Set, read, and analyze um220 module data from the serial port

I haven't written a blog for a long time. Let's start a new journey from a small program;

The latest project mainly uses the Linux system. This article mainly introduces how to set and read the BD + GPS module (um220), which is actually mainly for serial port (UART) operations.

/* * gps.c * * um220 test * * Author: Wang Zhengkai <[email protected]> * */#include <stdio.h>#include <termios.h>#include <strings.h>#include <string.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>

/* I used a Ubuntu computer for testing, the serial port used is ttys0 */# define dev_node "/dev/ttys0" # define runtime 1024/* initialize serial port options */static void settermios (struct termios * pnewtio, int ubaudrate) {bzero (pnewtio, sizeof (struct termios);/* clear struct for new port settings * // 8n1pnewtio-> c_cflag = ubaudrate | cs8 | cread | clocal; pnewtio-> c_iflag = ignpar; pnewtio-> c_oflag = 0; pnewtio-> c_lflag = 0; // non Icanon}/* set the baud rate of the um220 serial port to 9600 and refresh to make it take effect immediately */void um220_uart_init (INT ttyfd, struct termios * oldtio, struct termios * newtio) {tcgetattr, oldtio);/* save current serial port settings */settermios (newtio, b9600); tcflush (ttyfd, tciflush); tcsetattr (ttyfd, tcsanow, newtio );} /* analysis data of um220 */void parsedata (char * BUF) {int NQ, NN, Nb, NC; char CX, Cy, cm1, cm2; float ftime, FX, FY, FP, FH, FB, FD; If (Buf = NULL) {printf ("error: Can't Get Buf! \ N "); return;} sscanf (BUF," $ gngga, % F, % F, % C, % F, % C, % d, % 02d, % F, % F, % C, % F, % C, % F, % 04d % 02x ", & ftime, & FX, & CX, & fy, & cy, & NQ, & NN, & FP, & FH, & cm1, & FB, & cm2, & FD, & nb, & NC); printf ("X: % C % F, Y: % C % F, H % F, satellite: % d \ n ", CX, FX, Cy, fy, FH, NN );

/* CX: N or S; FX: latitude; Cy: E or W; FY: longitude; FH: height; NN: number of satellites */} int main (void) {int Nb, command; int um220_fd =-1; char newbuf [max_packet_size]; char MSG [20], * ret = NULL; struct termios oldtio, newtio; /* Open um220 module */If (um220_fd = open (dev_node, o_rdwr) <0) {printf ("error: Can't open serial port % s! \ N ", dev_node); Return-1;}/* init UART for um220 */um220_uart_init (um220_fd, & oldtio, & newtio ); /* Set um220 options */printf ("Please select modules of um220 \ n"); printf ("1.bd module \ n"); printf ("2.gps module \ n "); printf ("3.bd+ GPS module \ n"); If (scanf ("% d", & command )! = 1) {printf ("error: input is wrong! \ N ");} switch (command) {Case 1: memset (MSG, 0, sizeof (MSG); strcpy (MSG," $ inclusys, h01 "); if (write (um220_fd, MSG, sizeof (MSG) <0) printf ("failed to set BD modules! \ N "); break; Case 2: memset (MSG, 0, sizeof (MSG); strcpy (MSG," $ inclusys, H10 "); If (write (um220_fd, MSG, sizeof (MSG) <0) printf ("failed to set GPS modules! \ N "); break; Case 3: memset (MSG, 0, sizeof (MSG); strcpy (MSG," $ inclusys, H11 "); If (write (um220_fd, MSG, sizeof (MSG) <0) printf ("failed to set BD + GPS modules! \ N "); break; default: printf (" can't identify command, set BD + GPS modules! \ N "); memset (MSG, 0, sizeof (MSG); strcpy (MSG," $ inclusys, H11 "); If (write (um220_fd, MSG, sizeof (MSG) <0) printf ("failed to set BD + GPS modules! \ N ") ;}for (;) {/* read data from um220 */memset (newbuf, 0, 1024); NB = read (um220_fd, newbuf, max_packet_size ); if (NB =-1) {perror ("read UART error"); Return-1;} If (ret = strstr (newbuf, "$ gngga "))! = NULL) {/* analysis data */parsedata (RET);} Sleep (1);}/* recover settings of serial port */tcsetattr (um220_fd, tcsanow, & oldtio);/* close um220_fd */close (um220_fd );

return 0;}

Set, read, and analyze um220 module data from the serial port