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https://e2e.ti.com/support/microcontrollers/msp-low-power-microcontrollers-group/msp430/f/msp-low-power-microcontroller-forum/1329533/msp430fr4133-msp430fr4133-i2c-help
大家好、我希望有人可以帮助我配置 MSP430Fr4133以便与 SSD1306 I2C 显示屏配合使用？
// I2C.c #include "i2c.h" #include <msp430fr4133.h> #include <stdint.h> #define SDA BIT2 // i2c sda P5.2 #define SCL BIT3 // i2c scl P5.3 unsigned char* PTxData; // Pointer to TX data unsigned char TxByteCtr; // number of bytes to TX void i2c_init(void) { P5SEL0 |= SCL + SDA; // Assign I2C pins to USCI_B0 UCB0CTL1 |= UCSWRST; // Enable SW reset UCB0CTLW0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode UCB0CTL1 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset UCB0BRW = 10; // fSCL = SMCLK/10 = ~100kHz with SMCLK 1MHz UCB0BRW = 0; UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation UCB0IE |= UCTXIE0; // Enable TX interrupt } // end i2c_init void i2c_write(unsigned char slave_address, unsigned char *DataBuffer, unsigned char ByteCtr) { UCB0I2CSA = slave_address; PTxData = DataBuffer; TxByteCtr = ByteCtr; while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent __bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts // Remain in LPM0 until all data is TX'd } #pragma vector = USCI_B0_VECTOR __interrupt void USCIB0_ISR(void){ switch(__even_in_range(UCB0IV,0x1E)) { case USCI_NONE: break; // Vector 0: No interrupts break; case USCI_I2C_UCALIFG: break; case USCI_I2C_UCNACKIFG: break; case USCI_I2C_UCSTTIFG: break; // Vector 6: STTIFG break; case USCI_I2C_UCSTPIFG: break; // Vector 8: STPIFG break; case USCI_I2C_UCRXIFG3: break; // Vector 10: RXIFG3 break; case USCI_I2C_UCTXIFG3: break; // Vector 14: TXIFG3 break; case USCI_I2C_UCRXIFG2: break; // Vector 16: RXIFG2 break; case USCI_I2C_UCTXIFG2: break; // Vector 18: TXIFG2 break; case USCI_I2C_UCRXIFG1: break; // Vector 20: RXIFG1 break; case USCI_I2C_UCTXIFG1: break; // Vector 22: TXIFG1 break; case USCI_I2C_UCRXIFG0: break; // Vector 24: RXIFG0 break; case USCI_I2C_UCTXIFG0: if (TxByteCtr) { // Check TX byte counter UCB0TXBUF = *PTxData++; // Load TX buffer TxByteCtr--; // Decrement TX byte counter } else { UCB0CTL1 |= UCTXSTP; // I2C stop condition UCB0IE &= ~UCTXIE0; // Clear USCI_B0 TX int flag __bic_SR_register_on_exit(CPUOFF);// Exit LPM0 } break; // Vector 26: TXIFG0 break; case USCI_I2C_UCBCNTIFG: break; // Vector 28: BCNTIFG case USCI_I2C_UCCLTOIFG: break; // Vector 30: clock low timeout case USCI_I2C_UCBIT9IFG: break; // Vector 32: 9th bit default: break; } } //I2C.h #ifndef I2C_H_ #define I2C_H_ #include <msp430fr4133.h> /* ==================================================================== * I2C