Blackbox reset after streaming GCODE via serial

Hi all,

I'm streaming GCODE directly to my Blackbox X32 via serial in a small Python script. The serial port is opened, GCODE commands are streamed to it, and the serial port is closed on exit. Works fine on the first try, but if the script is restarted, it hangs on the first instance of ser.readline(). If the firmware is restarted via the reset button on the X32, it runs fine again on the first try.

Any ideas on how to configure it such that no button-reset is required each time?

Cheers,
Miks

Sample code below:
------

class ControlBase(Node):

[..]

self.rail_interface = '/dev/ttyUSB0'
self.rail_baudrate = 115200
self.ser = None

self.ser = serial.Serial(self.rail_interface, self.rail_baudrate)
def send_wake_up(ser):
# Wake up
ser.write(str.encode("\r\n\r\n"))
time.sleep(2) # Wait for Printrbot to initialize
ser.flushInput() # Flush startup text in serial input

send_wake_up(self.ser)
time.sleep(1)
command = b'$X\n'
self.ser.write(command)
grbl_out = self.ser.readline() # Hangs here after script restart
print(f"{command} : " , grbl_out.strip().decode('utf-8'))
time.sleep(1)
command = b'G91\n'
self.ser.write(command)
grbl_out = self.ser.readline()
print(f"{command} : " , grbl_out.strip().decode('utf-8'))
time.sleep(1)
command = b'G21\n'
self.ser.write(command)
grbl_out = self.ser.readline()
print(f"{command} : " , grbl_out.strip().decode('utf-8'))
time.sleep(1)
print("Rail initialized")

[..]

self.ser.write(command) # GCODE written here asynchronously

[..]
# Cleanup
self.ser.flushInput()
self.ser.flushOutput()
self.ser.close()

 

Thanks Peter!
Played around with the DTR/RTS toggling on port opening, the following solved the issue:


self.ser = serial.Serial(
self.rail_interface,
self.rail_baudrate,
)

self.ser.dtr = False # Start with DTR low
self.ser.rts = False # Start with RTS low

time.sleep(0.5) # Wait a bit

self.ser.dtr = True # Then set DTR high
self.ser.rts = True # Then set RTS high