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【LinkIt 7687试用体验】SNTP時鐘(I)

2017-1-8 17:36:10 2792

0 <前言> 繼上一篇測試後,我們開始我們的開發,本開發設計基於MTK的Tutorial加以修改而成,但因為手邊並沒有Seeed所提供的LCD1602,所以必須自己根據範例原始碼來進行修改和移植,本篇著重在LCD1602-I2C介面的驅動修改和移植,下篇為驗證和增加整點報時 <準備> 1. 7687HDK開發板 2. MicroUSB傳輸線,有附 <實作> 1. 雖然Tutorial有提供完整的原始碼,但是為GCC環境編譯方式,而我是採用MDK-ARM,因此我們需要一個類似的範例來作修改,剛好在範例中找到SNTP的相關範例,要注意的是,所有APP範例中都是基於FreeRTOS的實時系統,這裡假設小伙伴們已經有些概念 4.1.0projectmt7687_hdkappssntp_client 复制代码 2. 打開MDK-ARM,並下載GCC範例的原始碼,https://github.com/MediaTek-Labs/linkit-7687-tutorial-digital-clock-part1,然後解壓縮,取出我們要的LCD驅動部分進行修改,檔案為lcd.c和lcd.h Fig.1 lcd.c檔所在位置,放置到4.1.0projectmt7687_hdkappssntp_clientsrc Fig.2 lcd.h檔所在位置,放置到4.1.0projectmt7687_hdkappssntp_clientinc 3. 在專案工程中增加一個Group,並命名為lcd,並加入剛剛獲取的原始碼檔lcd.c Fig.3 增加lcd.c原始碼檔 4. 開始修改原始碼,我的LCD1602-I2C模塊是Funduino出品,I2C晶片為PCF8574T,LCD晶片為HD44780,和官方所使用I2C晶片AIP31068L不同,因此我們必須修改成舊有的LCD1602-I2C驅動又能和7687HDK正確交互,所參考的舊版Arduino的Github原始碼出處 https://github.com/marcoschwartz/LiquidCrystal_I2C 5. 修改完成的lcd.c為以下 /* Kernel includes. / #include "FreeRTOS.h" #include "lcd.h" static uint8_t _displayfunction; static uint8_t _displaycontrol; static uint8_t _displaymode; static uint8_t _backlightval; static uint8_t _initialized; static uint8_t _numlines,_currline; static void (_write_func)(uint8_t addr, uint8_t* data, uint8_t dataLen); static void _i2c_send_byte(unsigned char data) { uint8_t d[1]; d[0] = data \| _backlightval; _write_func(LCD_ADDRESS, d, 1); } static void _i2c_send_byte2(unsigned char data1, unsigned char data2) { uint8_t d[2]; d[0] = data1; d[1] = data2; _write_func(LCD_ADDRESS, d, 2); } void rgblcd_registerFunc(void (i2cWrite)(uint8_t addr, uint8_t data, uint8_t dataLen)) { _write_func = i2cWrite; } void rgblcd_begin(uint8_t cols, uint8_t lines) { uint8_t dotsize = LCD_5x8DOTS; _backlightval = LCD_NOBACKLIGHT; _displayfunction=LCD_4BITMODE \| LCD_1LINE \| LCD_5x8DOTS; if (lines > 1) { _displayfunction \|= LCD_2LINE; } _numlines = lines; _currline = 0; // for some 1 line displays you can select a 10 pixel high font if ((dotsize != 0) && (lines == 1)) { _displayfunction \|= LCD_5x10DOTS; } // SEE PAGE 45/46 FOR INITIALIZATION SPECIFICATION! // according to datasheet, we need at least 40ms after power rises above 2.7V // before sending commands. Arduino can turn on way befer 4.5V so we'll wait 50 vTaskDelay(US2TICK(50000)); // this is according to the hitachi HD44780 datasheet // page 46 figure 24 // Send function set command sequence // we start in 8bit mode, try to set 4 bit mode write4bits(0x03 << 4); vTaskDelay(US2TICK(4500)); // wait min 4.1ms // second try write4bits(0x03 << 4); vTaskDelay(US2TICK(150)); // wait min 100us // third go! write4bits(0x03 << 4); // finally, set to 4-bit interface write4bits(0x02 << 4); //set # lines, font size, etc. rgblcd_command(LCD_FUNCTIONSET \| _displayfunction); // turn the display on with no cursor or blinking default _displaycontrol = LCD_DISPLAYON \| LCD_CURSOROFF \| LCD_BLINKOFF; rgblcd_display(); // clear it off rgblcd_clear(); // Initialize