lab_cactus / Mbed OS csi059

06/21/18

Fork of rtos_threading_with_callback by mbed_example

I2C_read.cpp@3:3e8c16b6620c, 2018-06-21 (annotated)

Committer:
CactusSemi
Date:
Thu Jun 21 22:11:25 2018 +0000
Revision:
3:3e8c16b6620c
06/21/2018

Who changed what in which revision?

UserRevisionLine numberNew contents of line
CactusSemi 3:3e8c16b6620c 1 #include "mbed.h"
CactusSemi 3:3e8c16b6620c 2
CactusSemi 3:3e8c16b6620c 3 extern Serial pc;
CactusSemi 3:3e8c16b6620c 4 extern int frequ = 50; //unit kHz
CactusSemi 3:3e8c16b6620c 5 extern char dev_addr = 0x00; //fixed
CactusSemi 3:3e8c16b6620c 6
CactusSemi 3:3e8c16b6620c 7 char get_half_byte(int *flag) {
CactusSemi 3:3e8c16b6620c 8 char cur_char;
CactusSemi 3:3e8c16b6620c 9 cur_char = pc.getc();
CactusSemi 3:3e8c16b6620c 10 if ( cur_char >= '0' && cur_char <= '9' ) {
CactusSemi 3:3e8c16b6620c 11 cur_char = cur_char - '0';
CactusSemi 3:3e8c16b6620c 12 *flag = 1;
CactusSemi 3:3e8c16b6620c 13 }
CactusSemi 3:3e8c16b6620c 14 else if ( cur_char >= 'a' && cur_char <= 'f') {
CactusSemi 3:3e8c16b6620c 15 cur_char = cur_char - 'a'+10;
CactusSemi 3:3e8c16b6620c 16 *flag = 1;
CactusSemi 3:3e8c16b6620c 17 }
CactusSemi 3:3e8c16b6620c 18 else if( cur_char >= 'A' && cur_char <= 'F') {
CactusSemi 3:3e8c16b6620c 19 cur_char = cur_char - 'A'+10;
CactusSemi 3:3e8c16b6620c 20 *flag = 1;
CactusSemi 3:3e8c16b6620c 21 }
CactusSemi 3:3e8c16b6620c 22 else *flag = 0;
CactusSemi 3:3e8c16b6620c 23 return cur_char;
CactusSemi 3:3e8c16b6620c 24 }
CactusSemi 3:3e8c16b6620c 25
CactusSemi 3:3e8c16b6620c 26 void i2c_read() {
CactusSemi 3:3e8c16b6620c 27 char reg_ptr = 0x55;
CactusSemi 3:3e8c16b6620c 28 char reg_data = 0x00;
CactusSemi 3:3e8c16b6620c 29 char temp;
CactusSemi 3:3e8c16b6620c 30 int flag1 = 0;
CactusSemi 3:3e8c16b6620c 31 char count = 0;
CactusSemi 3:3e8c16b6620c 32 I2C i2c(p9,p10);
CactusSemi 3:3e8c16b6620c 33 LPC_PINCON->PINMODE_OD0 = (LPC_PINCON->PINMODE_OD0 | 0x0003); // To make p9 & P10 open_drain
CactusSemi 3:3e8c16b6620c 34 pc.printf("\n\n\n \r\tYahoooo! Lets read a Register");
CactusSemi 3:3e8c16b6620c 35 //Read the number of Registers
CactusSemi 3:3e8c16b6620c 36 while (!flag1) {
CactusSemi 3:3e8c16b6620c 37 pc.printf("\n\n\n\r\tEnter the number of registers to read (1 - 16) and hit 'enter' key: ");
CactusSemi 3:3e8c16b6620c 38 temp = '0';
CactusSemi 3:3e8c16b6620c 39 count = 0;
CactusSemi 3:3e8c16b6620c 40 while (temp != '\r') { //look for enter key
CactusSemi 3:3e8c16b6620c 41 count = (count * 10) + (temp - '0'); // converting to number
CactusSemi 3:3e8c16b6620c 42 temp = pc.getc();
CactusSemi 3:3e8c16b6620c 43 if ((temp < '0' || temp > '9') && temp !='\r') {
CactusSemi 3:3e8c16b6620c 44 pc.printf(" \n\r\t\033[%dm Invalid Chracter!! No worries, let us try again \033[%dm",41,40);
CactusSemi 3:3e8c16b6620c 45 break;
CactusSemi 3:3e8c16b6620c 46 }
CactusSemi 3:3e8c16b6620c 47 }
CactusSemi 3:3e8c16b6620c 48 if (count >= 1 && count <= 16 && temp == '\r') flag1 = 1;
CactusSemi 3:3e8c16b6620c 49 else if (temp == '\r') pc.printf(" \n\r\t\033[%dm Invalid Chracter!! No worries, let us try again \033[%dm",41,40);
CactusSemi 3:3e8c16b6620c 50 }
CactusSemi 3:3e8c16b6620c 51 Re_enter:
