有關DS1821 sensor code problems |
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缺席
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specially527
一般會員   發表：2 回覆：2 積分：0 註冊：2012-10-02 發送簡訊給我 |
小弟最近在寫DS1821用於MSP430F449上的程式
對於下列程式碼的認知不是很清楚 懇請擅長此領域的行家幫忙解釋 非常感謝 #include #include #define DS1821_FCMD_READ_TEMPERATURE 0xAA #define DS1821_FCMD_START_CONVERT_T 0xEE #define DS1821_FCMD_STOP_CONVERT_T 0x22 #define DS1821_FCMD_WRITE_TH 0x01 #define DS1821_FCMD_WRITE_TL 0x02 #define DS1821_FCMD_READ_TH 0xA1 #define DS1821_FCMD_READ_TL 0xA2 #define DS1821_FCMD_WRITE_STATUS 0x0C #define DS1821_FCMD_READ_STATUS 0xAC #define DS1821_FCMD_READ_COUNTER 0xA0 #define DS1821_FCMD_LOAD_COUNTER 0x41 #define DS1821_CFG_DONE BIT7 #define DS1821_CFG_NVB BIT5 #define DS1821_CFG_THF BIT4 #define DS1821_CFG_TLF BIT3 #define DS1821_CFG_TR BIT2 #define DS1821_CFG_POL BIT1 #define DS1821_CFG_1SHOT BIT0 #define DS1821 BIT7 bool ds1821_reset(void); void ds1821_write_bit(uint8_t value); uint8_t ds1821_read_bit(void); void ds1821_write(uint8_t value); uint8_t ds1821_read(void); bool ds1821_reset(void) { bool ds1821_present = false; P1OUT &= ~DS1821; P1DIR |= DS1821; __delay_cycles(500); P1DIR &= ~DS1821; __delay_cycles(80); ds1821_present = ((P1IN & DS1821) == 0); __delay_cycles(420); return ds1821_present; } void ds1821_write_bit(uint8_t value) { P1OUT &= ~DS1821; P1DIR |= DS1821; if(value & 0x01) { __delay_cycles(8); P1DIR &= ~DS1821; __delay_cycles(57); } else { __delay_cycles(65); P1DIR &= ~DS1821; } __delay_cycles(5); } uint8_t ds1821_read_bit(void) { uint8_t value; P1OUT &= ~DS1821; P1DIR |= DS1821; __delay_cycles(3); P1DIR &= ~DS1821; __delay_cycles(5); value = ((P1IN & DS1821 == 0) ? 0 : 1); __delay_cycles(62); return value; } void ds1821_write(uint8_t value) { uint8_t mask; for(mask = 0x01; mask; mask <<= 1) { ds1821_write_bit((mask & value) ? 1 : 0); } } uint8_t ds1821_read(void) { uint8_t mask; uint8_t value = 0; for(mask = 0x01; mask; mask <<= 1) { if(ds1821_read_bit() == 1) { value |= mask; } } return value; } int main(void) { volatile bool ds1821_present = false; volatile uint8_t config_register = 0; volatile uint8_t temperature = 0; WDTCTL = WDTPW | WDTHOLD; BCSCTL1 = CALBC1_1MHZ; DCOCTL = CALDCO_1MHZ; BCSCTL2 = SELM_0 | DIVM_0 | DIVS_0; ds1821_present = ds1821_reset(); if(ds1821_present) { ds1821_write(DS1821_FCMD_START_CONVERT_T); do { ds1821_write(DS1821_FCMD_READ_STATUS); config_register = ds1821_read(); } while((config_register & DS1821_CFG_DONE) == 0); ds1821_write(DS1821_FCMD_READ_TEMPERATURE); temperature = ds1821_read(); } __nop(); __bis_status_register(LPM4_bits); }
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if8051
中階會員  發表：2 回覆：53 積分：61 註冊：2012-08-24 發送簡訊給我 |
請首先下載 DALLAS DS1821 18 頁 datasheet ，研究 1-wire bus
initialization timing & read / write time slot timing diagram Programmable Digital Thermostat and Thermometer Operates over a -55oC to 125oC temperature range 8 bit 1oC resolution 可建議使用解析度達 12 bit 0.0625oC 準確度 - 0.5oC 的 DS18B20 可接成多點系統，我使用經驗是並接 10 個 DS18B20 DQ 接到一點 MCU 輸入點。
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ATMEL AVR 單晶片設計開發 教學 工業電子 電機自動控制 設計 維修 |
