In this article, we will deal with the Arduino Pro Micro, find out its characteristics, applications, advantages over other boards, consider several projects with its use and will definitely create a project on it in the form of a scroller for video editors (or for many other tasks solved by a rotating control ).
Arduino pro micro – compact Arduino board, which costs only 3-4$ in China shos. Link.
Its size is 35*18 mm. Height 4 mm, due to a sticking USB port.
16 digital pins are available for operation (5 of them have PWM), four analog pins and six analog pins combined with digital pins, i2c bus, for connecting compatible modules. There are three GND pins, but only one five-volt power pin. The board has a voltage regulator, so it can accept voltages up to 12 V DC. When applying to the power board more than 6 volts, it must be connected to the RAW pin, 5-6 volts is connected to the VCC.
The thing you should pay attention to on these boards is the lack of a reset button, so you will need to connect your own. It also has a loader mode, which is entered by a long reset and is completed with two short drops. If your device is in bootloader mode, you will not be able to flash sketches on it.
The pinout is on image:
Board is based on microcontroller atmega32u4, it’s cool! It can pretend to be an HID device (human interface device – a keyboard, mouse, joystick, midi keyboard or other devices). Boards Arduino Uno, Mega, Nano do not know how.
There are two versions you can buy – version 5V, 16 MHz and version 3.3 V, 8 MHz. If you do not have a really good reason, I would always take on 5V.
Do not confuse with the Pro Mini. Many people on the network confuse Pro Micro (which has a USB connector) with a Pro Mini (does not have a USB connector). Note the difference in the pictures below. When buying it, be sure to purchase Pro Micro.
For its firmware does not need additional programs and some kind of driver. They are immediately built into the Arduino IDE. There is only one moment. An important moment !!! In the card manager, you must select Leonardo, not pro micro.
Its two main advantages among other boards are the size (with its number of pins) and the ability to be an HID device.
On the basis of this board, you can do everything the same as on Uno. And due to its small size, it is possible to create smart watches, glasses and other wearable electronics on its basis.
In this article, I will show how to make a simple but useful control device.
Today we’ll create an Adobe Premiere timeline footer. With it, you can conveniently navigate the track with the video and scale it.
The device can be made for other programs and tasks, for example:
- Switch between songs or movies in a playlist;
- Scrolling sites, long documents, and presentations;
- Moving through documents and scaling in creative applications;
- Scaling brushes in graphics applications;
- Substitution hotkey combinations.
In the beginning, we solder the encoder to the board. Then we will sew and debug the device, and then we will place everything in the case, which can be printed on a 3D printer.
- Arduino Pro Micro (or Leonardo)
- Rotary encoder
- USB cable
Scheme. We need to connect the encoder to Arduino. Because we will assemble the finished device, it will be convenient to immediately solder the five legs of the encoder into the five digital pins of the Arduino: one to make the ground, one with the power supply and three to handle the presses. Before soldering, it is necessary to evaporate or move the legs. I soldered from 2 to 6 pin, as in the photo.
Programming. To handle turns and clicks, we need an encoder library. The best I’ve ever tried is the library of AlexGaver (link), install the library .zip file through the library manager. In the code, we declare five variables for the legs of the encoder, we enable the encoder library, keyboard, and mouse, we declare the encoder. In the void setup, we turn on the keyboard and mouse modes, give power to the encoder. In the void loop, we check which way the encoder is spinning and whether it is pressed. Execute the appropriate commands:
- Mouse.move(x, y, s); x, у – coordinates of the point where to move the mouse, s – the number of rows scrolled by the mouse wheel.
- Keyboard.press(KEY_LEFT_ALT); – pressing a button on the keyboard.
- Keyboard.releaseAll(); – release all the buttons on the keyboard.
We load the sketch from the computer to the board.
If you want to use other buttons here you can find the description of the keys: https://www.arduino.cc/en/Reference/KeyboardModifiers
Case. For this task, I made the simplest cylinder as the base and the same as the encoder knob. Designed at tinkercad, and the project uploaded on the Thingiverse. Printed with a layer of 0.2 mm. I did this for the first time, so the case did not fit, but I decided not to redo it, and broke one inner wall and filled it with hot glue. Then he covered everything with a hat. I put in the USB wire and started testing the wheel in Adobe Premiere Pro, and in it, I also make a video for you.
A selection of other projects.
USB keyboard for custom labels based on Pro Trinket and Pro Micro https://hackaday.io/project/3502-pro-trinket-usb-keyboard
Dual axis stabilizer for an action camera. Made on Arduino nano, but I would do on pro micro. Also used two servos and tilt sensor. The design is printed on a 3D printer.
Computer blocker on windows RFID tagged
As you can see, I’m a big fan of Pro Micro and I think that the combination of small size, inexpensive and simple programming makes it a fantastic Arduino motherboard for fans.
Do you know more interesting projects or do you have your own? Drop the link in the comments. Also, I will be glad to any comments on the article, I could miss something.