Which Pins are you using for UART4 rcv and have you set the PIN mux correctly for that PIN?
From: beagleboard@googlegroups.com [mailto:beagleboard@googlegroups.com] On Behalf Of Piyush Raj ae19m009 Sent: Monday, March 01, 2021 6:30 PM To: BeagleBoard <beagleboard@googlegroups.com> Subject: [beagleboard] POCKETBEAGLE: UART Help - Garbage data along with requisite data I am implementing UART using Pocketbeagle wherein i am trying to send simple strings over UART . I have written a code for loopback testing of UART-4 in PB. for a logic Low on P2.1 i am sending String "LOW" and "HIGH" for vice versa. However i am getting garbage data along with the requisite strings. sometimes all the received data is missing or broken. I tried to work at various baud rates (600, 9600,115200) but of no help. Am i doing any basic mistake. need guidance from community. (I worked with AVR and Arduino UART in the past and never faced such problem) Further, i also tried to dump the received data in a text file( to rule out possibility of terminal baud rate mismatch), but results did not change. My code is below: #include<fstream> #include<iostream> #include <string.h> #include <fcntl.h> #include <termios.h> #include<unistd.h> //for usleep #include"GPIO.h" using namespace exploringBB; using namespace std; int main() { GPIO outLogicSupply(60); outLogicSupply.setDirection(OUTPUT); GPIO inLogicSupply(59); inLogicSupply.setDirection(INPUT); int file,count; char transmit[6]; char receive[10]; int bytes_written,read_code;int count1=1; //////////////// OPENING UART4 ON POCKETBEAGLE ///////////////////// printf("UART: Transmission Started.\n"); if ((file = open("/dev/ttyO4", O_RDWR | O_NOCTTY | O_NDELAY))<0) { perror("UART: Failed to open the device.\n"); return -1; } else { printf("UART: Opened file successfully\n"); } ///////////////////////////////////////////////////////////////////// /////////////// SETTING UP UART OPTIONS /////////////////////////// struct termios options; tcgetattr(file, &options); options.c_cflag = B9600 | CS8 | CREAD | CLOCAL; options.c_iflag = IGNPAR | ICRNL; tcflush(file, TCIFLUSH); fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK); // make reads non-blocking tcsetattr(file, TCSANOW, &options); cout << "The value of the input is: "<< inLogicSupply.getValue() << endl; while(1) { if(inLogicSupply.getValue()==1) { strcpy(transmit,"HIGH\n"); outLogicSupply.setValue(HIGH); } else { strcpy(transmit,"LOW\n"); outLogicSupply.setValue(LOW); } bytes_written = write(file, &transmit,6); sleep(1); read_code= read(file,receive,10); if(bytes_written>0 && read_code>0 ) { receiveFile<<count1<<"sec - "<<receive; cout<<count1<<"sec - "<<receive; } count1++; sleep(0.01); } /////////////////////////////////////////////////////////////// receiveFile.close(); close(file); return 0; } -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com <mailto:beagleboard+unsubscr...@googlegroups.com> . To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/99530b73-a474-410b-8583-4d0327d32d35n%40googlegroups.com <https://groups.google.com/d/msgid/beagleboard/99530b73-a474-410b-8583-4d0327d32d35n%40googlegroups.com?utm_medium=email&utm_source=footer> . -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/000201d70f2a%24edd15100%24c973f300%24%40comcast.net.