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aki
版主 發表：30 回覆：696 積分：755 註冊：2004-01-15 發送簡訊給我 |
post 你的 E-mail 信箱,我有 DS1820 的範例給你參考! ===================引 用 specially527 文 章=================== 小弟最近在寫DS1821用於MSP430F449上的程式 對於下列程式碼的認知不是很清楚 懇請擅長此領域的行家幫忙解釋 非常感謝 #include #include #define DS1821_FCMD_READ_TEMPERATURE 0xAA #define DS1821_FCMD_START_CONVERT_T 0xEE #define DS1821_FCMD_STOP_CONVERT_T 0x22 #define DS1821_FCMD_WRITE_TH 0x01 #define DS1821_FCMD_WRITE_TL 0x02 #define DS1821_FCMD_READ_TH 0xA1 #define DS1821_FCMD_READ_TL 0xA2 #define DS1821_FCMD_WRITE_STATUS 0x0C #define DS1821_FCMD_READ_STATUS 0xAC #define DS1821_FCMD_READ_COUNTER 0xA0 #define DS1821_FCMD_LOAD_COUNTER 0x41 #define DS1821_CFG_DONE BIT7 #define DS1821_CFG_NVB BIT5 #define DS1821_CFG_THF BIT4 #define DS1821_CFG_TLF BIT3 #define DS1821_CFG_TR BIT2 #define DS1821_CFG_POL BIT1 #define DS1821_CFG_1SHOT BIT0 #define DS1821 BIT7 bool ds1821_reset(void); void ds1821_write_bit(uint8_t value); uint8_t ds1821_read_bit(void); void ds1821_write(uint8_t value); uint8_t ds1821_read(void); bool ds1821_reset(void) { bool ds1821_present = false; P1OUT &= ~DS1821; P1DIR |= DS1821; __delay_cycles(500); P1DIR &= ~DS1821; __delay_cycles(80); ds1821_present = ((P1IN & DS1821) == 0); __delay_cycles(420); return ds1821_present; } void ds1821_write_bit(uint8_t value) { P1OUT &= ~DS1821; P1DIR |= DS1821; if(value & 0x01) { __delay_cycles(8); P1DIR &= ~DS1821; __delay_cycles(57); } else { __delay_cycles(65); P1DIR &= ~DS1821; } __delay_cycles(5); } uint8_t ds1821_read_bit(void) { uint8_t value; P1OUT &= ~DS1821; P1DIR |= DS1821; __delay_cycles(3); P1DIR &= ~DS1821; __delay_cycles(5); value = ((P1IN & DS1821 == 0) ? 0 : 1); __delay_cycles(62); return value; } void ds1821_write(uint8_t value) { uint8_t mask; for(mask = 0x01; mask; mask <<= 1) { ds1821_write_bit((mask & value) ? 1 : 0); } } uint8_t ds1821_read(void) { uint8_t mask; uint8_t value = 0; for(mask = 0x01; mask; mask <<= 1) { if(ds1821_read_bit() == 1) { value |= mask; } } return value; } int main(void) { volatile bool ds1821_present = false; volatile uint8_t config_register = 0; volatile uint8_t temperature = 0; WDTCTL = WDTPW | WDTHOLD; BCSCTL1 = CALBC1_1MHZ; DCOCTL = CALDCO_1MHZ; BCSCTL2 = SELM_0 | DIVM_0 | DIVS_0; ds1821_present = ds1821_reset(); if(ds1821_present) { ds1821_write(DS1821_FCMD_START_CONVERT_T); do { ds1821_write(DS1821_FCMD_READ_STATUS); config_register = ds1821_read(); } while((config_register & DS1821_CFG_DONE) == 0); ds1821_write(DS1821_FCMD_READ_TEMPERATURE); temperature = ds1821_read(); } __nop(); __bis_status_register(LPM4_bits); }
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specially527
一般會員 發表：2 回覆：2 積分：0 註冊：2012-10-02 發送簡訊給我 |
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aki
版主 發表：30 回覆：696 積分：755 註冊：2004-01-15 發送簡訊給我 |
please confirm your e-mail account. and good luck! ===================引 用 specially527 文 章=================== specially527@hotmail.com 謝謝版主 麻煩你了 |
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specially527
一般會員 發表：2 回覆：2 積分：0 註冊：2012-10-02 發送簡訊給我 |
發表時間：2012-10-02 21:06:26
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