Prototype Definitions * ==================================================================== */ void i2c_init(void); void i2c_write(unsigned char, unsigned char *, unsigned char); #endif /* I2C_H_ */ /* * ssd1306.h */ #ifndef SSD1306_H_ #define SSD1306_H_ #include <msp430fr4133.h> #include <stdint.h> #include <string.h> #include "i2c.h" /* ==================================================================== * Horizontal Centering Number Array * ==================================================================== */ #define HCENTERUL_OFF 0 #define HCENTERUL_ON 1 /* ==================================================================== * SSD1306 OLED Settings and Command Definitions * ==================================================================== */ #define SSD1306_I2C_ADDRESS 0x3C #define SSD1306_LCDWIDTH 128 #define SSD1306_LCDHEIGHT 64 #define SSD1306_128_64 #define SSD1306_SETCONTRAST 0x81 #define SSD1306_DISPLAYALLON_RESUME 0xA4 #define SSD1306_DISPLAYALLON 0xA5 #define SSD1306_NORMALDISPLAY 0xA6 #define SSD1306_INVERTDISPLAY 0xA7 #define SSD1306_DISPLAYOFF 0xAE #define SSD1306_DISPLAYON 0xAF #define SSD1306_SETDISPLAYOFFSET 0xD3 #define SSD1306_SETCOMPINS 0xDA #define SSD1306_SETVCOMDETECT 0xDB #define SSD1306_SETDISPLAYCLOCKDIV 0xD5 #define SSD1306_SETPRECHARGE 0xD9 #define SSD1306_SETMULTIPLEX 0xA8 #define SSD1306_SETLOWCOLUMN 0x00 #define SSD1306_SETHIGHCOLUMN 0x10 #define SSD1306_SETSTARTLINE 0x40 #define SSD1306_MEMORYMODE 0x20 #define SSD1306_COLUMNADDR 0x21 #define SSD1306_PAGEADDR 0x22 #define SSD1306_COMSCANINC 0xC0 #define SSD1306_COMSCANDEC 0xC8 #define SSD1306_SEGREMAP 0xA0 #define SSD1306_CHARGEPUMP 0x8D #define SSD1306_EXTERNALVCC 0x1 #define SSD1306_SWITCHCAPVCC 0x2 // currently no scroll functionality, left for possible future use #define SSD1306_ACTIVATE_SCROLL 0x2F #define SSD1306_DEACTIVATE_SCROLL 0x2E #define SSD1306_SET_VERTICAL_SCROLL_AREA 0xA3 #define SSD1306_RIGHT_HORIZONTAL_SCROLL 0x26 #define SSD1306_LEFT_HORIZONTAL_SCROLL 0x27 #define SSD1306_VERTICAL_AND_RIGHT_HORIZONTAL_SCROLL 0x29 #define SSD1306_VERTICAL_AND_LEFT_HORIZONTAL_SCROLL 0x2A /* ==================================================================== * SSD1306 OLED Prototype Definitions * ==================================================================== */ void ssd1306_init(void); void ssd1306_command(unsigned char); void ssd1306_clearDisplay(void); void ssd1306_setPosition(uint8_t, uint8_t); void ssd1306_printText(uint8_t, uint8_t, char *); void ssd1306_printTextBlock(uint8_t, uint8_t, char *); void ssd1306_printUI32(uint8_t, uint8_t, uint32_t, uint8_t); uint8_t digits(uint32_t); void ultoa(uint32_t, char *); void reverse(char *); #endif /* SSD1306_H_ */ /* * ssd1306.c */ #include "ssd1306.h" #include <msp430fr4133.h> #include <stdint.h> #include "font_5x7.h" #include "i2c.h" /* ==================================================================== * Horizontal Centering Number Array * ==================================================================== */ unsigned char buffer[17]; // buffer for data transmission to screen const unsigned char HcenterUL[] = { // Horizontally center number with separators on screen 0, // 0 digits, not used but included to size array correctly 61, // 1 digit 58, // 2 digits 55, // 3 digits 49, // 4 digits and 1 separator 46, // 5 digits and 1 separator 43, // 6 digits and 1 separator 37, // 7 digits and 2 separators 34, // 8 digits and 2 separators 31, // 9 digits and 2 separators 25 // 10 digits and 3 separators }; void ssd1306_init(void) { // SSD1306 init sequence ssd1306_command(SSD1306_DISPLAYOFF); // 0xAE ssd1306_command(SSD1306_SETDISPLAYCLOCKDIV); // 0xD5 ssd1306_command(0x80); // the suggested ratio 0x80 ssd1306_command(SSD1306_SETMULTIPLEX); // 0xA8 ssd1306_command(SSD1306_LCDHEIGHT - 1); ssd1306_command(SSD1306_SETDISPLAYOFFSET); // 0xD3 ssd1306_command(0x0); // no offset ssd1306_command(SSD1306_SETSTARTLINE | 0x0); // line #0 ssd1306_command(SSD1306_CHARGEPUMP); // 0x8D ssd1306_command(0x14); // generate high voltage from 3.3v line internally ssd1306_command(SSD1306_MEMORYMODE); // 0x20 ssd1306_command(0x00); // 0x0 act like ks0108 ssd1306_command(SSD1306_SEGREMAP | 0x1); ssd1306_command(SSD1306_COMSCANDEC); ssd1306_command(SSD1306_SETCOMPINS); // 0xDA ssd1306_command(0x12); ssd1306_command(SSD1306_SETCONTRAST); // 0x81 ssd1306_command(0xCF); ssd1306_command(SSD1306_SETPRECHARGE); // 0xd9 ssd1306_command(0xF1); ssd1306_command(SSD1306_SETVCOMDETECT); // 0xDB ssd1306_command(0x40); ssd1306_command(SSD1306_DISPLAYALLON_RESUME); // 0xA4 ssd1306_command(SSD1306_NORMALDISPLAY); // 0xA6 ssd1306_command(SSD1306_DEACTIVATE_SCROLL); ssd1306_command(SSD1306_DISPLAYON); //--turn on oled panel } // end ssd1306_init void ssd1306_command(unsigned char command) { buffer[0] = 0x80; buffer[1] = command; i2c_write(SSD1306_I2C_ADDRESS, buffer, 2); } // end ssd1306_command void ssd1306_clearDisplay(void) { ssd1306_setPosition(0, 0); uint8_t i; for (i = 64; i > 0; i--) { // count down for loops when possible for ULP uint8_t x; for(x = 16; x > 0; x--) { if (x == 1) { buffer[x-1] = 0x40; } else { buffer[x-1] = 0x0; } } i2c_write(SSD1306_I2C_ADDRESS, buffer, 17); } } // end ssd1306_clearDisplay void ssd1306_setPosition(uint8_t column, uint8_t page) { if (column > 128) { column = 0; // constrain column to upper limit } if (page > 8) { page = 0; // constrain