DDA output not showing over serial communication with Rpi?

jazbaatbadalgaye

I am trying to capture the DDA output over serial on a Raspberry Pi. However the only data I am able to read over serial is the heater warning.

Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault

I am able to read the DDA output when I use a python script for serial communication but I am only getting the warning when I use C for serial communication.

The expected output i.e. the output from the python script is as follows :

N 0.500000 174.949997 112.449997 0.300000 0.000000 0.000000 0.000000 41926.273438 0.000000 41926.273438 83852 0.0000e+0 1.1926e-5 0.0000e+0 1 0.500000

N 15.100006 174.949997 112.449997 0.300000 15.100006 0.000000 0.000000 53037.558594 917231.625000 970269.187500 970269 0.0000e+0 1.6000e-5 1.6000e-5 1 1.265568

Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault

N 15.100006 190.050003 112.449997 0.300000 0.000000 15.100006 0.000000 0.000000 943750.375000 943750.375000 943750 1.6000e-5 1.6000e-5 1.6000e-5 1 1.265663

N 6.769390 169.649002 108.239998 0.300000 5.300995 4.209999 0.000000 96530.593750 0.000000 96530.593750 193061 0.0000e+0 7.0127e-5 0.0000e+0 1 0.000000
    
N 0.500000 174.949997 112.449997 0.300000 0.000000 0.000000 0.000000 41926.273438 0.000000 41926.273438 83852 0.0000e+0 1.1926e-5 0.0000e+0 1 0.500000
    
N 15.100006 174.949997 112.449997 0.300000 15.100006 0.000000 0.000000 53037.558594 917231.625000 970269.187500 970269 0.0000e+0 1.6000e-5 1.6000e-5 1 1.265568

Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault
    
N 15.100006 190.050003 112.449997 0.300000 0.000000 15.100006 0.000000 0.000000 943750.375000 943750.375000 943750 1.6000e-5 1.6000e-5 1.6000e-5 1 1.265663

i.e. a line starting with N and followed by some numerical values and occasionally get some warnings about the heater.

However, the output I am getting is

Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault
 
Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault
 
Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault
 
Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault
 
Warning: Tool 0 was not driven because its heater temperatures were not high enough or it has a heater fault

The c code that I am using is

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>

int main(int argc, char ** argv) {
  int fd;

  // Open the Port. We want read/write, no "controlling tty" status, and open it no matter what state DCD is in
  fd = open("/dev/ttyACM0", O_RDWR | O_NOCTTY | O_NDELAY);
  
  struct termios SerialPortSettings;
  
  cfsetispeed(&SerialPortSettings,B115200);
  cfsetospeed(&SerialPortSettings,B115200);
		
  tcsetattr(fd, TCSAFLUSH, &SerialPortSettings);

    
  if (fd == -1) 
  {
    perror("open_port: Unable to open /dev/ttyACM0 - ");
    return(-1);
  }

  // Turn off blocking for reads, use (fd, F_SETFL, FNDELAY) if you want that
  fcntl(fd, F_SETFL, 0);

  // Write to the port


  // Read up to 255 characters from the port if they are there

  char buf[255];
  
  while (1)
  {
    ssize_t k = read(fd, buf, sizeof(buf)-1);
    if (k < 0) 
    {
      perror("Read failed - ");
      return -1;
    } 
    else if (k == 0) 
    {
      printf("No data on port\n");
    }
    else 
    {
      buf[k] = '\0';
      printf(buf);
      
    }
  }
  
  close(fd);
  return 0;
}

I have used the same code to get some values from an accelerometer so I am confident that the code works, albeit bad code, but works. Does anyone have any idea why am I not able to read the numerical data but able to read the heater warnings?

Here is the python code which works properly :

import serial
import time
import subprocess

LINUX = 1

output = subprocess.check_output("python -m serial.tools.list_ports", shell=True) # sending command to terminal 
output = output.decode('utf-8') # the output is of type b'somestring' This removes that
output = output.splitlines() # so we can access the COM part

if LINUX:
    temp = output[0].split()
    port = temp[0]
else:
    port =  output[0]
    
data = open("Input.txt", "w")
ser = serial.Serial(port, 115200, timeout=30)
print("Serial Port opened on : " + ser.name)

counter = 0
while (1):
    response = ser.readline().decode('utf-8')
    print(response)
    data.write(response)
    if response == "":
        break

time.sleep(1)
data.close()

jazbaatbadalgaye

@jazbaatbadalgaye Just commenting in case anyone runs into the same issue.

The C code was working fine, void DDA::DebugPrint in DDA.cpp was the culprit. The debugPrintf() function in void DDA::DebugPrint did not output to the serial (at least in C, it worked fine in Python). So I declared variables in Platform.h, set values in DDA.cpp and used debugPrintf() in Platform.cpp to print all the values to serial. I have no idea why it works and I have no idea why the debugPrintf() function in void DDA::DebugPrint doesn't work in C. Maybe need to sacrifice a goat to the C Gods.

Note : All this is not required if using python to read serial data. For python, just print values using debugPrintf() function in void DDA::DebugPrint. Those values will show up on the serial.