NANO UNO Multipurpose Expansion Board Yellow Pin Multipurpose Expansion Module Red Board
The UNO R3 is the latest easy-to-use open-source controller launched in 2012, with no significant hardware changes compared to UNO. The biggest difference is the USB to serial circuit, which uses an ATMega16U2 microcontroller. As a result, the cost has also increased, and the software part remains the same as before without significant changes.
Function:
1. Pin change: Two I2C pins (SDA and SCL, only a copy of 4 and 5, not an additional I2C interface) have been added next to the AREF pin. In addition, two pins have been added next to RESET, one is IOREF, which allows the expansion board to adapt to the onboard voltage. This pin only tells the current onboard voltage of the expansion board (for example, UNO is 5V, which can be seen as a copy of the power pin and does not provide a level up pull), The other is a placeholder pin to be used in the future.
2. A more stable RESET circuit. The position of the RESET key has also changed and has been moved to the corner of the board near the USB interface, making it easier to press.
3. ATmega16U2 replaces 8U2, which does not mean that having a 16K flash R3 can make your code run faster. This update is for USB interface chip services, theoretically allowing UNO to simulate USB HID, such as MIDI/Joystick/Keyboard
controller
ATMEGA328P
input pins
6 (2 of which can serve as I2C interfaces)
Digital IO
14 (of which 6 can be used as PWM ports)
Flash memory capacity
32KB (of which 2KB has been used as Bootloader space)
USB power supply voltage
5V
SRAM
2KB
External power supply voltage (recommended value)
7-12
EEPROM
1KB
Maximum current of external power supply
1A
clock frequency
16MHz
Maximum current of IO port
40mA
weight
60g
Operating voltage
5V
size
75X54X15mm
After receiving the board, the first step is to preliminarily confirm whether it is working properly. Connect the board to the computer using a USB cable. At this time, the green power light (ON) on the right should be on, and the yellow light (L) next to ATmega16U2 is also flashing rapidly. After a few seconds, this LED will flash every two seconds because the IDE's built-in process Blink has already been burned before storage (the installation driver will be introduced below).
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Here is a simple project to simulate a simple development process, allowing friends who have not yet entered the open source hardware industry to experience the methods and of using UNO R3 for project and design, as well as its similarities and differences from traditional development methods.
Project objective: One LED flashes every second, which means it lights up for half a second and goes off for half a second.
Programming:
First, from the official website http://.cc/en/Main/Software Download the development environment and select version 1.0 or higher. Here, select version 1.0. After downloading, unzip it to the English path. The software is a hard drive version and does not require installation.
Open the. exe in the -1.0 directory.
The program required to write this project is to cycle through pin 13, which is connected to the green LED on the motherboard, continuously changing its high and low levels, as shown in the following figure.
Note: The program must include two functions: setup() and loop(). setup() is a function that is executed upon system startup, followed by the loop() function, which is executed in a loop.
After programming, save to the newly created directory MyProject in the -1.0 directory (the name depends on preference), and the file name is blink.
Warm reminder about programming
Most people think that programming in this development environment is too cumbersome and the user experience is not good enough (such as not being able to automatically recognize defined variables, macros, functions, etc.), so we can use an external editor. Click on Preferences in the File dropdown menu, then check the Use external editor option, and click OK to open the project's program file for programming (limited by space, details will not be detailed), as shown in the following figure. It is recommended to use Source 3.5 or notepad++as an external editor. It is only after using it that you will know its usefulness.