page to upper limit } ssd1306_command(SSD1306_COLUMNADDR); ssd1306_command(column); // Column start address (0 = reset) ssd1306_command(SSD1306_LCDWIDTH-1); // Column end address (127 = reset) ssd1306_command(SSD1306_PAGEADDR); ssd1306_command(page); // Page start address (0 = reset) ssd1306_command(7); // Page end address } // end ssd1306_setPosition void ssd1306_printText(uint8_t x, uint8_t y, char *ptString) { ssd1306_setPosition(x, y); while (*ptString != '\0') { buffer[0] = 0x40; if ((x + 5) >= 127) { // char will run off screen x = 0; // set column to 0 y++; // jump to next page ssd1306_setPosition(x, y); // send position change to oled } uint8_t i; for(i = 0; i< 5; i++) { buffer[i+1] = font_5x7[*ptString - ' '][i]; } buffer[6] = 0x0; i2c_write(SSD1306_I2C_ADDRESS, buffer, 7); ptString++; x+=6; } } // end ssd1306_printText void ssd1306_printTextBlock(uint8_t x, uint8_t y, char *ptString) { char word[12]; uint8_t i; uint8_t endX = x; while (*ptString != '\0'){ i = 0; while ((*ptString != ' ') && (*ptString != '\0')) { word[i] = *ptString; ptString++; i++; endX += 6; } word[i++] = '\0'; if (endX >= 127) { x = 0; y++; ssd1306_printText(x, y, word); endX = (i * 6); x = endX; } else { ssd1306_printText(x, y, word); endX += 6; x = endX; } ptString++; } } void ssd1306_printUI32( uint8_t x, uint8_t y, uint32_t val, uint8_t Hcenter ) { char text[14]; ultoa(val, text); if (Hcenter) { ssd1306_printText(HcenterUL[digits(val)], y, text); } else { ssd1306_printText(x, y, text); } } // end ssd1306_printUI32 uint8_t digits(uint32_t n) { if (n < 10) { return 1; } else if (n < 100) { return 2; } else if (n < 1000) { return 3; } else if (n < 10000) { return 4; } else if (n < 100000) { return 5; } else if (n < 1000000) { return 6; } else if (n < 10000000) { return 7; } else if (n < 100000000) { return 8; } else if (n < 1000000000) { return 9; } else { return 10; } } // end digits void ultoa(uint32_t val, char *string) { uint8_t i = 0; uint8_t j = 0; // use do loop to convert val to string do { if (j==3) { // we have reached a separator position string[i++] = ','; // add a separator to the number string j=0; // reset separator indexer thingy } string[i++] = val%10 + '0'; // add the ith digit to the number string j++; // increment counter to keep track of separator placement } while ((val/=10) > 0); string[i++] = '\0'; // add termination to string reverse(string); // string was built in reverse, fix that } // end ultoa void reverse(char *s) { uint8_t i, j; uint8_t c; for (i = 0, j = strlen(s)-1; i<j; i++, j--) { c = s[i]; s[i] = s[j]; s[j] = c; } } // end reverse /* * font_5x7.h */ #ifndef FONT_5X7_H_ #define FONT_5X7_H_ const unsigned char