Microsoft Word 二月第一篇V4

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1 智慧家庭 :ARDUINO 物聯網的時 間靈魂 - 網路校時 2016 年 3 月 3 日 二月, 2016 文 \ 曹永忠 前文提要 前文中我們介紹 RTC 時鐘模組, 該模組具備時間功能, 並且為了 斷電時依然可以保留時間, 補足了 Arduino 開發板並沒有內置時鐘 (Internal Clock) 的功能, 正好可以使用該時間模組 如下圖所示, 可以見到 Tiny RTC I2C 時鐘模組的外觀圖, 模組採用 DS1307 晶片, 若讀者需要更詳盡的資料, 請參考拙作 Arduino 投幣計時器 ( 網路 篇 ):Using Arduino to Develop a Timing Controlling Device via Internet ( 曹永忠, 許智誠, & 蔡英德, 2015a, 2015b, 2015c, 2015f; 曹永忠, 許碩芳, 許智誠, & 蔡英德, 2015a, 2015b) 內容關 於 RTC 時鐘模組

2 圖 1 Tiny RTC I2C 時鐘模組 如下圖所示, 我們可以參考時鐘模組之電路連接圖, 先將電路連 接完善後, 攥寫與測試下列 Tiny RTC I2C 時鐘模組測試程式 圖 2 時鐘模組電路連接方式 校時問題 我們發現, 若裝設新的開發版或不同時間點設置新裝置, 我們必 須透過使用者重新設定時間, 或是修改程式, 因為 RTC 時鐘模組的初

3 始化時間是寫在 Arduino 開發版的程式內, 我們必須重新編譯程式, 並上傳程式到 Arduino 開發版, 這樣是非常不方便的, 如果我們具有自動校時的功能, 完全不用使用者插手, 這樣產業化的應用才能更實際, 由於目前網路校時非常的方便, 所以我們可以透過網路校時的方式來實踐這個機制, 或許是一個相當完善的解決方案 連接乙太網路擴充卡 為了能夠上網, 本文使用 W5100 乙太網路擴充卡 ( 曹永忠, 許智誠, & 蔡英德, 2015d, 2015e), 主要特色是把 TCP/IP Protocols (TCP, UDP, ICMP, IPv4 ARP, IGMP, PPPoE, Ethernet) 做在硬體電路上, 減輕了單晶片 (MCU ) 的負擔 ( 也就是 Arduino 開發板的負擔 ) Arduino 程式只要使用 Ethernet Library1 便可以輕易完成連至網際網路的動作 Arduino Ethernet Shield 使用加長型的 Pin header ( 如下圖.(a) & 下圖 (b)), 可以直接插到 Arduino 控制板上 ( 如下圖.(c) & 下圖.(d) & 下圖.(e)), 而且原封不動地保留了 Arduino 控制板的 Pin Layout, 讓使用者可以在它上面疊其它的擴 1 可到 Arduino.cc 的官網 : 下載函式庫與相關範例

4 充板 ( 如下圖.(c) & 下圖.(d) & 下圖 (e)) 比較新的 Ethernet Shield 增加了 micro-sd card 插槽 ( 如下圖.(a)), 可以用來儲存檔案, 你可以用 Arduino 內建的 SD library 來存取板子上的 SD card (a) 正面圖 (b). 背面圖 (c). 堆疊圖 (d). 側面圖 (e). 網路接腳圖 (f). 網路接線圖 圖 3 Ethernet Shield(W5100) 首先, 組立 W5100 以太網路模組是非常容易的一件事, 如下圖所

5 示, 只要將 W5100 以太網路模組堆疊到任何 Arduino 開發板之上就可 以了 圖 4 將 Arduino 開發板與 W5100 以太網路模組堆疊組立 之後, 在將組立好的 W5100 以太網路模組, 如下圖所示, 只要將 USB 線差到 Arduino 開發板, 再將 RJ 45 的網路線一端插到 W5100 以太網路模組, 另一端插到可以上網的集線器 (Switch HUB) 的任何一個區域網路接口 (Lan Port) 就可以了 ( 曹永忠, 許智誠, et al., 2015d, 2015e) 圖 5 接上電源與網路線的 W5100 以太網路模組堆疊卡