CactusSemi 3:3e8c16b6620c 52 flag1 = 0;
CactusSemi 3:3e8c16b6620c 53 //Read Pointer to the Register that needs to be read
CactusSemi 3:3e8c16b6620c 54 while (!flag1) {
CactusSemi 3:3e8c16b6620c 55 pc.printf("\n\n \r\tEnter Register Address in hex (0 to f): ");
CactusSemi 3:3e8c16b6620c 56 reg_ptr = get_half_byte(&flag1);
CactusSemi 3:3e8c16b6620c 57 if (flag1==0) pc.printf(" \033[%dm Invalid Chracter!! No worries, let us try again \033[%dm",41,40);
CactusSemi 3:3e8c16b6620c 58 }
CactusSemi 3:3e8c16b6620c 59
CactusSemi 3:3e8c16b6620c 60 pc.printf("\n\n\n\r\t\033[%dm", 44);//change backround to blue
CactusSemi 3:3e8c16b6620c 61 pc.printf(" Device Address (fixed) = 0x%2.2X ; Register Pointer = 0x%2.2X ; Count = %d ",dev_addr, reg_ptr, count);
CactusSemi 3:3e8c16b6620c 62 pc.printf("\033[%dm", 40);//change backround to black
CactusSemi 3:3e8c16b6620c 63
CactusSemi 3:3e8c16b6620c 64 pc.printf("\n\n\n \r\tContinue Read? (y/n) [Press 'e' to re-enter Pointer]: ");
CactusSemi 3:3e8c16b6620c 65 temp = 0;
CactusSemi 3:3e8c16b6620c 66 while ( temp!='y' && temp!='n' && temp!='e') {
CactusSemi 3:3e8c16b6620c 67 temp = pc.getc();
CactusSemi 3:3e8c16b6620c 68 }
CactusSemi 3:3e8c16b6620c 69 if (temp == 'n') {
CactusSemi 3:3e8c16b6620c 70 pc.printf("\n\n \r\tAborting Register Read :(\n\n\r");
CactusSemi 3:3e8c16b6620c 71 return;
CactusSemi 3:3e8c16b6620c 72 }
CactusSemi 3:3e8c16b6620c 73 if (temp == 'e') {
CactusSemi 3:3e8c16b6620c 74 pc.printf(" \n\n\n \r\tOk, let us try again :)");
CactusSemi 3:3e8c16b6620c 75 goto Re_enter;
CactusSemi 3:3e8c16b6620c 76 }
CactusSemi 3:3e8c16b6620c 77 i2c.frequency(frequ*1000);
CactusSemi 3:3e8c16b6620c 78 i2c.stop(); //add a stop after hot-read
CactusSemi 3:3e8c16b6620c 79 wait_us(10);
CactusSemi 3:3e8c16b6620c 80 for ( ; (count > 0) && (reg_ptr < 0x10); count = count - 1) {
CactusSemi 3:3e8c16b6620c 81 i2c.start();
CactusSemi 3:3e8c16b6620c 82 flag1 = i2c.write(dev_addr);
CactusSemi 3:3e8c16b6620c 83 if (flag1 != 1) pc.printf("\n\n\n \r\tNo Ack for dev addr :(");
CactusSemi 3:3e8c16b6620c 84 flag1 = i2c.write(reg_ptr);
CactusSemi 3:3e8c16b6620c 85 if (flag1 != 1) pc.printf("\n\n \r\tNo Ack reg pointer :(");
CactusSemi 3:3e8c16b6620c 86 i2c.stop();
CactusSemi 3:3e8c16b6620c 87 wait_us(10);
CactusSemi 3:3e8c16b6620c 88 i2c.start();
CactusSemi 3:3e8c16b6620c 89 flag1 = i2c.write(dev_addr | 0x01); //lsb 1 for read
CactusSemi 3:3e8c16b6620c 90 if (flag1 != 1) pc.printf("\n\n \r\tNo Ack for dev addr :(");
CactusSemi 3:3e8c16b6620c 91 reg_data = i2c.read(0); //0- donot send ack after read is done
CactusSemi 3:3e8c16b6620c 92 pc.printf("\n\n\n \r\tRead 0x%2.2X = 0x%2.2X ", reg_ptr, reg_data);
CactusSemi 3:3e8c16b6620c 93 wait_us(5);
CactusSemi 3:3e8c16b6620c 94 i2c.stop();
CactusSemi 3:3e8c16b6620c 95 if (reg_data == 0xff) pc.printf(" |\033[%dm Register read might not be sucessfull \033[%dm ",45,40);
CactusSemi 3:3e8c16b6620c 96 reg_ptr = reg_ptr + 1;
CactusSemi 3:3e8c16b6620c 97 wait_us(120);
CactusSemi 3:3e8c16b6620c 98 }
CactusSemi 3:3e8c16b6620c 99 pc.printf("\n\n\n \r\tYeahhh! Register Read Complete\n\n\r");
CactusSemi 3:3e8c16b6620c 100 i2c.~I2C();
CactusSemi 3:3e8c16b6620c 101 }