开始学习
Wio Terminal 读取树莓派状态
Demo 概述
这个 Demo 展示了如何通过 USB 接口读取树莓派的系统状态信息，并显示在 Wio Terminal 的 LCD 屏幕上。具体来说，Wio Terminal 的 USB 为 Client 模式，树莓派的 USB 为 Host 模式，并将 Wio Terminal 识别为一个 USB serial 设备，对应 /dev/tty* 设备节点。
硬件材料
- 1 x Raspberry Pi
- 1 x Wio Terminal
- 1 x USB Type-C 连接线
安装依赖库
本示例 Demo 依赖 LCD 库和 Free_Fonts.h 字体库：
LCD库在安装 Seeed SAMD Boards 库时已经包含了，大家可以参考 Wio Terminal 开发环境。Free_Fonts.h库提供了一些免费字体，可以点击这里下载，并将它放在 Arduino 工程中。
树莓派程序
树莓派需要运行下面这个 Python 程序，它的功能是定时收集系统的一些状态信息，并打包发送给 Wio Terminal。默认的 USB 串口节点应该是 /dev/ttyACM0，如果不对请自行修改。
import os
import time
import serial
# Settings for reading from Arduino Serial
serialPort= "/dev/ttyACM0" #Change it to your Serial Port, Check in Arudino IDE
baudRate = 115200
ser = serial.Serial(serialPort, baudRate, timeout=0.5)
time.sleep(2)
# Return CPU temperature as a character string
def getCPUtemperature():
res = os.popen('vcgencmd measure_temp').readline()
return(res.replace("temp=","").replace("'C\n",""))
# Return RAM information (unit=kb) in a list
# Index 0: total RAM
# Index 1: used RAM
# Index 2: free RAM
def getRAMinfo():
p = os.popen('free')
i = 0
while 1:
i = i + 1
line = p.readline()
if i==2:
return(line.split()[1:4])
# Return % of CPU used by user as a character string
def getCPUuse():
return(str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip()))
# Return information about disk space as a list (unit included)
# Index 0: total disk space
# Index 1: used disk space
# Index 2: remaining disk space
# Index 3: percentage of disk used
def getDiskSpace():
p = os.popen("df -h /")
i = 0
while 1:
i = i +1
line = p.readline()
if i==2:
return(line.split()[1:5])
def main():
while True:
# CPU informatiom
CPU_temp = getCPUtemperature()
CPU_usage = getCPUuse()
# RAM information
# Output is in kb, here I convert it in Mb for readability
RAM_stats = getRAMinfo()
RAM_total = str(round(int(RAM_stats[0]) / 1000,1))
RAM_used = str(round(int(RAM_stats[1]) / 1000,1))
RAM_free = str(round(int(RAM_stats[2]) / 1000,1))
# Disk information
DISK_stats = getDiskSpace()
DISK_total = DISK_stats[0]
DISK_used = DISK_stats[1]
DISK_perc = DISK_stats[3]
temp=ser.write(str.encode(CPU_temp+' '+CPU_usage))
data=ser.write(str.encode(CPU_temp+':'+CPU_usage+':'+RAM_total+':'+RAM_used+':'+RAM_free+':'+DISK_total+':'+DISK_used+':'+DISK_perc))
ser.flush()
time.sleep(2)
print('')
print('CPU Temperature = '+CPU_temp)
print('CPU Use = '+CPU_usage)
print('')