font_5x7[96][5] = {{0x00, 0x00, 0x00, 0x00, 0x00}, // space {0x00, 0x00, 0x4F, 0x00, 0x00}, // ! {0x00, 0x07, 0x00, 0x07, 0x00}, // " {0x14, 0x7F, 0x14, 0x7F, 0x14}, // # {0x24, 0x2A, 0x7F, 0x2A, 0x12}, // $ {0x23, 0x13, 0x08, 0x64, 0x62}, // % {0x36, 0x49, 0x55, 0x22, 0x50}, // & {0x00, 0x05, 0x03, 0x00, 0x00}, // ' {0x00, 0x1C, 0x22, 0x41, 0x00}, // ( {0x00, 0x41, 0x22, 0x1C, 0x00}, // ) {0x14, 0x08, 0x3E, 0x08, 0x14}, // * {0x08, 0x08, 0x3E, 0x08, 0x08}, // + {0x00, 0x50, 0x30, 0x00, 0x00}, // , {0x08, 0x08, 0x08, 0x08, 0x08}, // - {0x00, 0x60, 0x60, 0x00, 0x00}, // . {0x20, 0x10, 0x08, 0x04, 0x02}, // / {0x3E, 0x51, 0x49, 0x45, 0x3E}, // 0 {0x00, 0x42, 0x7F, 0x40, 0x00}, // 1 {0x42, 0x61, 0x51, 0x49, 0x46}, // 2 {0x21, 0x41, 0x45, 0x4B, 0x31}, // 3 {0x18, 0x14, 0x12, 0x7F, 0x10}, // 4 {0x27, 0x49, 0x49, 0x49, 0x31}, // 5 {0x3C, 0x4A, 0x49, 0x49, 0x30}, // 6 {0x01, 0x71, 0x09, 0x05, 0x03}, // 7 {0x36, 0x49, 0x49, 0x49, 0x36}, // 8 {0x06, 0x49, 0x49, 0x29, 0x1E}, // 9 {0x00, 0x36, 0x36, 0x00, 0x00}, // : {0x00, 0x56, 0x36, 0x00, 0x00}, // ; {0x08, 0x14, 0x22, 0x41, 0x00}, // < {0x14, 0x14, 0x14, 0x14, 0x14}, // = {0x00, 0x41, 0x22, 0x14, 0x08}, // > {0x02, 0x01, 0x51, 0x09, 0x06}, // ? {0x32, 0x49, 0x79, 0x41, 0x3E}, // @ {0x7E, 0x11, 0x11, 0x11, 0x7E}, // A {0x7F, 0x49, 0x49, 0x49, 0x36}, // B {0x3E, 0x41, 0x41, 0x41, 0x22}, // C {0x7F, 0x41, 0x41, 0x22, 0x1C}, // D {0x7F, 0x49, 0x49, 0x49, 0x41}, // E {0x7F, 0x09, 0x09, 0x09, 0x01}, // F {0x3E, 0x41, 0x49, 0x49, 0x7A}, // G {0x7F, 0x08, 0x08, 0x08, 0x7F}, // H {0x00, 0x41, 0x7F, 0x41, 0x00}, // I {0x20, 0x40, 0x41, 0x3F, 0x01}, // J {0x7F, 0x08, 0x14, 0x22, 0x41}, // K {0x7F, 0x40, 0x40, 0x40, 0x40}, // L {0x7F, 0x02, 0x0C, 0x02, 0x7F}, // M {0x7F, 0x04, 0x08, 0x10, 0x7F}, // N {0x3E, 0x41, 0x41, 0x41, 0x3E}, // O {0x7F, 0x09, 0x09, 0x09, 0x06}, // P {0x3E, 0x41, 0x51, 0x21, 0x5E}, // Q {0x7F, 0x09, 0x19, 0x29, 0x46}, // R {0x46, 0x49, 0x49, 0x49, 0x31}, // S {0x01, 0x01, 0x7F, 0x01, 0x01}, // T {0x3F, 0x40, 0x40, 0x40, 0x3F}, // U {0x1F, 0x20, 0x40, 0x20, 0x1F}, // V {0x3F, 0x40, 0x38, 0x40, 0x3F}, // W {0x63, 0x14, 0x08, 0x14, 0x63}, // X {0x07, 0x08, 0x70, 0x08, 0x07}, // Y {0x61, 0x51, 0x49, 0x45, 0x43}, // Z {0x7F, 0x41, 0x41, 0x00, 0x00}, // [ {0x02, 0x04, 0x08, 0x10, 0x20}, // forward slash {0x00, 0x41, 0x41, 0x7F, 0x00}, // ] {0x04, 0x02, 0x01, 0x02, 0x04}, // ^ {0x40, 0x40, 0x40, 0x40, 0x40}, // _ {0x00, 0x01, 0x02, 0x04, 0x00}, // ` {0x20, 0x54, 0x54, 0x54, 0x78}, // a {0x7F, 0x48, 0x44, 0x44, 0x38}, // b {0x38, 0x44, 0x44, 0x44, 0x20}, // c {0x38, 0x44, 0x44, 0x48, 0x7F}, // d {0x38, 0x54, 0x54, 0x54, 0x18}, // e {0x08, 0x7E, 0x09, 0x01, 0x02}, // f {0x0C, 0x52, 0x52, 0x52, 0x3E}, // g {0x7F, 0x08, 0x04, 0x04, 0x78}, // h {0x00, 0x44, 0x7D, 0x40, 0x00}, // i {0x20, 0x40, 0x44, 0x3D, 0x00}, // j {0x7F, 0x10, 0x28, 0x44, 0x00}, // k {0x00, 0x41, 0x7F, 0x40, 0x00}, // l {0x7C, 0x04, 0x18, 0x04, 0x78}, // m {0x7C, 0x08, 0x04, 0x04, 0x78}, // n {0x38, 0x44, 0x44, 0x44, 0x38}, // o {0x7C, 0x14, 0x14, 0x14, 0x08}, // p {0x08, 0x14, 0x14, 0x18, 0x7C}, // q {0x7C, 0x08, 0x04, 0x04, 0x08}, // r {0x48, 0x54, 0x54, 0x54, 0x20}, // s {0x04, 0x3F, 0x44, 0x40, 0x20}, // t {0x3C, 0x40, 0x40, 0x20, 0x7C}, // u {0x1C, 0x20, 0x40, 0x20, 0x1C}, // v {0x3C, 0x40, 0x30, 0x40, 0x3C}, // w {0x44, 0x28, 0x10, 0x28, 0x44}, // x {0x0C, 0x50, 0x50, 0x50, 0x3C}, // y {0x44, 0x64, 0x54, 0x4C, 0x44}, // z }; #endif /* FONT_5X7_H_ */ #include <msp430fr4133.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include "SSD1306.h" #include "i2c.h" #define ANUMBER 19052019 #define MAX_COUNT 4.2e9 #define LONG_DELAY __delay_cycles(3000000) #define SHORT_DELAY __delay_cycles(50000) int main(void) { WDTCTL = WDTPW | WDTHOLD; // stop watchdog timer i2c_init(); // initialize I2C to use with OLED ssd1306_init(); // Initialize SSD1306 OLED ssd1306_clearDisplay(); // Clear OLED display __enable_interrupt(); PMM_unlockLPM5(); while(1) { // ========================================= // Display a Long Text Block // ========================================= // There seems to be a bug in the ssd1306_printTextBlock code, // long text blocks like below need 1 extra character in their array // so the code does not read outside of the array. The below 91 character // text block should only need a array of 92 but to fix the bug use an array of 93. // !!!! MUST FIX BUG IN THE FUTURE !!!! char txtBlock[93] = "This is a long multiline text block. The code will automatically add extra lines as needed."; ssd1306_printTextBlock(0, 1, txtBlock); LONG_DELAY; // Avoid delay loops in real code, use timer ssd1306_clearDisplay(); // ========================================= // Print Single Lines of Text at each row // ========================================= ssd1306_printText(0, 1, "Line 1"); ssd1306_printText(0, 2, "Line 2"); ssd1306_printText(0, 3, "Line 3"); ssd1306_printText(0, 4, "Line 4"); ssd1306_printText(0, 5, "Line 5"); ssd1306_printText(0, 6, "Line 6"); ssd1306_printText(0, 7, "Line 7"); // Print these at a column other then zero ssd1306_printText(40, 1, "40"); ssd1306_printText(50, 2, "50"); ssd1306_printText(60, 3, "60"); ssd1306_printText(70, 4, "70"); ssd1306_printText(80, 5, "80"); ssd1306_printText(90, 6, "90"); ssd1306_printText(100, 7, "100"); // Hold screen for some time before displaying the next sample LONG_DELAY; // Avoid delay loops in real code, use timer