6 取得網路校時時間資料 我們將 Arduino 開發板的驅動程式安裝好之後, 我們打開 Arduino 開發板的開發工具 :Sketch IDE 整合開發軟體, 攥寫一段程 式, 如下表所示之網路校時測試程式, 我們就可以透過 W5100 以太網 路模組堆疊卡取得網路校時時間 表 1 網路校時測試程式 /* 網路校時測試程式 (UdpNtpClient) Udp NTP Client Get the time from a Network Time Protocol (NTP) time server Demonstrates use of UDP sendpacket and ReceivePacket For more on NTP time servers and the messages needed to communicate with them, see created 4 Sep 2010 by Michael Margolis modified 9 Apr 2012 by Tom Igoe This code is in the public domain. */ #include <SPI.h> #include <Ethernet.h>

7 #include <EthernetUdp.h> // Enter a MAC address for your controller below. // Newer Ethernet shields have a MAC address printed on a sticker on the shield byte mac[] = { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF ; IPAddress ip(192, 168, 2, 200); //fix ip IPAddress dnserver(168, 95, 1, 1); //dns ip // the router's gateway address: IPAddress gateway(192, 168, 2, 1); //gateway ip // the subnet: IPAddress subnet(255, 255, 255, 0); //sub mask unsigned int localport = 8888; packets // local port to listen for UDP char timeserver[] = "time.nist.gov"; // time.nist.gov NTP server const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message byte packetbuffer[ NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets // A UDP instance to let us send and receive packets over UDP EthernetUDP Udp; int Ntpyr,Ntpmon,Ntpday,Ntphr,Ntpmin,Ntpsec ; void setup() { // Open serial communications and wait for port to open: Serial.begin(9600); while (!Serial) { ; // wait for serial port to connect. Needed for Leonardo only

8 // start Ethernet and UDP if (Ethernet.begin(mac) == 0) { Serial.println("Failed to configure Ethernet using DHCP"); // no point in carrying on, so do nothing forevermore: Ethernet.begin(mac, ip, dnserver, gateway, subnet); Udp.begin(localPort); void loop() { sendntppacket(timeserver); // send an NTP packet to a time server // wait to see if a reply is available delay(1000); if ( Udp.parsePacket() ) { // We've received a packet, read the data from it Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer bytes, //the timestamp starts at byte 40 of the received packet and is four // or two words, long. First, esxtract the two words: unsigned long highword = word(packetbuffer[40], packetbuffer[41]); unsigned long lowword = word(packetbuffer[42], packetbuffer[43]); // combine the four bytes (two words) into a long integer // this is NTP time (seconds since Jan ): unsigned long secssince1900 = highword << 16 lowword; Serial.print("Seconds since Jan = " ); Serial.println(secsSince1900); // now convert NTP time into everyday time: Serial.print("Unix time = "); // Unix time starts on Jan In seconds, that's :

9 const unsigned long seventyyears = UL; // subtract seventy years: unsigned long epoch = secssince seventyyears + 8 * 60*60 ; // print Unix time: Serial.println(epoch); Ntphr = (epoch % 86400L) / 3600 ; Ntpmin = (epoch % 3600) / 60 ; Ntpsec = epoch % 60 ; // print the hour, minute and second: Serial.print("The Taiwan time is "); // UTC is the time at Greenwich Meridian (GMT) Serial.print(print2digits(Ntphr)); // print the hour (86400 equals secs per day) Serial.print(':'); Serial.print(print2digits(Ntpmin)); // print the minute (3600 equals secs per minute) Serial.print(':'); Serial.println(print2digits(Ntpsec)); // print the second // wait ten seconds before asking for the time again delay(10000); // send an NTP request to the time server at the given address unsigned long sendntppacket(char* address) { // set all bytes in the buffer to 0 memset(packetbuffer, 0, NTP_PACKET_SIZE); // Initialize values needed to form NTP request // (see URL above for details on the packets) packetbuffer[0] = 0b ; // LI, Version, Mode packetbuffer[1] = 0; // Stratum, or type of clock packetbuffer[2] = 6; // Polling Interval packetbuffer[3] = 0xEC; // Peer Clock Precision // 8 bytes of zero for Root Delay & Root Dispersion packetbuffer[12] = 49;