print('RAM Total = '+str(RAM_total)+' MB')
print('RAM Used = '+str(RAM_used)+' MB')
print('RAM Free = '+str(RAM_free)+' MB')
print('')
print('DISK Total Space = '+str(DISK_total)+'B')
print('DISK Used Space = '+str(DISK_used)+'B')
print('DISK Used Percentage = '+str(DISK_perc))
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt:
if ser != None:
ser.close()
Arduino 程序
#include"TFT_eSPI.h"
#include"Free_Fonts.h" //include the header file
TFT_eSPI tft;
char buffer[100];
String CPU_temp, CPU_usage, Ram_total, Ram_used, Ram_free, Disk_total, Disk_used, Disk_Per;
const unsigned char ram[] = {
0x00, 0xC3, 0x18, 0xC3, 0x00, 0x00, 0xE7, 0x18, 0xE7, 0x00, 0x00, 0xC3,
0x18, 0xC3, 0x00, 0x00, 0xC3, 0x18, 0xC3, 0x00, 0x00, 0xE7, 0x18, 0xE7,
0x00, 0x80, 0xFF, 0xFF, 0xFF, 0x01, 0xC0, 0xFF, 0xFF, 0xFF, 0x03, 0xE0,
0x01, 0x00, 0x80, 0x07, 0xFF, 0x00, 0x00, 0x00, 0xFF, 0x7F, 0x00, 0x00,
0x00, 0xFE, 0x72, 0xF0, 0xFF, 0x0F, 0x4E, 0x60, 0xF8, 0xFF, 0x1F, 0x06,
0x60, 0x3C, 0x00, 0x3C, 0x06, 0x72, 0x1C, 0x00, 0x38, 0x4E, 0x7F, 0x0C,
0x00, 0x30, 0xFE, 0x7F, 0x0C, 0x00, 0x30, 0xFE, 0x60, 0x0C, 0x00, 0x30,
0x06, 0x60, 0x0C, 0x00, 0x30, 0x06, 0x60, 0x0C, 0x00, 0x30, 0x06, 0x7F,
0x0C, 0x00, 0x30, 0xFE, 0x7F, 0x0C, 0x00, 0x30, 0xFE, 0x60, 0x0C, 0x00,
0x30, 0x06, 0x60, 0x0C, 0x00, 0x30, 0x06, 0x60, 0x0C, 0x00, 0x30, 0x06,
0x7F, 0x0C, 0x00, 0x30, 0xFE, 0x7F, 0x0C, 0x00, 0x30, 0xFE, 0x72, 0x1C,
0x00, 0x38, 0x4E, 0x60, 0x3C, 0x00, 0x3C, 0x06, 0x60, 0xF8, 0xFF, 0x1F,
0x06, 0x72, 0xF0, 0xFF, 0x0F, 0x4E, 0x7F, 0x00, 0x00, 0x00, 0xFE, 0xFF,
0x00, 0x00, 0x00, 0xFF, 0xE0, 0x01, 0x00, 0x80, 0x07, 0xC0, 0xFF, 0xFF,
0xFF, 0x03, 0x80, 0xFF, 0xFF, 0xFF, 0x01, 0x00, 0xE7, 0x18, 0xE7, 0x00,
0x00, 0xC3, 0x18, 0xC3, 0x00, 0x00, 0xC3, 0x18, 0xC3, 0x00, 0x00, 0xE7,
0x18, 0xE7, 0x00, 0x00, 0xC3, 0x18, 0xC3, 0x00, };
const unsigned char cpu[] = {
0x00, 0x42, 0x18, 0x42, 0x00, 0x00, 0x42, 0x18, 0x42, 0x00, 0x00, 0x42,
0x18, 0x42, 0x00, 0x00, 0x42, 0x18, 0x42, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0xFF, 0xFF, 0xFF, 0x01, 0xC0,
0x00, 0x00, 0x00, 0x03, 0x40, 0x00, 0x00, 0x00, 0x02, 0x4F, 0x00, 0x00,
0x00, 0xF2, 0x40, 0x00, 0x00, 0x00, 0x02, 0x40, 0x00, 0x00, 0x00, 0x02,
0x40, 0x00, 0x00, 0x00, 0x02, 0x40, 0xF0, 0xFF, 0x0F, 0x02, 0x4F, 0xF8,
0xFF, 0x1F, 0xF2, 0x40, 0x18, 0x00, 0x18, 0x02, 0x40, 0xD8, 0xBD, 0x1E,
0x02, 0x40, 0x78, 0xBC, 0x1E, 0x02, 0x40, 0x78, 0xA4, 0x1E, 0x02, 0x4F,
