ArduinoYun hardware introduction and ArduinoYun hardware tutorial

ArduinoYun hardware introduction and ArduinoYun hardware tutorial
ArduinoYun introduction to ArduinoYun power outlet

Arduino Yun has two outlets which can be divided into three types: power supply, digital I/O, and analog input. The power supply is mainly concentrated in part 1.7.

Figure 1.7 Power Supply concentration

There are also two locations in the 1.8 format.

Figure 1.8 Power Supply Section

The following describes the names and meanings in the corresponding graph:

• Q 3 GND: ground. Although they are distributed in different locations, they all have the same functions;

• Q Vin: power input. It can be used to power the entire board, similar to the power supply function of MicroUSB. However, note that this port will bypass the protection circuit. If the pressure is over, the Board will be destroyed. Therefore, do not use this method when you have no confidence in your own strength. Normally. USB Power Supply can meet most of the needs;

• Q 5 V: 5 V power output, which is the voltage used by most chips;

• Q 3.3 V: 3.3V voltage output. Some chips need this voltage, but note that it can provide up to 50ma of current;

• Q RESET: RESET ATmega32u4, which is usually used by the clipboard;

• Q IOREF: Operation Reference Voltage, which is used by the detection board to select the operation voltage (3.3V or 5 V );

• Q AREF: Reference Voltage for analog operations. It is used for Analog-to-analog conversion (Conversion between analog and digital signals ). The analog input port provides a resolution of 10 bits, that is, 1024 different values (10 power of 2 ). Assume that AREF is 5 V and input is 2.5 V, the result of the modulus conversion is 1024 * (2.5/5) = 512; if AREF is 10 V, the same 256 V Conversion Result is.

ArduinoYun digital IO

Digital I/O is the input and output of digital signals. All 20 ports can be used as digital I/O. They are mainly distributed in two parts, 1.9 and 1.10.

Figure 1.9 digital I/O section

Figure 1.10 digital I/O section

Digital IO is used to exchange digital signals. A digital signal has only two States: high and low. The data processed in the computer is digital signals, including text, video, and images. In the peripheral devices of Arduino, digital devices include switches, LED Lattice devices, and integrated circuits.

Simulated input of ArduinoYun

The analog IO corresponds to the digital IO, which is used to exchange analog signals, and the analog signals change continuously. The most common example of analog signals is indoor temperature and humidity. Their changes are continuous without sudden changes. The analog input accepts a continuously changing voltage input, and Yun has 12 analog inputs, 6 of which are concentrated in the part shown in 1.11.

Figure 1.11 simulated Input

The remaining 6 reusable 4, 6, 8, 9, 10, and 12, as shown in Figure 1.12.

Figure 1.12 simulated Input

During use of analog input, you can use the front A identifier, that is, 12 analog input ports can pass through A0 ~ A11 ID. Where, A0 ~ A5 corresponds to A0 ~ in Figure 1.11 ~ A5; A6 ~ A11 corresponds to 4 (A6), 6 (A7), 8 (A8), 9 (A9), 10 (A10), and 12 (A11 ).

PWM of ArduinoYun

PWM is the abbreviation of Pulse Width Modulation (Pulse Width Modulation. It uses a microprocessor's digital output to control analog circuits, that is, it uses digital signals to simulate analog signals. For example, PWM can drive the speaker to make different tones of sound. The sockets with PWM are very easy to differentiate, and their port numbers are all followed by "~" Symbol, as shown in 1.13.

Figure 1.13 PWM Port

We can see that they are ports 3, 5, 6, 9, 10, and 11, respectively. There are 6 in total.

Serial of ArduinoYun

Serial is the Serial port. Port 0 and Port 1 are reused. Port 0 serves as the receiving end and Port 1 serves as the sending end. This can be seen from the arrow direction in Figure 1.14.

Figure1.14 Serial

The downward arrow indicates that the data enters the port, and the upward arrow indicates that the data is sent from the port.

TWI of ArduinoYun

TWI is the abbreviation of Two-Wire Interface. It implements the same functions as the I2C (Inter-Integrated Circuit) bus. However, due to the copyright protection and registered trademark of I2C, so Atmel represents it with TWI. This method only requires two lines: SDA (Serial Data) and SCL (serial clock ). In Arduino Yun, ports 2 and 3 are reused as SDA, and ports 3 are used as SCL.

ArduinoYun SPI

SPI is the abbreviation of Serial Peripheral Interface. It is a synchronous Serial Peripheral Interface that uses the ICSP header (Number 6 in Figure 1.4 ).

External interruption of ArduinoYun

Interrupt allows the processor to run more efficiently. Yun has five external interruptions. They reuse ports 3, 2, 0, 1, and 7 respectively. The interrupt details will be introduced in chapter 4th, which will not be described here.

Two microprocessor specifications of ArduinoYun

Because Yun has two microprocessors, two tables are used to list their specifications. The specifications of the AVR Arduino microcontroller are shown in Table 1.1 and that of the Linux microprocessor is shown in Table 1.2.

Table 1.1 AVR Arduino microprocessor specifications

Here, we need to note that the parameters are "Maximum supply current of the IO port" and "Maximum supply current of the 3.3V port ". If the maximum value is exceeded, the Board may be damaged. Therefore, do not use IO ports to drive relays, DC motors, and other high-power devices.

Table 1.2 Linux microprocessor specifications

For Linux, we need to pay attention to the parameter "Flash Memory" capacity, 16 MB capacity limit it can not store too many multimedia files, however, installing some common software is sufficient.

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