to default text direction (for romance languages) _displaymode = LCD_ENTRYLEFT \| LCD_ENTRYSHIFTDECREMENT; // set the entry mode rgblcd_command(LCD_ENTRYMODESET \| _displaymode); } /********** high level commands, for the user! / void rgblcd_clear() { rgblcd_command(LCD_CLEARDISPLAY); // clear display, set cursor position to zero vTaskDelay(US2TICK(2000)); // this command takes a long time! } void rgblcd_home() { rgblcd_command(LCD_RETURNHOME); // set cursor position to zero vTaskDelay(US2TICK(2000)); // this command takes a long time! } void rgblcd_setCursor(uint8_t col, uint8_t row) { int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 }; if ( row > _numlines ) { row = _numlines-1; // we count rows starting w/0 } rgblcd_command(LCD_SETDDRAMADDR \| (col + row_offsets[row])); } // Turn the display on/off (quickly) void rgblcd_noDisplay() { _displaycontrol &= ~LCD_DISPLAYON; rgblcd_command(LCD_DISPLAYCONTROL \| _displaycontrol); } void rgblcd_display() { _displaycontrol \|= LCD_DISPLAYON; rgblcd_command(LCD_DISPLAYCONTROL \| _displaycontrol); } // Turns the underline cursor on/off void rgblcd_noCursor() { _displaycontrol &= ~LCD_CURSORON; rgblcd_command(LCD_DISPLAYCONTROL \| _displaycontrol); } void rgblcd_cursor() { _displaycontrol \|= LCD_CURSORON; rgblcd_command(LCD_DISPLAYCONTROL \| _displaycontrol); } // Turn on and off the blinking cursor void rgblcd_noBlink() { _displaycontrol &= ~LCD_BLINKON; rgblcd_command(LCD_DISPLAYCONTROL \| _displaycontrol); } void rgblcd_blink() { _displaycontrol \|= LCD_BLINKON; rgblcd_command(LCD_DISPLAYCONTROL \| _displaycontrol); } // These commands scroll the display without changing the RAM void rgblcd_scrollDisplayLeft(void) { rgblcd_command(LCD_CURSORSHIFT \| LCD_DISPLAYMOVE \| LCD_MOVELEFT); } void rgblcd_scrollDisplayRight(void) { rgblcd_command(LCD_CURSORSHIFT \| LCD_DISPLAYMOVE \| LCD_MOVERIGHT); } // This is for text that flows Left to Right void rgblcd_leftToRight(void) { _displaymode \|= LCD_ENTRYLEFT; rgblcd_command(LCD_ENTRYMODESET \| _displaymode); } // This is for text that flows Right to Left void rgblcd_rightToLeft(void) { _displaymode &= ~LCD_ENTRYLEFT; rgblcd_command(LCD_ENTRYMODESET \| _displaymode); } // This will 'right justify' text from the cursor void rgblcd_autoscroll(void) { _displaymode \|= LCD_ENTRYSHIFTINCREMENT; rgblcd_command(LCD_ENTRYMODESET \| _displaymode); } // This will 'left justify' text from the cursor void rgblcd_noAutoscroll(void) { _displaymode &= ~LCD_ENTRYSHIFTINCREMENT; rgblcd_command(LCD_ENTRYMODESET \| _displaymode); } // Turn the (optional) backlight off/on void rgblcd_noBacklight(void) { _backlightval=LCD_NOBACKLIGHT; _i2c_send_byte(0); } void rgblcd_backlight(void) { _backlightval=LCD_BACKLIGHT; _i2c_send_byte(0); } /********** mid level commands, for sending data/cmds / // send command void rgblcd_command(uint8_t value) { uint8_t highnib=value&0xf0; uint8_t lownib=(value<<4)&0xf0; write4bits(highnib&~Rs); write4bits(lownib&~Rs); } // send data void rgblcd_write(uint8_t