Mangnimit MCU / Mbed 2 deprecated Nucleo_dht11

read dht11 show on clcd

Dependencies:   mbed

main.cpp@0:8fe7d36af056, 2014-03-17 (annotated)

Committer:
JENG
Date:
Mon Mar 17 12:35:48 2014 +0000
Revision:
0:8fe7d36af056
basic interface read dht11 show on clcd

Who changed what in which revision?

UserRevisionLine numberNew contents of line
JENG 0:8fe7d36af056 1
JENG 0:8fe7d36af056 2 #include "mbed.h"
JENG 0:8fe7d36af056 3
JENG 0:8fe7d36af056 4 DigitalOut LCD_RS(D8);
JENG 0:8fe7d36af056 5 DigitalOut LCD_EN(D9);
JENG 0:8fe7d36af056 6 DigitalOut LCD_D4(D4);
JENG 0:8fe7d36af056 7 DigitalOut LCD_D5(D5);
JENG 0:8fe7d36af056 8 DigitalOut LCD_D6(D6);
JENG 0:8fe7d36af056 9 DigitalOut LCD_D7(D7);
JENG 0:8fe7d36af056 10
JENG 0:8fe7d36af056 11
JENG 0:8fe7d36af056 12 //########################################
JENG 0:8fe7d36af056 13 // LCD Library
JENG 0:8fe7d36af056 14 //########################################
JENG 0:8fe7d36af056 15
JENG 0:8fe7d36af056 16 //send data to lcd
JENG 0:8fe7d36af056 17 void write_lcd(uint8_t d){
JENG 0:8fe7d36af056 18
JENG 0:8fe7d36af056 19 LCD_D4 = (d & 0x10)?1:0;
JENG 0:8fe7d36af056 20 LCD_D5 = (d & 0x20)?1:0;
JENG 0:8fe7d36af056 21 LCD_D6 = (d & 0x40)?1:0;
JENG 0:8fe7d36af056 22 LCD_D7 = (d & 0x80)?1:0;
JENG 0:8fe7d36af056 23
JENG 0:8fe7d36af056 24 wait_us(2);
JENG 0:8fe7d36af056 25 LCD_EN = 1;
JENG 0:8fe7d36af056 26 wait_us(2);
JENG 0:8fe7d36af056 27 LCD_EN = 0;
JENG 0:8fe7d36af056 28
JENG 0:8fe7d36af056 29 }
JENG 0:8fe7d36af056 30
JENG 0:8fe7d36af056 31 //lcd write byte
JENG 0:8fe7d36af056 32 void lcd_write_byte(uint8_t byte){
JENG 0:8fe7d36af056 33
JENG 0:8fe7d36af056 34 write_lcd(byte);
JENG 0:8fe7d36af056 35 write_lcd(byte << 4);
JENG 0:8fe7d36af056 36
JENG 0:8fe7d36af056 37 }
JENG 0:8fe7d36af056 38
JENG 0:8fe7d36af056 39 //write command
JENG 0:8fe7d36af056 40 void lcd_putcmd(uint8_t c){
JENG 0:8fe7d36af056 41
JENG 0:8fe7d36af056 42 wait_ms(5);
JENG 0:8fe7d36af056 43 lcd_write_byte(c);
JENG 0:8fe7d36af056 44
JENG 0:8fe7d36af056 45 }
JENG 0:8fe7d36af056 46
JENG 0:8fe7d36af056 47 //write one char
JENG 0:8fe7d36af056 48 void lcd_putc(uint8_t d){
JENG 0:8fe7d36af056 49
JENG 0:8fe7d36af056 50 wait_ms(1);
JENG 0:8fe7d36af056 51 LCD_RS = 1;
JENG 0:8fe7d36af056 52 lcd_write_byte(d);
JENG 0:8fe7d36af056 53 LCD_RS = 0;
JENG 0:8fe7d36af056 54
JENG 0:8fe7d36af056 55 }
JENG 0:8fe7d36af056 56
JENG 0:8fe7d36af056 57
JENG 0:8fe7d36af056 58
JENG 0:8fe7d36af056 59 //print string
JENG 0:8fe7d36af056 60 void lcd_puts(char * p){
JENG 0:8fe7d36af056 61
JENG 0:8fe7d36af056 62 while(* p)lcd_putc(* p++);
JENG 0:8fe7d36af056 63
JENG 0:8fe7d36af056 64 }
JENG 0:8fe7d36af056 65
JENG 0:8fe7d36af056 66 //lcd initial interface
JENG 0:8fe7d36af056 67 void lcd_initial(void){
JENG 0:8fe7d36af056 68
JENG 0:8fe7d36af056 69 uint8_t x = 3;
JENG 0:8fe7d36af056 70
JENG 0:8fe7d36af056 71 LCD_RS = 0;
JENG 0:8fe7d36af056 72 LCD_EN = 0;
JENG 0:8fe7d36af056 73
JENG 0:8fe7d36af056 74 LCD_D4 = 0;
