UniverSpace 2022 / Mbed 2 deprecated IniSat_TP5_Trame

IniSat Modèle 1 Version 2 TP 5 : Station Sol Exo 1 : Enregistrement GPS sur carte SD Exo 2 : Mise en place d'un protocole de communication avec la station sol

Dependencies:   mbed

Soft_UART/soft_uart.cpp@0:798c7207505d, 2022-05-31 (annotated)

Committer:
Giamarchi
Date:
Tue May 31 13:40:28 2022 +0000
Revision:
0:798c7207505d
MAJ

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Giamarchi 0:798c7207505d 1 // Software UART
Giamarchi 0:798c7207505d 2 //
Giamarchi 0:798c7207505d 3 // Generic software uart written in C, requiring a timer set to 3 times
Giamarchi 0:798c7207505d 4 // the baud rate, and two software read/write pins for the receive and
Giamarchi 0:798c7207505d 5 // transmit functions.
Giamarchi 0:798c7207505d 6 //
Giamarchi 0:798c7207505d 7 // * Received characters are buffered
Giamarchi 0:798c7207505d 8 // * putchar(), getchar(), kbhit() and flush_input_buffer() are available
Giamarchi 0:798c7207505d 9 // * There is a facility for background processing while waiting for input
Giamarchi 0:798c7207505d 10 //
Giamarchi 0:798c7207505d 11 // Colin Gittins, Software Engineer, Halliburton Energy Services
Giamarchi 0:798c7207505d 12 //
Giamarchi 0:798c7207505d 13 // The baud rate can be configured by changing the BAUD_RATE macro as
Giamarchi 0:798c7207505d 14 // follows:
Giamarchi 0:798c7207505d 15 //
Giamarchi 0:798c7207505d 16 // #define BAUD_RATE 19200.0
Giamarchi 0:798c7207505d 17 //
Giamarchi 0:798c7207505d 18 // The function init_uart() must be called before any comms can take place
Giamarchi 0:798c7207505d 19 //
Giamarchi 0:798c7207505d 20 // Interface routines required:
Giamarchi 0:798c7207505d 21 // 1. get_rx_pin_status()
Giamarchi 0:798c7207505d 22 // Returns 0 or 1 dependent on whether the receive pin is high or low.
Giamarchi 0:798c7207505d 23 // 2. set_tx_pin_high()
Giamarchi 0:798c7207505d 24 // Sets the transmit pin to the high state.
Giamarchi 0:798c7207505d 25 // 3. set_tx_pin_low()
Giamarchi 0:798c7207505d 26 // Sets the transmit pin to the low state.
Giamarchi 0:798c7207505d 27 // 4. idle()
Giamarchi 0:798c7207505d 28 // Background functions to execute while waiting for input.
Giamarchi 0:798c7207505d 29 // 5. timer_set( BAUD_RATE )
Giamarchi 0:798c7207505d 30 // Sets the timer to 3 times the baud rate.
Giamarchi 0:798c7207505d 31 // 6. set_timer_interrupt( timer_isr )
Giamarchi 0:798c7207505d 32 // Enables the timer interrupt.
Giamarchi 0:798c7207505d 33 //
Giamarchi 0:798c7207505d 34 // Functions provided:
Giamarchi 0:798c7207505d 35 // 1. void flush_input_buffer( void )
Giamarchi 0:798c7207505d 36 // Clears the contents of the input buffer.
Giamarchi 0:798c7207505d 37 // 2. char kbhit( void )
Giamarchi 0:798c7207505d 38 // Tests whether an input character has been received.
Giamarchi 0:798c7207505d 39 // 3. char getchar( void )
Giamarchi 0:798c7207505d 40 // Reads a character from the input buffer, waiting if necessary.
Giamarchi 0:798c7207505d 41 // 4. void turn_rx_on( void )
Giamarchi 0:798c7207505d 42 // Turns on the receive function.
Giamarchi 0:798c7207505d 43 // 5. void turn_rx_off( void )
Giamarchi 0:798c7207505d 44 // Turns off the receive function.
Giamarchi 0:798c7207505d 45 // 6. void putchar( char )
Giamarchi 0:798c7207505d 46 // Writes a character to the serial port.
