Intel-Galileo

#####使用Galileo的正确姿势:
一定要UART到电脑上( 串口连接方法见Documents/Galileo-UART.txt ), 得知Galileo的准确状态。
板子复位以后启动很慢, 要等好久才可以用Arduino IDE下程序, 否则下载会失败, 提示超时。 #####电源保护 和电源相关的连线, 一定要用杜邦线帽保护好, 因为Galileo的电源引脚都在一起, VCC旁边就是GND, 裸露的杜邦线, 稍微碰下就导致短路, Galileo有严格的电源管理机制, 短路后会立刻重启.(这也是为什么要使用UART准确得到Galileo的状态的原因之一)

##连接

####UART TLL Galileo provides UART TTL (5V/3.3V) serial communication, which is available on digital pin 0 (RX) and 1 (TX).

UART RS-232

In addition, a second UART provides RS-232 support and is connected via a 3.5mm jack.

##I/O基本操作

###Blink/ 点亮LED灯 ###数字电平输出 int led = 13; // Arduino板子的LED一般是pin13 pinMode(led, OUTPUT); // 配置IO引脚的方向 (INPUT, OUTPUT, INPUT_PULLUP) digitalWrite(led, HIGH); // 控制引脚, 输出高/低电平

delay(1000);               // wait for a second, 毫秒级延时

###数字电平读取 int pushButton = 2; pinMode(pushButton, INPUT); int buttonState = digitalRead(pushButton); ###模拟电平读取 int sensorValue = analogRead(A0); //这里的A0是板子上ANALOG IN中的A0~A5. ###模拟电平输出 analogWrite(pin, value);
//value: the duty cycle: between 0 (always off) and 255 (always on).

##DigitalReadSerial/ 串口输出 Intel Galileo只有一个串口, 使用USB连接Galileo板子和电脑时, 板子上有转换电路。
否则, 使用引脚RX(0),TX(1)外接TTL/USB连接电脑。 ###串口配置 Serial.begin(9600); // 配置波特率 Serial.println(buttonState); // 串口输出

##Millis/ 运行时间读取 返回当前的程序的运行毫秒数 绝对值没有多少意义, 一般都是调用两次, 计算差值。

unsigned long time = millis(); 
//Returns Number of milliseconds since the program started (unsigned long)

##Debounce/ 按键去抖 检测到按键按下之后, 记录millis()值.
等待一段之间(定义的去抖阈值),再判断按键,若仍为按下状态,才执行对应操作.

##tonePitchFollower/ 模拟量转方波驱动扬声器 int sensorReading = analogRead(A0); int thisPitch = map(sensorReading, 400, 1000, 120, 1500); tone(9, thisPitch, 10); //tone()在一个引脚产生占空比50%的方波 //第三个参数为持续时间(毫秒), 可选.未声明则直到noTune()才停止. //统一时间只能有一个tone()工作.

##Serial output 串口输出 ###ASCIITable/ 输出语句 Serial.println("hello"); Serial.write(thisByte); Serial.print(thisByte); Serial.print(thisByte, HEX); Serial.print(thisByte, OCT); Serial.print(thisByte, BIN); ##Serial_Read/ 串口交互 brightness = Serial.read(); //注意,串口那里需要设置成不自动添加回车, 否则发完数据会自动发一个回车.

##Arrays/ 数组操作 所有位置都可以改为数组元素操作.

pinMode(ledPins[thisPin], OUTPUT);
digitalWrite(ledPins[thisPin], HIGH);

##ADXL3xx/ 加速计

const int xpin=A3;   // x-axis
const int ypin = A2; // y-axis
const int zpin = A1;

Serial.print(analogRead(xpin));
Serial.print(analogRead(ypin));
Serial.print(analogRead(zpin));

##以太网配置 ####ChatServer/
将Galileo配置成一个局域网中的聊天服务器.
其他电脑可以telnet到此服务器, 输出的消息会广播给所有连接此服务器的客户端。
使用SPI对应的引脚。 Ethernet shield attached to pins 10, 11, 12, 13

#include <SPI.h>
#include <Ethernet.h>

//配置Galileo的Mac地址,IP,gateway, subnet.
byte mac[] = { //Galileo 的以太网端口地址, 板子上有标签98:4F:EE:00:2E:98 
0x98, 0x4F, 0xEE, 0x00, 0x2E, 0x98 };
IPAddress ip(10,42,0, 177);
IPAddress gateway(10,42,0, 1);
IPAddress subnet(255, 255, 255, 00);

// telnet defaults to port 23
EthernetServer server(23);


// initialize the ethernet device
// 支持DHCP -> Ethernet.begin(max);
//            Ethernet.begin(mac, ip); 
Ethernet.begin(mac, ip, gateway, subnet);


  // wait for a new client:
  EthernetClient client = server.available();
  
  // 判断
  if(client)
  {
  ...
  }
  
  server.write(val);
  server.write(buf, len);
  
  
  //具体应用看 Arduino - Ethernet library - Server class / Client class

###EEPROM Intel Galileo的EEPROM是11KB, 所以地址是从0~(11 * 1024 - 1) , 即 0~11263.

#include <EEPROM.h>

//the EEPROM can only hold a value from 0 to 255.
EEPROM.write(address,value);

value = EEPROM.read(address);

UART0串口

How do I access /dev/ttyS0?

参考Programming_GPIO_From_Linux/的文档教程,学会linux下控制Galileo的gpio.

ttyS0对应UART0, 对应引脚IO0,IO1.