JENG 0:8fe7d36af056 75 LCD_D5 = 0;
JENG 0:8fe7d36af056 76 LCD_D6 = 0;
JENG 0:8fe7d36af056 77 LCD_D7 = 0;
JENG 0:8fe7d36af056 78
JENG 0:8fe7d36af056 79 wait_ms(50);
JENG 0:8fe7d36af056 80
JENG 0:8fe7d36af056 81 while(x--){
JENG 0:8fe7d36af056 82
JENG 0:8fe7d36af056 83 write_lcd(0x30);
JENG 0:8fe7d36af056 84 wait_ms(5);
JENG 0:8fe7d36af056 85
JENG 0:8fe7d36af056 86 }
JENG 0:8fe7d36af056 87
JENG 0:8fe7d36af056 88 write_lcd(0x20); //4bit interface
JENG 0:8fe7d36af056 89
JENG 0:8fe7d36af056 90 lcd_putcmd(0x28); //function set
JENG 0:8fe7d36af056 91 lcd_putcmd(0x08); //display off
JENG 0:8fe7d36af056 92 lcd_putcmd(0x01); //display clear
JENG 0:8fe7d36af056 93 lcd_putcmd(0x06); //entry mode set
JENG 0:8fe7d36af056 94 lcd_putcmd(0x0c); //display on
JENG 0:8fe7d36af056 95
JENG 0:8fe7d36af056 96 }
JENG 0:8fe7d36af056 97 //########################################
JENG 0:8fe7d36af056 98 // End of LCD Library
JENG 0:8fe7d36af056 99 //########################################
JENG 0:8fe7d36af056 100
JENG 0:8fe7d36af056 101 #define DHTLIB_OK 0
JENG 0:8fe7d36af056 102 #define DHTLIB_ERROR_CHECKSUM -1
JENG 0:8fe7d36af056 103 #define DHTLIB_ERROR_TIMEOUT -2
JENG 0:8fe7d36af056 104
JENG 0:8fe7d36af056 105 Timer tmr;
JENG 0:8fe7d36af056 106
JENG 0:8fe7d36af056 107 DigitalInOut data_pin(A1);
JENG 0:8fe7d36af056 108
JENG 0:8fe7d36af056 109 int humidity;
JENG 0:8fe7d36af056 110 int temperature;
JENG 0:8fe7d36af056 111
JENG 0:8fe7d36af056 112 //########################################
JENG 0:8fe7d36af056 113 // DHT11 Library
JENG 0:8fe7d36af056 114 //########################################
JENG 0:8fe7d36af056 115 int dht_read(void){
JENG 0:8fe7d36af056 116
JENG 0:8fe7d36af056 117 // BUFFER TO RECEIVE
JENG 0:8fe7d36af056 118 uint8_t bits[5];
JENG 0:8fe7d36af056 119 uint8_t cnt = 7;
JENG 0:8fe7d36af056 120 uint8_t idx = 0;
JENG 0:8fe7d36af056 121
JENG 0:8fe7d36af056 122 tmr.stop();
JENG 0:8fe7d36af056 123 tmr.reset();
JENG 0:8fe7d36af056 124
JENG 0:8fe7d36af056 125 // EMPTY BUFFER
JENG 0:8fe7d36af056 126 for(int i=0; i< 5; i++) bits[i] = 0;
JENG 0:8fe7d36af056 127
JENG 0:8fe7d36af056 128 // REQUEST SAMPLE
JENG 0:8fe7d36af056 129 data_pin.output();
JENG 0:8fe7d36af056 130 data_pin.write(0);
JENG 0:8fe7d36af056 131 wait_ms(18);
JENG 0:8fe7d36af056 132 data_pin.write(1);
JENG 0:8fe7d36af056 133 wait_us(40);
JENG 0:8fe7d36af056 134 data_pin.input();
JENG 0:8fe7d36af056 135
JENG 0:8fe7d36af056 136 // ACKNOWLEDGE or TIMEOUT
JENG 0:8fe7d36af056 137 unsigned int loopCnt = 10000;
JENG 0:8fe7d36af056 138
JENG 0:8fe7d36af056 139 while(!data_pin.read())if(!loopCnt--)return DHTLIB_ERROR_TIMEOUT;
JENG 0:8fe7d36af056 140
JENG 0:8fe7d36af056 141 loopCnt = 10000;
JENG 0:8fe7d36af056 142
JENG 0:8fe7d36af056 143 while(data_pin.read())if(!loopCnt--)return DHTLIB_ERROR_TIMEOUT;
JENG 0:8fe7d36af056 144
JENG 0:8fe7d36af056 145 // READ OUTPUT - 40 BITS => 5 BYTES or TIMEOUT
JENG 0:8fe7d36af056 146 for(int i=0; i<40; i++){