Giamarchi 0:798c7207505d 47 #include "mbed.h"
Giamarchi 0:798c7207505d 48 #include <stdio.h>
Giamarchi 0:798c7207505d 49
Giamarchi 0:798c7207505d 50 #define BAUD_RATE 9600
Giamarchi 0:798c7207505d 51 #define IN_BUF_SIZE 256
Giamarchi 0:798c7207505d 52
Giamarchi 0:798c7207505d 53 #define TRUE 1
Giamarchi 0:798c7207505d 54 #define FALSE 0
Giamarchi 0:798c7207505d 55
Giamarchi 0:798c7207505d 56 static unsigned char inbuf[IN_BUF_SIZE];
Giamarchi 0:798c7207505d 57 static unsigned char qin = 0;
Giamarchi 0:798c7207505d 58 static unsigned char qout = 0;
Giamarchi 0:798c7207505d 59
Giamarchi 0:798c7207505d 60 static char flag_rx_waiting_for_stop_bit;
Giamarchi 0:798c7207505d 61 static char flag_rx_off;
Giamarchi 0:798c7207505d 62 static char rx_mask;
Giamarchi 0:798c7207505d 63 static char flag_rx_ready;
Giamarchi 0:798c7207505d 64 static char flag_tx_ready;
Giamarchi 0:798c7207505d 65 static char timer_rx_ctr;
Giamarchi 0:798c7207505d 66 static char timer_tx_ctr;
Giamarchi 0:798c7207505d 67 static char bits_left_in_rx;
Giamarchi 0:798c7207505d 68 static char bits_left_in_tx;
Giamarchi 0:798c7207505d 69 static char rx_num_of_bits;
Giamarchi 0:798c7207505d 70 static char tx_num_of_bits;
Giamarchi 0:798c7207505d 71 static int internal_rx_buffer;
Giamarchi 0:798c7207505d 72 static int internal_tx_buffer;
Giamarchi 0:798c7207505d 73 static int user_tx_buffer;
Giamarchi 0:798c7207505d 74
Giamarchi 0:798c7207505d 75 DigitalOut TX(PA_4);
Giamarchi 0:798c7207505d 76 DigitalIn RX(PA_3);
Giamarchi 0:798c7207505d 77 Ticker ticker;
Giamarchi 0:798c7207505d 78
Giamarchi 0:798c7207505d 79 //Background functions to execute while waiting for input.
Giamarchi 0:798c7207505d 80 void idle(){
Giamarchi 0:798c7207505d 81 wait_us(0.2);
Giamarchi 0:798c7207505d 82 }
Giamarchi 0:798c7207505d 83
Giamarchi 0:798c7207505d 84 //Sets the transmit pin to the high state.
Giamarchi 0:798c7207505d 85 void set_tx_pin_high() {
Giamarchi 0:798c7207505d 86 TX = 1;
Giamarchi 0:798c7207505d 87 }
Giamarchi 0:798c7207505d 88
Giamarchi 0:798c7207505d 89 //Sets the transmit pin to the low state.
Giamarchi 0:798c7207505d 90 void set_tx_pin_low() {
Giamarchi 0:798c7207505d 91 TX = 0;
Giamarchi 0:798c7207505d 92 }
Giamarchi 0:798c7207505d 93
Giamarchi 0:798c7207505d 94 //Returns 0 or 1 dependent on whether the receive pin is high or low
Giamarchi 0:798c7207505d 95 int get_rx_pin_status() {
Giamarchi 0:798c7207505d 96 return RX.read();
Giamarchi 0:798c7207505d 97 }
Giamarchi 0:798c7207505d 98
Giamarchi 0:798c7207505d 99 void timer_isr(void) {
Giamarchi 0:798c7207505d 100
Giamarchi 0:798c7207505d 101 char mask, start_bit, flag_in;
Giamarchi 0:798c7207505d 102
Giamarchi 0:798c7207505d 103 // Transmitter Section
Giamarchi 0:798c7207505d 104 if ( flag_tx_ready )
Giamarchi 0:798c7207505d 105 {
Giamarchi 0:798c7207505d 106
Giamarchi 0:798c7207505d 107 if ( --timer_tx_ctr <= 0 )
Giamarchi 0:798c7207505d 108 {
Giamarchi 0:798c7207505d 109 mask = internal_tx_buffer&1;