10 packetbuffer[13] = 0x4E; packetbuffer[14] = 49; packetbuffer[15] = 52; // all NTP fields have been given values, now // you can send a packet requesting a timestamp: Udp.beginPacket(address, 123); //NTP requests are to port 123 Udp.write(packetBuffer, NTP_PACKET_SIZE); Udp.endPacket(); String print2digits(int number) { String ttt ; if (number >= 0 && number < 10) { ttt =String("0")+String(number); else { ttt =String(number); return ttt ; String print4digits(int number) { String ttt ; ttt =String(number); return ttt ; 下載網址 : 如下圖所示, 讀者可以看到本次實驗 - 網路校時測試程式結果畫 面

11 圖 6 網路校時測試程式結果畫面 透過網路校時設計 RTC 時鐘模組 整合上述程式, 我們可以將 RTC 時鐘模組的網路校時功能給予實 作出來 我們打開 Arduino 開發板的開發工具 :Sketch IDE 整合開發軟 體, 攥寫一段程式, 如下表所示之網路校時 RTC 時鐘模組測試程式, 我們就可以透過 W5100 以太網路模組取得網路時間並校正 TC 時鐘模 組 表 2 網路校時 RTC 時鐘模組測試程式 網路校時 RTC 時鐘模組測試程式 (SetTime_fromNet) #include <Time.h> #include <DS1307RTC.h> #include <SPI.h>

12 #include <Ethernet.h> #include <EthernetUdp.h> tmelements_t tm; int Ntpyr,Ntpmon,Ntpday,Ntphr,Ntpmin,Ntpsec ; // Enter a MAC address for your controller below. // Newer Ethernet shields have a MAC address printed on a sticker on the shield byte mac[] = { 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF ; IPAddress ip(192, 168, 2, 200); //fix ip IPAddress dnserver(168, 95, 1, 1); //dns ip // the router's gateway address: IPAddress gateway(192, 168, 2, 254); //gateway ip // the subnet: IPAddress subnet(255, 255, 255, 0); //sub mask unsigned int localport = 8888; packets // local port to listen for UDP char timeserver[] = "time.nist.gov"; // time.nist.gov NTP server const int NTP_PACKET_SIZE = 48; // NTP time stamp is in the first 48 bytes of the message byte packetbuffer[ NTP_PACKET_SIZE]; //buffer to hold incoming and outgoing packets // A UDP instance to let us send and receive packets over UDP EthernetUDP Udp; // timezoneoffset = (Time Zone) * 3600L eg. (+8) * 3600L = 28800L for Taipei, Taiwan const long timezoneoffset = 28800L;

13 // sync to NTP server every "ntpsynctime" seconds, set to 1 hour or more to be reasonable unsigned long ntpsynctime = 21600; // adjust the sync latency with computer NTP client in seconds unsigned int synclatency = 2; const char *monthname[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" ; void setup() { Serial.begin(9600); while (!Serial) { ; // wait for serial port to connect. Needed for Leonardo only if (Ethernet.begin(mac) == 0) { Serial.println("Failed to configure Ethernet using DHCP"); // no point in carrying on, so do nothing forevermore: Ethernet.begin(mac, ip, dnserver, gateway, subnet); Udp.begin(localPort); Serial.begin(9600); ntpsyncds1307() ; void loop() { tmelements_t ttm; if (RTC.read(ttm)) { Serial.print("Ok, Time = ");