JENG 0:8fe7d36af056 147
JENG 0:8fe7d36af056 148 loopCnt = 10000;
JENG 0:8fe7d36af056 149
JENG 0:8fe7d36af056 150 while(!data_pin.read())if(loopCnt-- == 0)return DHTLIB_ERROR_TIMEOUT;
JENG 0:8fe7d36af056 151
JENG 0:8fe7d36af056 152 //unsigned long t = micros();
JENG 0:8fe7d36af056 153 tmr.start();
JENG 0:8fe7d36af056 154
JENG 0:8fe7d36af056 155 loopCnt = 10000;
JENG 0:8fe7d36af056 156
JENG 0:8fe7d36af056 157 while(data_pin.read())if(!loopCnt--)return DHTLIB_ERROR_TIMEOUT;
JENG 0:8fe7d36af056 158
JENG 0:8fe7d36af056 159 if(tmr.read_us() > 40) bits[idx] |= (1 << cnt);
JENG 0:8fe7d36af056 160
JENG 0:8fe7d36af056 161 tmr.stop();
JENG 0:8fe7d36af056 162 tmr.reset();
JENG 0:8fe7d36af056 163
JENG 0:8fe7d36af056 164 if(cnt == 0){ // next byte?
JENG 0:8fe7d36af056 165
JENG 0:8fe7d36af056 166 cnt = 7; // restart at MSB
JENG 0:8fe7d36af056 167 idx++; // next byte!
JENG 0:8fe7d36af056 168
JENG 0:8fe7d36af056 169 }else cnt--;
JENG 0:8fe7d36af056 170
JENG 0:8fe7d36af056 171 }
JENG 0:8fe7d36af056 172
JENG 0:8fe7d36af056 173 // WRITE TO RIGHT VARS
JENG 0:8fe7d36af056 174 // as bits[1] and bits[3] are allways zero they are omitted in formulas.
JENG 0:8fe7d36af056 175 humidity = bits[0];
JENG 0:8fe7d36af056 176 temperature = bits[2];
JENG 0:8fe7d36af056 177
JENG 0:8fe7d36af056 178 uint8_t sum = bits[0] + bits[2];
JENG 0:8fe7d36af056 179
JENG 0:8fe7d36af056 180 if(bits[4] != sum)return DHTLIB_ERROR_CHECKSUM;
JENG 0:8fe7d36af056 181
JENG 0:8fe7d36af056 182 return DHTLIB_OK;
JENG 0:8fe7d36af056 183
JENG 0:8fe7d36af056 184 }
JENG 0:8fe7d36af056 185
JENG 0:8fe7d36af056 186 char buffer[17];
JENG 0:8fe7d36af056 187
JENG 0:8fe7d36af056 188 //########################################
JENG 0:8fe7d36af056 189 // End of DHT11 Library
JENG 0:8fe7d36af056 190 //########################################
JENG 0:8fe7d36af056 191
JENG 0:8fe7d36af056 192 int main(void){
JENG 0:8fe7d36af056 193
JENG 0:8fe7d36af056 194 lcd_initial();
JENG 0:8fe7d36af056 195
JENG 0:8fe7d36af056 196 lcd_puts("=Nucleo - DHT11=");
JENG 0:8fe7d36af056 197
JENG 0:8fe7d36af056 198 for(;;){
JENG 0:8fe7d36af056 199
JENG 0:8fe7d36af056 200 if(!dht_read()){
JENG 0:8fe7d36af056 201
JENG 0:8fe7d36af056 202 //sprintf(buffer, "Temp %2d C ", temperature);
JENG 0:8fe7d36af056 203 //lcd_putcmd(0x80);
JENG 0:8fe7d36af056 204 //lcd_puts(buffer);
JENG 0:8fe7d36af056 205 sprintf(buffer, "Hum %2d%% Tmp %2dc", humidity, temperature);
JENG 0:8fe7d36af056 206 lcd_putcmd(0xc0);
JENG 0:8fe7d36af056 207 lcd_puts(buffer);
JENG 0:8fe7d36af056 208 wait(0.5);
JENG 0:8fe7d36af056 209
JENG 0:8fe7d36af056 210 }else{
JENG 0:8fe7d36af056 211
JENG 0:8fe7d36af056 212 lcd_putcmd(0x80);
JENG 0:8fe7d36af056 213 lcd_puts("Sensor Error !!!");
JENG 0:8fe7d36af056 214 lcd_putcmd(0xc0);
JENG 0:8fe7d36af056 215 lcd_puts(" ");
JENG 0:8fe7d36af056 216
JENG 0:8fe7d36af056 217 }
JENG 0:8fe7d36af056 218
JENG 0:8fe7d36af056 219 }
JENG 0:8fe7d36af056 220
JENG 0:8fe7d36af056 221 }