Giamarchi 0:798c7207505d 110 internal_tx_buffer >>= 1;
Giamarchi 0:798c7207505d 111 if ( mask )
Giamarchi 0:798c7207505d 112 {
Giamarchi 0:798c7207505d 113 set_tx_pin_high();
Giamarchi 0:798c7207505d 114 }
Giamarchi 0:798c7207505d 115 else
Giamarchi 0:798c7207505d 116 {
Giamarchi 0:798c7207505d 117 set_tx_pin_low();
Giamarchi 0:798c7207505d 118 }
Giamarchi 0:798c7207505d 119 timer_tx_ctr = 3;
Giamarchi 0:798c7207505d 120 if ( --bits_left_in_tx <= 0 )
Giamarchi 0:798c7207505d 121 {
Giamarchi 0:798c7207505d 122 flag_tx_ready = FALSE;
Giamarchi 0:798c7207505d 123 }
Giamarchi 0:798c7207505d 124 }
Giamarchi 0:798c7207505d 125 }
Giamarchi 0:798c7207505d 126 // Receiver Section
Giamarchi 0:798c7207505d 127 if ( flag_rx_off == FALSE )
Giamarchi 0:798c7207505d 128 {
Giamarchi 0:798c7207505d 129 if ( flag_rx_waiting_for_stop_bit )
Giamarchi 0:798c7207505d 130 {
Giamarchi 0:798c7207505d 131 if ( --timer_rx_ctr <= 0 )
Giamarchi 0:798c7207505d 132 {
Giamarchi 0:798c7207505d 133 flag_rx_waiting_for_stop_bit = FALSE;
Giamarchi 0:798c7207505d 134 flag_rx_ready = FALSE;
Giamarchi 0:798c7207505d 135 internal_rx_buffer &= 0xFF;
Giamarchi 0:798c7207505d 136 if ( internal_rx_buffer != 0xC2 )
Giamarchi 0:798c7207505d 137 {
Giamarchi 0:798c7207505d 138 inbuf[qin] = internal_rx_buffer;
Giamarchi 0:798c7207505d 139 if ( ++qin >= IN_BUF_SIZE )
Giamarchi 0:798c7207505d 140 {
Giamarchi 0:798c7207505d 141 qin = 0;
Giamarchi 0:798c7207505d 142 }
Giamarchi 0:798c7207505d 143 }
Giamarchi 0:798c7207505d 144 }
Giamarchi 0:798c7207505d 145 }
Giamarchi 0:798c7207505d 146 else // rx_test_busy
Giamarchi 0:798c7207505d 147 {
Giamarchi 0:798c7207505d 148 if ( flag_rx_ready==FALSE )
Giamarchi 0:798c7207505d 149 {
Giamarchi 0:798c7207505d 150 start_bit = get_rx_pin_status();
Giamarchi 0:798c7207505d 151 // Test for Start Bit
Giamarchi 0:798c7207505d 152 if ( start_bit == 0 )
Giamarchi 0:798c7207505d 153 {
Giamarchi 0:798c7207505d 154 flag_rx_ready = TRUE;
Giamarchi 0:798c7207505d 155 internal_rx_buffer = 0;
Giamarchi 0:798c7207505d 156 timer_rx_ctr = 4;
Giamarchi 0:798c7207505d 157 bits_left_in_rx = rx_num_of_bits;
Giamarchi 0:798c7207505d 158 rx_mask = 1;
Giamarchi 0:798c7207505d 159 }
Giamarchi 0:798c7207505d 160 }
Giamarchi 0:798c7207505d 161 else // rx_busy
Giamarchi 0:798c7207505d 162 {
Giamarchi 0:798c7207505d 163 if ( --timer_rx_ctr<=0 )
Giamarchi 0:798c7207505d 164 { // rcv
Giamarchi 0:798c7207505d 165 timer_rx_ctr = 3;
Giamarchi 0:798c7207505d 166 flag_in = get_rx_pin_status();
Giamarchi 0:798c7207505d 167 if ( flag_in )
Giamarchi 0:798c7207505d 168 {
Giamarchi 0:798c7207505d 169 internal_rx_buffer |= rx_mask;
Giamarchi 0:798c7207505d 170 }
Giamarchi 0:798c7207505d 171 rx_mask <<= 1;
Giamarchi 0:798c7207505d 172 if ( --bits_left_in_rx<=0 )
Giamarchi 0:798c7207505d 173 {
Giamarchi 0:798c7207505d 174 flag_rx_waiting_for_stop_bit = TRUE;
Giamarchi 0:798c7207505d 175 }
Giamarchi 0:798c7207505d 176 }
Giamarchi 0:798c7207505d 177 }
Giamarchi 0:798c7207505d 178 }
Giamarchi 0:798c7207505d 179 }