查看Galileo IO mapping可知, 相关引脚在linux下为gpio40,gpio41,gpio4.
gpio40是0-RX的选择器控制端口, 其值为0时选择ttyS0, 为1选择gpio50.
gpio41是1-TX的选择器控制端偶, 0->ttyS0, 1->gpio51; gpio4是Level Shifter OE, 要配置其输出为1使能.

导出引脚40,41,4

echo -n 40 > /sys/class/gpio/export 
echo -n 41 > /sys/class/gpio/export 
echo -n 4 > /sys/class/gpio/export 

配置为输出:

echo -n "out" > /sys/class/gpio/gpio40/direction  
echo -n "out" > /sys/class/gpio/gpio41/direction
echo -n "out" > /sys/class/gpio/gpio4/direction

配置输出值:

echo -n "0" > /sys/class/gpio/gpio40/value
echo -n "0" > /sys/class/gpio/gpio41/value 

echo -n "1" > /sys/class/gpio/gpio40/value 

引脚配置完成, 现在ttyS0与UART0的TX0,RX0相连接. 硬件上, 使用TTL转USB模块, RX0(Galileo IO 0) -> TTL(TX), TX0(Galileo IO 1) -> TTL(RX), Galileo GND -> TTL(GND);

USB -> 电脑.

硬件配置完成!

接下来, 在电脑终端中连接对应串口, 波特率默认为9600 Mac OS X下如下:

$ screen /dev/tty.usbserial-A7027C8G 9600

然后, 在Galileo的控制台中,

Galileo -> ttyS0

root@clanton:~# echo "hello, ttyS0, this is Galileo" > /dev/ttyS0 

ttyS0 -> Galileo

root@clanton:~# cat /dev/ttyS0 

这样就变为了输入. 然后在ttyS0端口,也就是电脑中的screen中,进行输出, 信息就会通过串口显示在Galileo中.

UART串口 - Serial

/dev/ttyS0 is the first Quark UART (UART0) and it's the Digital 0 and 1 pins
/dev/ttyS1 is the second Quark UART (UART1) and it's the audio jack one
/dev/ttyGS0 is the virtual serial device created by the Linux cdc-acm driver via the Galileo USB port marked as "USB client".

the Arduino mappings

Serial is routed to the /dev/ttyGS0   
Serial1 is routed to /dev/ttyS0     
Serial2 is not used

Arduino sketch

void setup() {  
}  
void loop() {
delay(5000);  
if(Serial) {  
	Serial.println("This is Serial, must be mapped to /dev/	ttyGS0, i.e. visible in Arduino IDE's Serial Monitor");  
	}  
  else {  
printf("Serial is not ready");  
}  
if(Serial1) {  
Serial1.println("This is Serial1, must be mapped to /dev/ttyS0, i.e. visible on something connected to the Digital pins 0 & 1"); 
} 
else {  
printf("Serial1 is not ready");  
}  
if(Serial2) {  
Serial2.println("This is Serial2, unused, you shouldn't see this anywhere");  
}  
else {  
printf("Serial2 is not ready");  
}  
}  

##SD

The library supports FAT16 and FAT32 file systems on standard SD cards and SDHC cards.
It uses short 8.3 names for files.
The communication between the microcontroller and the SD card uses SPI, which takes place on digital pins 11, 12, and 13 (on most Arduino boards) or 50, 51, and 52 (Arduino Mega). Additionally, another pin must be used to select the SD card.

##SD卡启动linux Booting your board from an SD card(Galileo_GettingStarted.pdf - Page8)

Note: Your SD card must meet the following requirements:

• SD card must be formatted as FAT or FAT32.
• SD card size must be less than 32GB.

---

1. you may need to add a boot partition to your SD card.
   To do this on a Windows machine, perform the following:
   Open a cmd.exe instance as an Administrator. Run diskpart.exe and run the following commands:

    select vol <a>; (where <a> = the drive letter of the SD card)
   
    clean;
    create part primary;
    active;
    format quick label="BOOTME";
    exit
   

2. Copy all files and directories from the zip file to your SD card.

    drwxrwxrwx@ 1 gxp  staff       4096 Apr 13 09:56 boot
    -rwxrwxrwx@ 1 gxp  staff    2113856 Oct  1  2013 bzImage
    -rwxrwxrwx@ 1 gxp  staff    1441609 Oct  1  2013 core-image-minimal-initramfs-clanton.cpio.gz
    -rwxrwxrwx@ 1 gxp  staff  314572800 Oct  1  2013 image-full-clanton.ext3
   

3. Insert the SD card, then power on the board.

###get Ethernet MAC address in a sketch

 Serial.println(system("cat /sys/class/net/eth0/address"));  

or

Serial.println(system("cat /sys/class/net/eth0/address > /dev/ttyGS0"));  

###system()

system()可以执行linux命令行的语句, 并且返回0/256. 成功返回0, 失败返回256.

void setup()
{ 
	 // put your setup code here, to run once:
	Serial.begin(9600);

	Serial.println("\n\nHello world!\n");
	
	Serial.println(system("ifconfig -a"));
	Serial.println(system("ifconfig -all"));
	Serial.println(system("cat /sys/class/net/eth0/address"));
	Serial.println(system("mac_address"));
	Serial.println(system("/sbin/ifconfig"));
}

void loop()
{ }

###开机自启动脚本设置

Galileo/Documents/boot_script

###IO速度研究 Galileo/Documents/IO_speed ###linux GPIO

Galileo/Documents/Programming_GPIO_From_Linux

###Sketch Size Limits Galileo/Documents/sketch_size

###Galileo PWM

Galileo/Documents/PWM