uart

I want to read data from UART, i followed this tutorial , the write function works as expected, however i'am getting problem with the read function : This is the uart_init function: void uart_init() { printf("\n +----------------------------------+"); printf("\n | Serial Port Write |"); printf("\n +----------------------------------+"); /*------------------------------- Opening the Serial Port -------------------------------*/ fd = open("/dev/ttyUSB0",O_RDWR | O_NOCTTY| O_SYNC); /* !!blocks the read */ /* O_RDWR Read/Write access to serial port */ /* O_NOCTTY - No terminal will control the

I am currently working with Gem5 and I have to access via UART from my Host to ARMv8 bare-metal option, so i tried lots way but i stocked yet. could you please let me know, how can i map my host's Serial port to ARMv8's Serial Port in bare-metal type programming. Any help would be appreciated Working setups This repository contains a highly automated working example . Features: works on both QEMU and gem5 works on both arm and aarch64 newlib allows using the standard C library optionally semihosting exemplified works on both RealViewPBX and VExpress_GEM5_V1 . You should prefer VExpress_GEM5_V1

I'm trying to receive a number through uart which is packed as a string. I'm sending number 1000, so I get 4 bytes + null character. But when I convert the array to number with atoi() and compare the integer with 1000 I don't always get a correct number. This is my interrupt handler function for receiving the number. What could be wrong? void USART1_IRQHandler(void) { if( USART_GetITStatus(USART1, USART_IT_RXNE) ) { char t = USART1->RDR; if( (t != '\n' && t!='\0') && (cnt < 4) ) { received_string[cnt] = t; cnt++; } else { cnt = 0; } t = 0; received_string[4] = 0; } if(cnt==4) { data = atoi

介绍 tcp作为服务端，监听端口8888，实现串口透传，这里是使用select监听tcp的receive和串口的read，单工通信 程序 #include <sys/types.h> #include <sys/socket.h> #include <arpa/inet.h> #include <unistd.h> #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <string.h> #include <errno.h> #include <stdlib.h> #include <linux/serial.h> #include <sys/ioctl.h> #include <sys/select.h> #include <termios.h> void Test_err(int flg) { if(flg<0) { perror(strerror(errno)); exit(1); } } int main(int argc, char** argv) { printf("usage : %s <port,default is 8888>\n",argv[0]); printf("tcp-server...enter\n"); unsigned char* uart_port="/dev

In a serial communication link, what is the prefered framing/sync method? framing with SOF and escaping sequences, like in HDLC? relying on using a header with length info and CRC? It's an embedded system using DMA transfers of data from UART to memory. I think the framing method with SOF is most attractive, but maybe the other one is good enough? Does anyone has pros and cons for these two methods? Following based on UART serial experience, not research. I have found fewer communication issues when the following are included - or in other words, do both SOF/EOF and (length - maybe)/checkcode.

以前并没有发现串口状态机的好处，以至于忘记了到底怎么用到底是干什么的，最近用到了这种指定格式的数据包解析，才发现这东西非常的好用，可以增加数据传输的鲁棒性，可以对串口的数据包进行过滤只解出符合协议的数据包。这个呢其实就是一种思想，不仅仅局限于串口之间的数据传输，我认为可以用在很多指定数据协议的数据包传输解析当中。大致代码思想写在下面，希望对大家有帮助。 /* 主要的变量声明在这边 /* 串口状态机宏 */ # define DATA_HEAD 3 # define DATA_LEN 4 # define DATA_COM 5 # define DATA_NUM 6 # define DATA_CRC 7 # define DATA_TAIL 8 # define DATA_ADD 9 # define COMMAND_SIZE 20 int g_count = 0 ; //状态机缓冲区下标 int g_uart_state = DATA_HEAD; //串口状态机状态标志 unsigned char data; //串口数据 //状态机缓冲区 unsigned char command_buf[COMMAND_SIZE] = { 0 }; unsigned char *bufptr = &data; while ( 1 ) { /* 从串口中一次只读取一个字符 */ retv =