Ashwath M Pavithran
/
csi066_rev0p3_harald_prog
Publishing for sharing with Harald
Diff: I2C_read.cpp
- Revision:
- 3:3e8c16b6620c
- Child:
- 4:1c48c9fa44fc
diff -r c7229eac380b -r 3e8c16b6620c I2C_read.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/I2C_read.cpp Thu Jun 21 22:11:25 2018 +0000 @@ -0,0 +1,101 @@ +#include "mbed.h" + +extern Serial pc; +extern int frequ = 50; //unit kHz +extern char dev_addr = 0x00; //fixed + +char get_half_byte(int *flag) { + char cur_char; + cur_char = pc.getc(); + if ( cur_char >= '0' && cur_char <= '9' ) { + cur_char = cur_char - '0'; + *flag = 1; + } + else if ( cur_char >= 'a' && cur_char <= 'f') { + cur_char = cur_char - 'a'+10; + *flag = 1; + } + else if( cur_char >= 'A' && cur_char <= 'F') { + cur_char = cur_char - 'A'+10; + *flag = 1; + } + else *flag = 0; + return cur_char; +} + +void i2c_read() { + char reg_ptr = 0x55; + char reg_data = 0x00; + char temp; + int flag1 = 0; + char count = 0; + I2C i2c(p9,p10); + LPC_PINCON->PINMODE_OD0 = (LPC_PINCON->PINMODE_OD0 | 0x0003); // To make p9 & P10 open_drain + pc.printf("\n\n\n \r\tYahoooo! Lets read a Register"); + //Read the number of Registers + while (!flag1) { + pc.printf("\n\n\n\r\tEnter the number of registers to read (1 - 16) and hit 'enter' key: "); + temp = '0'; + count = 0; + while (temp != '\r') { //look for enter key + count = (count * 10) + (temp - '0'); // converting to number + temp = pc.getc(); + if ((temp < '0' || temp > '9') && temp !='\r') { + pc.printf(" \n\r\t\033[%dm Invalid Chracter!! No worries, let us try again \033[%dm",41,40); + break; + } + } + if (count >= 1 && count <= 16 && temp == '\r') flag1 = 1; + else if (temp == '\r') pc.printf(" \n\r\t\033[%dm Invalid Chracter!! No worries, let us try again \033[%dm",41,40); + } +Re_enter: + flag1 = 0; + //Read Pointer to the Register that needs to be read + while (!flag1) { + pc.printf("\n\n \r\tEnter Register Address in hex (0 to f): "); + reg_ptr = get_half_byte(&flag1); + if (flag1==0) pc.printf(" \033[%dm Invalid Chracter!! No worries, let us try again \033[%dm",41,40); + } + + pc.printf("\n\n\n\r\t\033[%dm", 44);//change backround to blue + pc.printf(" Device Address (fixed) = 0x%2.2X ; Register Pointer = 0x%2.2X ; Count = %d ",dev_addr, reg_ptr, count); + pc.printf("\033[%dm", 40);//change backround to black + + pc.printf("\n\n\n \r\tContinue Read? (y/n) [Press 'e' to re-enter Pointer]: "); + temp = 0; + while ( temp!='y' && temp!='n' && temp!='e') { + temp = pc.getc(); + } + if (temp == 'n') { + pc.printf("\n\n \r\tAborting Register Read :(\n\n\r"); + return; + } + if (temp == 'e') { + pc.printf(" \n\n\n \r\tOk, let us try again :)"); + goto Re_enter; + } + i2c.frequency(frequ*1000); + i2c.stop(); //add a stop after hot-read + wait_us(10); + for ( ; (count > 0) && (reg_ptr < 0x10); count = count - 1) { + i2c.start(); + flag1 = i2c.write(dev_addr); + if (flag1 != 1) pc.printf("\n\n\n \r\tNo Ack for dev addr :("); + flag1 = i2c.write(reg_ptr); + if (flag1 != 1) pc.printf("\n\n \r\tNo Ack reg pointer :("); + i2c.stop(); + wait_us(10); + i2c.start(); + flag1 = i2c.write(dev_addr | 0x01); //lsb 1 for read + if (flag1 != 1) pc.printf("\n\n \r\tNo Ack for dev addr :("); + reg_data = i2c.read(0); //0- donot send ack after read is done + pc.printf("\n\n\n \r\tRead 0x%2.2X = 0x%2.2X ", reg_ptr, reg_data); + wait_us(5); + i2c.stop(); + if (reg_data == 0xff) pc.printf(" |\033[%dm Register read might not be sucessfull \033[%dm ",45,40); + reg_ptr = reg_ptr + 1; + wait_us(120); + } + pc.printf("\n\n\n \r\tYeahhh! Register Read Complete\n\n\r"); + i2c.~I2C(); +} \ No newline at end of file