0x78, 0xBC, 0x1E, 0xF2, 0x4F, 0x78, 0xBC, 0x1E, 0xF2, 0x40, 0x78, 0x84,
0x1E, 0x02, 0x40, 0x78, 0x84, 0x1E, 0x02, 0x40, 0xD8, 0x85, 0x1B, 0x02,
0x40, 0x18, 0x00, 0x18, 0x02, 0x4F, 0xF8, 0xFF, 0x1F, 0xF2, 0x40, 0xF0,
0xFF, 0x0F, 0x02, 0x40, 0x00, 0x00, 0x00, 0x02, 0x40, 0x00, 0x00, 0x00,
0x02, 0x40, 0x00, 0x00, 0x00, 0x02, 0x4F, 0x00, 0x00, 0x00, 0xF2, 0x40,
0x00, 0x00, 0x00, 0x02, 0xC0, 0x00, 0x00, 0x00, 0x03, 0x80, 0xFF, 0xFF,
0xFF, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x42, 0x18, 0x42, 0x00, 0x00, 0x42, 0x18, 0x42, 0x00, 0x00, 0x42,
0x18, 0x42, 0x00, 0x00, 0x42, 0x18, 0x42, 0x00, };
const unsigned char disk[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0xF8, 0xFF, 0xFF, 0xFF, 0x03, 0xFC, 0xFB,
0xFF, 0xDF, 0x06, 0x06, 0x02, 0x00, 0x40, 0x0C, 0x06, 0x02, 0x00, 0x5F,
0x18, 0x06, 0x02, 0x00, 0x51, 0x30, 0x06, 0x02, 0x00, 0x59, 0x60, 0x06,
0x02, 0x00, 0x59, 0x40, 0x06, 0x02, 0x00, 0x59, 0x60, 0x06, 0x02, 0x00,
0x59, 0x60, 0x06, 0x02, 0x00, 0x59, 0x60, 0x06, 0x02, 0x00, 0x5F, 0x60,
0x06, 0x02, 0x00, 0x40, 0x60, 0x06, 0xFE, 0xFF, 0x7F, 0x60, 0x06, 0x00,
0x00, 0x00, 0x60, 0x06, 0x00, 0x00, 0x00, 0x60, 0x06, 0x00, 0x00, 0x00,
0x60, 0x06, 0x00, 0x00, 0x00, 0x60, 0x06, 0x00, 0x00, 0x00, 0x60, 0xC6,
0xFF, 0xFF, 0xFF, 0x63, 0x66, 0x00, 0x00, 0x00, 0x66, 0x26, 0x00, 0x00,
0x00, 0x64, 0x26, 0x00, 0x00, 0x00, 0x64, 0x26, 0x00, 0x00, 0x00, 0x64,
0x26, 0xFC, 0xFF, 0x3F, 0x64, 0x26, 0xFC, 0xFF, 0x3F, 0x64, 0x26, 0x00,
0x00, 0x00, 0x64, 0x26, 0x00, 0x00, 0x00, 0x64, 0x26, 0xFC, 0xFF, 0x3F,
0x64, 0x26, 0x00, 0x00, 0x00, 0x64, 0x26, 0x00, 0x00, 0x00, 0x64, 0x26,
0x00, 0x00, 0x00, 0x64, 0x26, 0xFC, 0xFF, 0x3F, 0x64, 0x26, 0x00, 0x00,
0x00, 0x64, 0x26, 0x00, 0x00, 0x00, 0x64, 0x26, 0x00, 0x00, 0x00, 0x64,
0x26, 0x00, 0x00, 0x00, 0x64, 0xEC, 0xFF, 0xFF, 0xFF, 0x37, 0xF8, 0xFF,
0xFF, 0xFF, 0x1F, 0x00, 0x00, 0x00, 0x00, 0x00, };
String getStringPartByNr(String data, char separator, int index)
{
// spliting a string and return the part nr index
// split by separator
int stringData = 0; //variable to count data part nr
String dataPart = ""; //variable to hole the return text
for(int i = 0; i<data.length()-1; i++) { //Walk through the text one letter at a time
if(data[i]==separator) {
//Count the number of times separator character appears in the text
stringData++;
}else if(stringData==index) {
//get the text when separator is the rignt one
dataPart.concat(data[i]);
}else if(stringData>index) {