14 Serial.print(print2digits(ttm.Hour)); Serial.print(':'); Serial.print(print2digits(ttm.Minute)); Serial.print(':'); Serial.print(print2digits(ttm.Second)); Serial.print(", Date (Y/M/D) = "); Serial.print(print4digits(tmYearToCalendar(ttm.Year))); Serial.print('/'); Serial.print(print2digits(ttm.Month)); Serial.print('/'); Serial.print(print2digits(ttm.Day)); Serial.println(); else { if (RTC.chipPresent()) { Serial.println("The DS1307 is stopped. Please run the Set-Time"); Serial.println("example to initialize the time and begin run-ning."); Serial.println(); else { Serial.println("DS1307 read error! Please check the cir-cuitry."); Serial.println(); delay(9000); delay(1000); // send an NTP request to the time server at the given address unsigned long sendntppacket(char* address) { // set all bytes in the buffer to 0 memset(packetbuffer, 0, NTP_PACKET_SIZE); // Initialize values needed to form NTP request // (see URL above for details on the packets) packetbuffer[0] = 0b ; // LI, Version, Mode packetbuffer[1] = 0; // Stratum, or type of clock

15 packetbuffer[2] = 6; // Polling Interval packetbuffer[3] = 0xEC; // Peer Clock Precision // 8 bytes of zero for Root Delay & Root Dispersion packetbuffer[12] = 49; packetbuffer[13] = 0x4E; packetbuffer[14] = 49; packetbuffer[15] = 52; // all NTP fields have been given values, now // you can send a packet requesting a timestamp: Udp.beginPacket(address, 123); //NTP requests are to port 123 Udp.write(packetBuffer, NTP_PACKET_SIZE); Udp.endPacket(); String print2digits(int number) { String ttt ; if (number >= 0 && number < 10) { ttt =String("0")+String(number); else { ttt =String(number); return ttt ; String print4digits(int number) { String ttt ; ttt =String(number); return ttt ; void getinternetdatetime() { sendntppacket(timeserver); // send an NTP packet to a time server

16 // wait to see if a reply is available delay(1000); if ( Udp.parsePacket() ) { // We've received a packet, read the data from it Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer bytes, //the timestamp starts at byte 40 of the received packet and is four // or two words, long. First, esxtract the two words: unsigned long highword = word(packetbuffer[40], packetbuffer[41]); unsigned long lowword = word(packetbuffer[42], packetbuffer[43]); // combine the four bytes (two words) into a long integer // this is NTP time (seconds since Jan ): unsigned long secssince1900 = highword << 16 lowword; Serial.print("Seconds since Jan = " ); Serial.println(secsSince1900); // now convert NTP time into everyday time: Serial.print("Unix time = "); // Unix time starts on Jan In seconds, that's : const unsigned long seventyyears = UL; // subtract seventy years: unsigned long epoch = secssince seventyyears; // print Unix time: Serial.println(epoch); // print the hour, minute and second: Serial.print("The UTC time is "); // UTC is the time at Greenwich Meridian (GMT) Serial.print((epoch % 86400L) / 3600); // print the hour (86400 equals secs per day) Serial.print(':'); if ( ((epoch % 3600) / 60) < 10 ) { // In the first 10 minutes of each hour, we'll want a leading '0'

17 Serial.print('0'); Serial.print((epoch % 3600) / 60); // print the minute (3600 equals secs per minute) Serial.print(':'); if ( (epoch % 60) < 10 ) { // In the first 10 seconds of each minute, we'll want a leading '0' Serial.print('0'); Serial.println(epoch % 60); // print the second // wait ten seconds before asking for the time again // functions to be called when an alarm triggers: void ntpsyncds1307() { sendntppacket(timeserver); // send an NTP packet to a time server // wait to see if a replay is available delay(1000); if (Udp.parsePacket()) { // We've received a packet, read the data from it Udp.read(packetBuffer, NTP_PACKET_SIZE); // read the packet into the buffer // the timstamp starts at byte 40 of the received packet and is four bytes, // or two words, long. First, extract the two words: unsigned long highword = word(packetbuffer[40], packetbuffer[41]); unsigned long lowword = word(packetbuffer[42], packetbuffer[43]); // combine the four bytes (two words) into a long integer // this is NTP time (seconds since Jan ) unsigned long secssince1900 = highword << 16 lowword; // now convert NTP time into everyday time: // Unix time starts on Jan In seconds, that's : const unsigned long seventyyears = L; // substract seventy years: unsigned long epoch = secssince seventyyears + timezoneoffset