Giamarchi 0:798c7207505d 180 }
Giamarchi 0:798c7207505d 181
Giamarchi 0:798c7207505d 182 void Init_Soft_UART(void) {
Giamarchi 0:798c7207505d 183 flag_tx_ready = FALSE;
Giamarchi 0:798c7207505d 184 flag_rx_ready = FALSE;
Giamarchi 0:798c7207505d 185 flag_rx_waiting_for_stop_bit = FALSE;
Giamarchi 0:798c7207505d 186 flag_rx_off = FALSE;
Giamarchi 0:798c7207505d 187 rx_num_of_bits = 8; //10
Giamarchi 0:798c7207505d 188 tx_num_of_bits = 10; //10
Giamarchi 0:798c7207505d 189
Giamarchi 0:798c7207505d 190 set_tx_pin_high();
Giamarchi 0:798c7207505d 191 ticker.attach_us(&timer_isr, 1000000.0 / (BAUD_RATE * 3.0));
Giamarchi 0:798c7207505d 192 }
Giamarchi 0:798c7207505d 193
Giamarchi 0:798c7207505d 194 char _getchar(void) {
Giamarchi 0:798c7207505d 195 char ch;
Giamarchi 0:798c7207505d 196 do
Giamarchi 0:798c7207505d 197 {
Giamarchi 0:798c7207505d 198 while (qout == qin)
Giamarchi 0:798c7207505d 199 {
Giamarchi 0:798c7207505d 200 idle();
Giamarchi 0:798c7207505d 201 }
Giamarchi 0:798c7207505d 202 ch = inbuf[qout] & 0xFF;
Giamarchi 0:798c7207505d 203 if (++qout >= IN_BUF_SIZE)
Giamarchi 0:798c7207505d 204 {
Giamarchi 0:798c7207505d 205 qout = 0;
Giamarchi 0:798c7207505d 206 }
Giamarchi 0:798c7207505d 207 }
Giamarchi 0:798c7207505d 208 while (ch == 0x0A || ch == 0xC2);
Giamarchi 0:798c7207505d 209 return(ch);
Giamarchi 0:798c7207505d 210 }
Giamarchi 0:798c7207505d 211
Giamarchi 0:798c7207505d 212 void _putchar(char ch) {
Giamarchi 0:798c7207505d 213 while ( flag_tx_ready );
Giamarchi 0:798c7207505d 214 user_tx_buffer = ch;
Giamarchi 0:798c7207505d 215
Giamarchi 0:798c7207505d 216 // invoke_UART_transmit
Giamarchi 0:798c7207505d 217 timer_tx_ctr = 3;
Giamarchi 0:798c7207505d 218 bits_left_in_tx = tx_num_of_bits;
Giamarchi 0:798c7207505d 219 internal_tx_buffer = (user_tx_buffer<<1) | 0x200;;
Giamarchi 0:798c7207505d 220 flag_tx_ready = TRUE;
Giamarchi 0:798c7207505d 221 }
Giamarchi 0:798c7207505d 222
Giamarchi 0:798c7207505d 223 void flush_input_buffer(void) {
Giamarchi 0:798c7207505d 224 qin = 0;
Giamarchi 0:798c7207505d 225 qout = 0;
Giamarchi 0:798c7207505d 226 }
Giamarchi 0:798c7207505d 227
Giamarchi 0:798c7207505d 228 char kbhit(void) {
Giamarchi 0:798c7207505d 229 return( qin!=qout );
Giamarchi 0:798c7207505d 230 }
Giamarchi 0:798c7207505d 231
Giamarchi 0:798c7207505d 232 void turn_rx_on(void) {
Giamarchi 0:798c7207505d 233 flag_rx_off = FALSE;
Giamarchi 0:798c7207505d 234 }
Giamarchi 0:798c7207505d 235
Giamarchi 0:798c7207505d 236 void turn_rx_off(void) {
Giamarchi 0:798c7207505d 237 flag_rx_off = TRUE;
Giamarchi 0:798c7207505d 238 }
Giamarchi 0:798c7207505d 239
Giamarchi 0:798c7207505d 240 void printStr(char* str) {
Giamarchi 0:798c7207505d 241 int i = 0;
Giamarchi 0:798c7207505d 242 int len = strlen(str);
Giamarchi 0:798c7207505d 243 for(i = 0; i<len; i++){
Giamarchi 0:798c7207505d 244 wait(0.01);
Giamarchi 0:798c7207505d 245 _putchar(str[i]);
Giamarchi 0:798c7207505d 246 }
Giamarchi 0:798c7207505d 247 }
Giamarchi 0:798c7207505d 248