3
11. IN4
12. DC motor 2 enable jumper. Leave this in place when using a stepper motor. Connect to PWM output for DC motor speed control.
13. DC motor 2 “+” or stepper motor B+
14. DC motor 2 “-” or stepper motor B-

Controlling DC Motors

To control one or two DC motors is quite easy with the L298N H-bridge module. First connect each motor to the A and B connections on the L298N module. If you’re using two motors for a robot (etc) ensure that the polarity of the motors is the same on both inputs. Otherwise you may need to swap them over when you set both motors to forward and one goes backwards!

Next, connect your power supply – the positive to pin 4 on the module and negative/GND to pin 5. If you supply is up to 12V you can leave in the 12V jumper (point 3 in the image above) and 5V will be available from pin 6 on the module. This can be fed to your Arduino’s 5V pin to power it from the motors’ power supply. Don’t forget to connect Arduino GND to pin 5 on the module as well to complete the circuit.

Now you will need six digital output pins on your Arduino, two of which need to be PWM (pulse-width modulation) pins. PWM pins are denoted by the tilde (“~”) next to the pin number, for example:

Finally, connect the Arduino digital output pins to the driver module. In our example we have two DC motors, so digital pins D9, D8, D7 and D6 will be connected to pins IN1, IN2, IN3 and IN4 respectively. Then connect D10 to module pin 7 (remove the jumper first) and D5 to module pin 12 (again, remove the jumper).

The motor direction is controlled by sending a HIGH or LOW signal to the drive for each motor (or channel). For example for motor one, a HIGH to IN1 and a LOW to IN2 will cause it to turn in one direction, and  a LOW and HIGH will cause it to turn in the other direction.

However the motors will not turn until a HIGH is set to the enable pin (7 for motor one, 12 for motor two). And they can be turned off with a LOW to the same pin(s). However if you need to control the speed of the motors, the PWM signal from the digital pin connected to the enable pin can take care of it.

This is what we’ve done with the DC motor demonstration sketch. Two DC motors and an Arduino Uno are connected as described above, along with an external power supply. Then enter and upload the following sketch:

// connect motor controller pins to Arduino digital pins
// motor one
int enA = 10;
int in1 = 9;
int in2 = 8;
// motor two
int enB = 5;
int in3 = 7;
int in4 = 6;
void setup()
{
  // set all the motor control pins to outputs
  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
}
void demoOne()
{
  // this function will run the motors in both directions at a fixed speed
  // turn on motor A
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);
  // set speed to 200 out of possible range 0~255
  analogWrite(enA, 200);
  // turn on motor B
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);
  // set speed to 200 out of possible range 0~255
  analogWrite(enB, 200);
  delay(2000);
  // now change motor directions
  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH); 
  delay(2000);
  // now turn off motors
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
}
void demoTwo()
{
  // this function will run the motors across the range of possible speeds
  // note that maximum speed is determined by the motor itself and the operating voltage
  // the PWM values sent by analogWrite() are fractions of the maximum speed possible 
  // by your hardware
  // turn on motors
  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH); 
  // accelerate from zero to maximum speed
  for (int i = 0; i < 256; i++)
  {
    analogWrite(enA, i);
    analogWrite(enB, i);
    delay(20);
  } 
  // decelerate from maximum speed to zero
  for (int i = 255; i >= 0; --i)
  {
    analogWrite(enA, i);
    analogWrite(enB, i);
    delay(20);
  } 
  // now turn off motors
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);  
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);  
}
void loop()
{
  demoOne();
  delay(1000);
  demoTwo();
  delay(1000);
}

So what’s happening in that sketch? In the function demoOne() we turn the motors on and run them at a PWM value of 200. This is not a speed value, instead power is applied for 200/255 of an amount of time at once.

Then after a moment the motors operate in the reverse direction (see how we changed the HIGHs and LOWs in thedigitalWrite() functions?).

To get an idea of the range of speed possible of your hardware, we run through the entire PWM range in the function demoTwo() which turns the motors on and them runs through PWM values zero to 255 and back to zero with the two for loops.

Finally this is demonstrated in the following video – using our well-worn tank chassis with two DC motors:

Controlling a Stepper Motor

Stepper motors may appear to be complex, but nothing could be further than the truth. In this example we control a typical NEMA-17 stepper motor that has four wires:

It has 200 steps per revolution, and can operate at at 60 RPM. If you don’t already have the step and speed value for your motor, find out now and you will need it for the sketch.

The key to successful stepper motor control is identifying the wires – that is which one is which. You will need to determine the A+, A-, B+ and B- wires. With our example motor these are red, green, yellow and blue. Now let’s get the wiring done.

Connect the A+, A-, B+ and B- wires from the stepper motor to the module connections 1, 2, 13 and 14 respectively. Place the jumpers included with the L298N module over the pairs at module points 7 and 12. Then connect the power supply as required to points 4 (positive) and 5 (negative/GND).

Once again if your stepper motor’s power supply is less than 12V, fit the jumper to the module at point 3 which gives you a neat 5V power supply for your Arduino.

Next, connect L298N module pins IN1, IN2, IN3 and IN4 to Arduino digital pins D8, D9, D10 and D11 respectively. Finally, connect Arduino GND to point 5 on the module, and Arduino 5V to point 6 if sourcing 5V from the module.

Controlling the stepper motor from your sketches is very simple, thanks to the Stepper Arduino library included with the Arduino IDE as standard.

To demonstrate your motor, simply load the stepper_oneRevolution sketch that is included with the Stepper library, for example:

Finally, check the value for

const int stepsPerRevolution = 200;

in the sketch and change the 200 to the number of steps per revolution for your stepper motor, and also the speed which is preset to 60 RPM in the following line:

myStepper.setSpeed(60);

Now you can save and upload the sketch, which will send your stepper motor around one revolution, then back again. This is achieved with the function

myStepper.step(stepsPerRevolution); // for clockwise
	myStepper.step(-stepsPerRevolution); // for anti-clockwise

Finally, a quick demonstration of our test hardware is shown in the following video:

So there you have it, an easy an inexpensive way to control motors with your Arduino or compatible board. And if you enjoyed this article, or want to introduce someone else to the interesting world of Arduino – check out my book (now in a fourth printing!) “Arduino Workshop”.

The post Tutorial – L298N Dual Motor Controller Modules and Arduino appeared first on tronixstuff.