18 + synclatency; settime(epoch); RTC.set(epoch); // RTC.Write // output time and "Sync OK" message every sync Serial.print(year()); Serial.print('-'); Serial.print(month()); Serial.print('-'); Serial.print(day()); Serial.print(' '); Serial.print(hour()); Serial.print(':'); Serial.print(minute()); Serial.print(':'); Serial.print(second()); Serial.print(' '); Serial.println("Sync OK"); 下載網址 : 如下圖所示, 讀者可以看到本次實驗 - 網路校時 RTC 時鐘模組測 試程式結果畫面

19 圖 7 網路校時 RTC 時鐘模組測試程式結果畫面 本文主要介紹之 Arduino 開發板, 透過 W5100 乙太網路擴充卡連接上網際網路, 取得網路校正時間, 並且成功校正 RTC 時鐘模組, 這樣的功能, 非常的網路化 實務化的核心功能 透過本文的解說, 相信讀者更可以應用 RTC 時鐘模組到商業化的產品, 進而將本技術應用在物聯網的核心技術, 後續筆者還會繼續發表智慧家庭相關的文章, 讓我們在未來可以創造出更優質 智慧化的家庭 敬請期待更多的文章

20 筆者介紹曹永忠 (Yung-Chung Tsao): 目前為自由作家, 專注於軟體工程 軟體開發與設計 物件導向程式設計 Arduino 開發 嵌入式系統開發, 商品攝影及人像攝影 長期投入資訊系統設計與開發 企業應用系統開發 軟體工程 新產品開發管理 商品及人像攝影等領域, 並持續發表作品及相關專業著作 ID:dr.brucetsao Arduino 部落格 : 臉書社群 (Arduino.Taiwan): 活動官網 : Youtube: 參考文獻 : 曹永忠, 許智誠, & 蔡英德. (2015a). Arduino 投币定时器 ( 网络篇 ):Using Arduino to Develop a Timing Controlling Device via Internet ( 初版 ed.). 台湾 彰化 : 渥瑪數位有限公司. 曹永忠, 許智誠, & 蔡英德. (2015b). Arduino 投幣計時器 ( 網路篇 ):Using Arduino to Develop a Timing Controlling Device via Internet ( 初版 ed.). 台湾 彰化 : 渥瑪數位有限公司. 曹永忠, 許智誠, & 蔡英德. (2015c). Arduino 程式教學 ( 常用模組篇 ):Arduino Programming (37 Sensor Modules) ( 初版 ed.). 台湾 彰化 : 渥玛数位有限公司. 曹永忠, 許智誠, & 蔡英德. (2015d). Arduino 程式教學 ( 無線通訊篇 ):Arduino Programming (Wireless Communication) ( 初版 ed.). 台湾 彰化 : 渥瑪數位有限公司. 曹永忠, 許智誠, & 蔡英德. (2015e). Arduino 编程教学 ( 无线通讯篇 ):Arduino Programming (Wireless Communication) ( 初版 ed.). 台湾 彰化 : 渥瑪數位有限公司. 曹永忠, 許智誠, & 蔡英德. (2015f). Arduino 编程教学 ( 常用模块篇 ):Arduino Programming (37 Sensor Modules) ( 初版 ed.). 台湾 彰化 : 渥玛数位有限公司. 曹永忠, 許碩芳, 許智誠, & 蔡英德. (2015a). Arduino 程式教學 (RFID 模組篇 ):Arduino Programming (RFID Sensors Kit) ( 初版 ed.). 台湾 彰化 : 渥瑪

21 數位有限公司. 曹永忠, 許碩芳, 許智誠, & 蔡英德. (2015b). Arduino 編程教学 (RFID 模块篇 ):Arduino Programming (RFID Sensors Kit) ( 初版 ed.). 台湾 彰化 : 渥瑪數位有限公司.