//return text and stop if the next separator appears - to save CPU-time
return dataPart;
break;
}
}
//return text if this is the last part
return dataPart;
}
void setup() {
// initialize serial ports:
Serial.begin(115200);
Serial.flush();
tft.begin();
tft.setRotation(3);
//Homescreen when there is no data
tft.fillScreen(TFT_WHITE);
while(1) {
HomeScreen();
if (Serial.available())
break;
}
}
void loop() {
// Try to get the data from serial port
if (Serial.available() > 0) {
int index = 0;
int numChar = Serial.available();
if (numChar>50) {
numChar=50;
}
memset(buffer, 0, sizeof(buffer));
while (numChar--) {
buffer[index++] = Serial.read();
}
CPU_temp = getStringPartByNr(buffer, '.', 0);
CPU_usage = getStringPartByNr(buffer, ':', 1);
Ram_total = getStringPartByNr(buffer, ':', 2);
Ram_used = getStringPartByNr(buffer, ':', 3);
Ram_free = getStringPartByNr(buffer, ':', 4);
Disk_total = getStringPartByNr(buffer, ':', 5);
Disk_used = getStringPartByNr(buffer, ':', 6);
Disk_Per = getStringPartByNr(buffer, ':', 7);
}
//checking the last piece of data is not empty
if (Disk_Per != "") {
TempScreen();
delay(2000);
RamScreen();
delay(2000);
DiskScreen();
delay(2000);
}
}
void TempScreen() {
tft.fillScreen(TFT_BLACK);
tft.setTextColor(TFT_WHITE);
tft.setTextSize(1);
tft.setFreeFont(FSSB12); //select Free, Sans, Bold, Oblique, 12pt.
tft.drawString("Raspberry CPU Data",40,17);
tft.drawFastHLine(0,45,320,TFT_RED);
tft.drawFastHLine(0,46,320,TFT_RED);
tft.drawFastHLine(0,47,320,TFT_RED);
tft.drawRoundRect(34,66,82,32,5,TFT_WHITE);
tft.fillRoundRect(35,67,80,30,5,TFT_DARKGREY);
tft.setFreeFont(FMB12);
tft.setTextColor(TFT_WHITE);
tft.drawString("TEMP:",40,70);
tft.drawRoundRect(34,116,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,117,90,30,5,TFT_DARKGREY);
tft.drawString("USAGE:",40,120);
tft.drawFastHLine(0,220,320,TFT_RED);
tft.drawFastHLine(0,221,320,TFT_RED);
tft.drawFastHLine(0,222,320,TFT_RED);
tft.fillCircle(15,80, 5, TFT_DARKGREY);
tft.fillCircle(15,130, 5, TFT_DARKGREY);
tft.drawCircle(15,80,6,TFT_WHITE);
tft.drawCircle(15,130,6,TFT_WHITE);
tft.setTextColor(TFT_WHITE);
tft.drawString(CPU_temp+'C',130,70);
tft.drawString(CPU_usage+'%',130,120);
tft.drawXBitmap(245,110,cpu, 40, 40, TFT_DARKGREY);
}
void RamScreen() {
tft.fillScreen(TFT_BLACK);
tft.setTextColor(TFT_WHITE);
tft.setTextSize(1);
tft.setFreeFont(FSSB12); //select Free, Sans, Bold, Oblique, 12pt.