value) { uint8_t highnib=value&0xf0; uint8_t lownib=(value<<4)&0xf0; write4bits(highnib\|Rs); write4bits(lownib\|Rs); } void rgblcd_write_str(const char value) { while(value) { uint8_t highnib=(value)&0xf0; uint8_t lownib=((value)<<4)&0xf0; write4bits(highnib\|Rs); write4bits(lownib\|Rs); value++; } } void write4bits(uint8_t value) { _i2c_send_byte(value\|En); vTaskDelay(US2TICK(1)); _i2c_send_byte((value)&~En); vTaskDelay(US2TICK(50)); } 复制代码* 其中初始化LCD為4Bit輸入的指令序列,如HD44780 datasheet所表示 Fig.4 4Bit輸入模式初始化序列 Fig.5 各指令集修改的參考依據 Fig.6 各指令集修改的參考依據並使用FreeRTOS的延時函式,和SDK所提供HAL I2C的庫函式,整合在lcd.c中,其他程式碼涵義註解已經很清楚表達,然後我也將MTK原來的原始碼作調整,將define搬移至標頭檔,因此lcd.h如下 #include #include #include // Device I2C Arress #define LCD_ADDRESS (0x27) // commands #define LCD_CLEARDISPLAY 0x01 #define LCD_RETURNHOME 0x02 #define LCD_ENTRYMODESET 0x04 #define LCD_DISPLAYCONTROL 0x08 #define LCD_CURSORSHIFT 0x10 #define LCD_FUNCTIONSET 0x20 #define LCD_SETCGRAMADDR 0x40 #define LCD_SETDDRAMADDR 0x80 // flags for display entry mode #define LCD_ENTRYRIGHT 0x00 #define LCD_ENTRYLEFT 0x02 #define LCD_ENTRYSHIFTINCREMENT 0x01 #define LCD_ENTRYSHIFTDECREMENT 0x00 // flags for display on/off control #define LCD_DISPLAYON 0x04 #define LCD_DISPLAYOFF 0x00 #define LCD_CURSORON 0x02 #define LCD_CURSOROFF 0x00 #define LCD_BLINKON 0x01 #define LCD_BLINKOFF 0x00 // flags for display/cursor shift #define LCD_DISPLAYMOVE 0x08 #define LCD_CURSORMOVE 0x00 #define LCD_MOVERIGHT 0x04 #define LCD_MOVELEFT 0x00 // flags for function set #define LCD_8BITMODE 0x10 #define LCD_4BITMODE 0x00 #define LCD_2LINE 0x08 #define LCD_1LINE 0x00 #define LCD_5x10DOTS 0x04 #define LCD_5x8DOTS 0x00 // flags for backlight control #define LCD_BACKLIGHT 0x08 #define LCD_NOBACKLIGHT 0x00 #define En 0x04 // Enable bit #define Rw 0x02 // Read/Write bit #define Rs 0x01 // Register select bit #define US2TICK(us) (us/(1000portTICK_RATE_MS)) #define MS2TICK(ms) (ms/(portTICK_RATE_MS)) void rgblcd_registerFunc(void (i2cWrite)(uint8_t addr, uint8_t* data, uint8_t dataLen)); void rgblcd_begin(uint8_t cols, uint8_t lines); void rgblcd_clear(void); void rgblcd_home(void); void rgblcd_setCursor(uint8_t col, uint8_t row); void rgblcd_noDisplay(void); void rgblcd_display(void); void rgblcd_noCursor(void); void rgblcd_cursor(void); void rgblcd_noBlink(void); void rgblcd_blink(void); void rgblcd_scrollDisplayLeft(void); void rgblcd_scrollDisplayRight(void); void rgblcd_leftToRight(void); void rgblcd_rightToLeft(void); void rgblcd_autoscroll(void); void rgblcd_noAutoscroll(void); void rgblcd_command(uint8_t value); void rgblcd_write(uint8_t value); void rgblcd_write_str(const char value); void write4bits(uint8_t value); void rgblcd_noBacklight(void); void rgblcd_backlight(void); 复制代码* 以上就修改完成了,可以開始進行編譯 6. 在這裡還沒有和main進行交互,所以這裡只是修改成舊版本的PCF8574的功能,並編譯成功 Fig.7 編譯成功小結: 本篇主要說明I2C晶片組的不同而進行LCD1602的驅動修改,並能相容7687的HDK的HAL I2C函式庫,使用硬I2C進行通訊,下篇將說明如何整到main並增加整點鳴叫功能,需要對FreeRTOS有些基礎,可參考官網http://www.freertos.org/ 0
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