ssd1306_clearDisplay(); // ========================================= // Print Unsigned 32 bit number // ========================================= ssd1306_printUI32(0, 1, ANUMBER, HCENTERUL_OFF); // Print number on line 1 ssd1306_printUI32(0, 2, ANUMBER, HCENTERUL_ON); // Print number on line 2, horizontally centered // Print counting on line 6 horizontally centered uint32_t i = 1; uint32_t j; uint32_t val = 0; while (i<1e9) { for(j=0; j<10; j++) { val = i * j; ssd1306_printUI32(0, 6 , val, HCENTERUL_ON); SHORT_DELAY; } i *= 10; } for (j=0; j<5; j++) { val = i * j; ssd1306_printUI32(0, 6 , val, HCENTERUL_ON); SHORT_DELAY; } LONG_DELAY; ssd1306_clearDisplay(); } }
它在您运行时有什么作用？
----------------
> PMM_unlockLPM5 ()；
将其上移、使其在调用 ssd1306 _init (或甚至在 i2c_init 之前)之前、因为它需要运行 GPIO。
我还建议您检查 NACK (UCNACKIE/USCI_I2C_UCNACKIFG)、以防万一。
[编辑:更正了拼写错误。]
您好、Bruce、感谢您的回复。 我已经纳入了你的建议,但仍然没有运气。 屏幕不显示任何内容。 从进行一些调试(在中断矢量处设置断点)、代码似乎从不 进入中断例程。 我已根据使用 I2C 的 MSP Academy 示例修改了寄存器、并获得以下代码。 不过、屏幕上仍然没有输出。 感谢您尝试解决此问题。
#include "i2c.h" #include <msp430fr4133.h> #include <stdint.h> #define SDA BIT2 // i2c sda P5.2 #define SCL BIT3 // i2c scl P5.3 unsigned char *PTxData; // Pointer to TX data unsigned char TxByteCtr; // number of bytes to TX void i2c_init(void) { P5SEL0 |= SCL + SDA; // Assign I2C pins to USCI_B0 UCB0CTLW0 |= UCSWRST; // Enable SW reset UCB0CTLW0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode UCB0CTLW0 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset UCB0BRW = 10; // fSCL = SMCLK/10 = ~100kHz with SMCLK 1MHz UCB0BRW = 0; UCB0CTLW0 &= ~UCSWRST; // Clear SW reset, resume operation UCB0IE |= UCTXIE0 | UCNACKIE; // Enable TX interrupt } // end i2c_init void i2c_write(unsigned char slave_address, unsigned char *DataBuffer, unsigned char ByteCtr) { UCB0I2CSA = slave_address; PTxData = DataBuffer; TxByteCtr = ByteCtr; while (UCB0CTLW0 & UCTXSTP); // Ensure stop condition got sent UCB0CTLW0 |= UCTR + UCTXSTT; // I2C TX, start condition while (UCB0CTLW0 & UCTXSTP); // Ensure stop condition got sent // Remain in LPM0 until all data is TX'd } #pragma vector = USCI_B0_VECTOR __interrupt void USCIB0_ISR(void){ switch(__even_in_range(UCB0IV,0x1E)) { case USCI_NONE: break; // Vector 0: No interrupts break; case USCI_I2C_UCALIFG: break; case USCI_I2C_UCNACKIFG: // do something break; case USCI_I2C_UCSTTIFG: break; // Vector 6: STTIFG break; case USCI_I2C_UCSTPIFG: break; // Vector 8: STPIFG break; case USCI_I2C_UCRXIFG3: break; // Vector 10: RXIFG3 break; case USCI_I2C_UCTXIFG3: break; // Vector 14: TXIFG3 break; case USCI_I2C_UCRXIFG2: break; // Vector 16: RXIFG2 break; case USCI_I2C_UCTXIFG2: break; // Vector 18: TXIFG2 break; case USCI_I2C_UCRXIFG1: break; // Vector 