tft.drawString("Raspberry RAM Data",40,17);
tft.drawFastHLine(0,45,320,TFT_BLUE);
tft.drawFastHLine(0,46,320,TFT_BLUE);
tft.drawFastHLine(0,47,320,TFT_BLUE);
tft.drawRoundRect(34,66,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,67,90,30,5,TFT_PINK);
tft.setFreeFont(FMB12);
tft.setTextColor(TFT_WHITE);
tft.drawString("TOTAL:",40,70);
tft.drawRoundRect(34,116,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,117,90,30,5,TFT_PINK);
tft.drawString("USED:",40,120);
tft.drawRoundRect(34,166,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,167,90,30,5,TFT_PINK);
tft.drawString("FREE:",40,170);
tft.drawFastHLine(0,220,320,TFT_BLUE);
tft.drawFastHLine(0,221,320,TFT_BLUE);
tft.drawFastHLine(0,222,320,TFT_BLUE);
tft.fillCircle(15,80, 5, TFT_PINK);
tft.fillCircle(15,130, 5, TFT_PINK);
tft.fillCircle(15,180, 5, TFT_PINK);
tft.drawCircle(15,80,6,TFT_WHITE);
tft.drawCircle(15,130,6,TFT_WHITE);
tft.drawCircle(15,180,6,TFT_WHITE);
tft.setTextColor(TFT_WHITE);
tft.drawString(Ram_total+"MB",130,70);
tft.drawString(Ram_used+"MB", 130,120);
tft.drawString(Ram_free+"MB", 130,170);
tft.drawXBitmap(245,110,ram, 40, 40, TFT_PINK);
}
void DiskScreen() {
tft.fillScreen(TFT_BLACK);
tft.setTextColor(TFT_WHITE);
tft.setTextSize(1);
tft.setFreeFont(FSSB12);
tft.drawString("Raspberry Disk Data",35,17);
tft.drawFastHLine(0,45,320,TFT_ORANGE);
tft.drawFastHLine(0,46,320,TFT_ORANGE);
tft.drawFastHLine(0,47,320,TFT_ORANGE);
tft.drawRoundRect(34,66,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,67,90,30,5,TFT_DARKCYAN);
tft.setFreeFont(FMB12);
tft.drawString("TOTAL:",40,70);
tft.drawRoundRect(34,116,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,117,90,30,5,TFT_DARKCYAN);
tft.drawString("USED:",40,120);
tft.drawRoundRect(34,166,92,32,5,TFT_WHITE);
tft.fillRoundRect(35,167,90,30,5,TFT_DARKCYAN);
tft.drawString("PERC.:",40,170);
tft.drawFastHLine(0,220,320,TFT_ORANGE);
tft.drawFastHLine(0,221,320,TFT_ORANGE);
tft.drawFastHLine(0,222,320,TFT_ORANGE);
tft.fillCircle(15,80, 5, TFT_DARKCYAN);
tft.fillCircle(15,130, 5, TFT_DARKCYAN);
tft.fillCircle(15,180, 5, TFT_DARKCYAN);
tft.drawCircle(15,80,6,TFT_WHITE);
tft.drawCircle(15,130,6,TFT_WHITE);
tft.drawCircle(15,180,6,TFT_WHITE);
if (Disk_Per != 0) {
int perc = atoi(Disk_Per.c_str());
float ratio = perc*(0.01) * 30;
tft.drawRect(180,168,10,30,TFT_WHITE);
tft.fillRect(180,(168+(30-(int)ratio)),10,(int)ratio,TFT_WHITE);
}
tft.drawString(Disk_total+'B',130,70);
tft.drawString(Disk_used+'B', 130,120);
tft.drawString(Disk_Per+'%', 130,170);
tft.drawXBitmap(245,110,disk, 40, 40, TFT_DARKCYAN);
}
void HomeScreen() {
tft.setFreeFont(FSSB9);
tft.setTextColor(TFT_BLACK);
tft.drawString("Starting...", 120,120);
}