ZProbing implementation

[trustfm]

I am using teacup as a pick and place machine.
I have variable height (Z) colums so i use ZMax endstop as sensor.
I use the
G162 Z100 Command for example
This goes down 100 if i get no click i know that the columd is empty else i do a pick and place movement

This is implemented like this :

Clock.h
uint8_t ZPolling;
int32_t ZMaxRuntime;

---

clock.cpp

static void clock_10ms(void) {
	// reset watchdog
	wd_reset();

	temp_sensor_tick();

	ifclock(clock_flag_250ms) {
		clock_250ms();
	}
  
  
	//Get current Z position : by trustfm
  if (ZPolling==1) {
  	update_current_position();
    if (current_position.axis[Z]<(int32_t)(Z_MAX * 1000.) && current_position.axis[Z]>(int32_t)(Z_MIN * 1000.))  {
      sersendf_P(PSTR("ZCur: %lq\n"),current_position.axis[Z] );
      if (current_position.axis[Z]>ZMaxRuntime) {  
      
        sersendf_P(PSTR("noClick\n"));
		
        timer_stop();
        queue_flush();
        timer_init();
		
      }
    }
  }
                 
} 

---

gcode_process.c

			case 162:
				//? --- G162: Home positive ---
				//?
				//? Find the maximum limit of the specified axes by searching for the limit switch.
				//?
        #if defined X_MAX_PIN
          if (next_target.seen_X)
            home_x_positive();
        #endif
        #if defined Y_MAX_PIN
          if (next_target.seen_Y)
            home_y_positive();
        #endif
        #if defined Z_MAX_PIN
          if (next_target.seen_Z) {
            ZMaxRuntime=next_target.target.axis[Z];
            ZPolling=1; //by TrustFm
            home_z_positive();
            ZPolling=0; //by TrustFm
          }
        #endif
				break;

Now the question : extremely rarely we get the machine stalled is there any possibility that specially
timer_stop();
queue_flush();
timer_init();
is the problem ?
Can this be implemented differently ?
Via serial i get "E:start" seems to restart arduino ...

I have tried to not flush the hole queue i have made a custom queue_next but does not seem to work as expected.
Thank you for your time

[Wurstnase]

timer_stop() is like riding a bike and throwing a stick of wood in your front wheel to stop.

Take a look into dda.c and the homing procedures. You could extend this with a new command, where the max end position is a bit different and it is not zeroing.

[phord]

The homing works by setting the position to an extreme position (dir * MAX_DELTA_UM) and stopping when the endstop is triggered. If you add a home command which uses a different target number instead of the extreme position, then I think it will mostly do what you want.

[phord]

I have a commit that records the position where the endstop was triggered. I needed it for Z-Probing the bed using the BLTouch probe. Maybe you can use something similar for your purposes. The change is here, but I haven't tested it with many different printer configs.

[trustfm]

Thank all of you for your support but my problem was bigger.
Even with a fresh (unchanged) teacup i got stalls and random "start"strings using putty.
For example
(
M106 S255
G90
M114
M106 S0
G162
G28 Z
M114
G162 Z
M106 S255
G28 Z
M114
)

got errors and corrupted status messages like X:120.000start ...

I figured out that had to do with the XON/XOFF implementation and my crappy CH340 clone arduino board. I have tested another one with the FTDI chip (arduino duemillanove) and worked perfectly.
I have found this source : https://github.com/grbl/grbl/wiki/Interfacing-with-Grbl
"Streaming Protocol: Via Flow Control (XON/XOFF)"

What system hw and sw is suggested using teacup ? At this point the options are only FTDI chips ?

[Wurstnase]

got errors and corrupted status messages like X:120.000start ...

It could help, when you post exactly what you've send and received.

Do you have any issues when XON/XOFF is disabled? XON/XOFF disabled is the default setting.

[trustfm]

I discovered that either enabled or disabled XON/XOFF CH340 chip stalls. (TX/RX Leds turn off)
I made a thread-free freepascal app to test it and i discovered the problem.
I always use synaser library. It is pretty stable and cross-platpform

{
In this test

TEACUP + FTDI + XONXOFF ---> WORKS
TEACUP + FTDI ---> DO NOT WORKS
TEACUP + CH340+ XONXOFF ---> DO NOT WORKS
TEACUP + CH340 ---> DO NOT WORKS

}

procedure Connect(ComPort:string);
var XONXOFF:boolean;
begin
BlockSerial:=TBlockSerial.Create;
BlockSerial.RaiseExcept:=true;
BlockSerial.ConvertLineEnd:=true; //http://synapse.ararat.cz/doku.php/public:howto:readdata
try

BlockSerial.LinuxLock:=false;
BlockSerial.Connect(ComPort);
XONXOFF := false;
BlockSerial.Config(250000,8,'N',SB1,XONXOFF,false);  //These values work with Grbl. Set the baud rate to 250000 as 8-N-1 (8-bits, no parity, and 1-stop bit.)



BlockSerial.DTR := true;
BlockSerial.RTS := false; 

except
on E : Exception do begin
ShowMessage(E.ClassName + ' error raised, with message : ' + E.Message);
end;
end;
end;

procedure TForm1.ButtonConnectClick(Sender: TObject);
begin
Connect('COM4'); //COM4

end;

procedure TForm1.ButtonSendReceiveClick(Sender: TObject);
var msg:string; i:integer;
begin

for i:=0 to 1000 do begin

  if BlockSerial.CanWrite(1000) then begin
    //BlockSerial.SendString('M114'); //no works
    BlockSerial.SendString('M114' + #10);
    BlockSerial.SendString('G90' + #10);
    BlockSerial.SendString('M114' + #10);
    //BlockSerial.SendString('G90' + #10#13);//just wrong
  end;

  sleep(100);


  while BlockSerial.WaitingDataEx > 0 do begin 
     Memo1.Lines.Add(IntToStr(i) + BlockSerial.Recvstring(-1) );  
  end;

end;

end;

[trustfm]

Hello i have some good news !
I have made a custom arduino trasnsmission tester CH340.
I have noticed that arduino clones using CH340 does not work (program stalls) but with trustduino (a mine single PCB arduino board) with the CH340 chip works !!!
I include the schematics and PCB of trustdino. The transmission tester is also in the zip file

http://trustfm.net/hardware/Images/Trustduino/tinyserialv1.0.zip

PS : my crude endstop implementation with the
timer_stop();
queue_flush();
timer_init();
sequence seems to work too with the FTDI and mine trustduino CH340 based board !!!