20: RXIFG1 break; case USCI_I2C_UCTXIFG1: break; // Vector 22: TXIFG1 break; case USCI_I2C_UCRXIFG0: break; // Vector 24: RXIFG0 break; case USCI_I2C_UCTXIFG0: if (TxByteCtr) { // Check TX byte counter UCB0TXBUF = *PTxData++; // Load TX buffer TxByteCtr--; // Decrement TX byte counter } else { UCB0CTLW0 |= UCTXSTP; // I2C stop condition UCB0IFG &= ~UCTXIFG; } break; // Vector 26: TXIFG0 break; case USCI_I2C_UCBCNTIFG: break; // Vector 28: BCNTIFG case USCI_I2C_UCCLTOIFG: break; // Vector 30: clock low timeout case USCI_I2C_UCBIT9IFG: break; // Vector 32: 9th bit default: break; } } // main.c, prior to while loop WDTCTL = WDTPW | WDTHOLD; // stop watchdog timer PMM_unlockLPM5(); __enable_interrupt(); i2c_init(); // initialize I2C to use with OLED ssd1306_init(); // Initialize SSD1306 OLED ssd1306_clearDisplay(); // Clear OLED display
这有问题：
UCB0CTLW0 |= UCSWRST; // Enable SW reset UCB0CTLW0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode UCB0CTLW0 = UCSSEL_2 + UCSWRST;
至少可以将它从混合字和字节访问的第一个版本更改为更糟糕的版本。
行2清零 UCSWRST、行3清零行2中所做的设置。
它应该与以下代码类似：
UCB0CTLW0 = UCSWRST; // Enable SW reset UCB0CTLW0 |= UCMST | UCMODE_3 | UCSYNC | UCSSEL_2; // I2C Master, synchronous mode
谢谢、David。 出于某些原因、只有当我在宏之间使用"+"符号而不是"|"符号时、代码才会进入 ISR。 此代码现在触发 ISR：
void i2c_init (void)｛
P5SEL0 |= SCL；//将 I2C 引脚分配至 USCI_B0
P5SEL0 |= SDA；
UCB0CTLW0 |= UCSWRST；//启用软件复位
UCB0CTLW0 |= UCMST + UCMODE_3 + UCSYNC；// I2C 主器件、同步模式
UCB0CTLW0 |= UCSSEL_2 + UCSWRST；//使用 SMCLK，保持软件复位
UCB0BRW = 10；// fSCL = SMCLK/10 =~100kHz 及 SMCLK 1MHz
UCB0BRW = 0；
UCB0CTLW0 &=~μ A UCSWRST；//清除软件复位、恢复操作
UCB0IE |= UCTXIE0；//启用 TX 中断
}//结束 i2c_init
但使用 UCB0CTLW0 |= UCSSEL_2 | UCSWRST 将不起作用。 屏幕上仍然没有输出、但这是一个进步。 您能否说明什么时候使用字节/字访问更好？ 我曾查看过相关的用户指南、但并未真正按照其中的说明操作。 感谢您的帮助
字节访问是从真正旧的 MSP430器件进行的保留、而旧的 MSP430器件也是如此。 TI 为那些从那里开始并倾向于该方式的符号提供了帮助。 我不喜欢它、因为当我看到 UCB0CTL1时、我认为高字节实际上是低字节。 太令人困惑了。 它是一个字寄存器使用字访问。
设置比特率的代码使用字访问、但在写入时假定有两个字节访问。 你不仅得到太快的比特率,但你违反了 brclk/4限制。
由于这些寄存器中的所有字段不重叠、因此 按位或与加法之间的结果不应有差异。 我更喜欢使用位元或、因为我真的不想在位之间进行进位。 即使是在偶然情况下。
另一个问题是、寄存器在复位后并不总是为零。 (请参阅文档。) 例如、UCCSEL 为3。 这一次不是问题。
非常感谢详细的答复,大卫。 我将在船上提供许多有用的信息、试着让它正常工作。 加油打气
您已删除 i2c_write 最后一行中的"_ bis_SR_register (CPUOFF + GIE)；"。 这是维护调度的内容。 现在一样、代码将循环运行、并在前一个操作完成前尝试开始一个新操作。 我建议您将这条线放回。
感谢 Bruce 的检查和建议。
尊敬的 Ross：
如果仍存在问题、请分享您正在使用的新代码。
同时、我还有进一步的调试建议-请检查 IIC 总线中的信号波形、当 没有数据或 时钟/数据不正确时。
B.R.
萨尔
感谢 Bruce 和 Sal 的支持。 我认为可能需要将 UCTXIE0更改为 UCTXIE2、因为原始库(为不同的 MSP 器件编写、使用的是 IE2 |= UCB0TXIE 行)。 显然、我的器件上没有 IE2寄存器、因此这可能是问题的根源。 我明天会用示波器尝试你的建议、Sal。 再次感谢你们
UCTXIFG2 (UCTXIE2)只在使用多个地址的从器件上触发(特别是 UCB0I2COA2)、但情况并非如此。 UCTXIE 与 UCTXIE0相同。
[编辑:次要澄清。]
谢谢 Bruce。 节省了几个小时！
大卫已经指出了这一点:
> UCB0BRW = 10；// fSCL = SMCLK/10 =~100kHz 及 SMCLK 1MHz
> UCB0BRW = 0；
您应该删除第二行、它(重新)将 I2C 时钟设置为1MHz。
