Connect Problem with Repetier Firmware 0.82

hello ! everybody
After repeated test, I encountered a problem.
When I upload the Repetier firmware 0.82, Everything works good except the connect problem. The problem will be solved by replace the firmware of 0.81.
I have browsed the changelog.txt , I can't find something related.
grateful your help!

Are you sure it is not a different baudrate setting? 0.82 has now 115200 baud as default set, which was 250000 in previous version. Also eeprom settings may override this anyway.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

@repetier: Are you recommending 115200 for new versions going forward, or is it pretty much one of those things that if it works, it works? When I first tried your firmware, I thought 250000 was way too fast. At the time, I had been running Marlin and Sprinter at 115200. Now I think "Wow, 115200 is soooo slooow".

Thank you!
I have test all the possible Band Rate. All other Rates only feedback"Connected - 5 Command Waiting ",except the error rates. When I use the ArduinoIDE serial monitor check The error rates answer :" Resend:1 ok"

Thanks!
I find the problem. This because of the "External reset" followed the below commands

???Start
N0 M110 *3

and when I reset it handly,it works perfectly.
While the 0.81 start with:

ok 0
N0 M110 *3
ok

I want to know that Where the firmware is changed ? Caused different initial command.
Grateful your answers !

@jcabrer The reason I use 115200 baud is linux. Often I let my Raspberry Pi handle the printer and linux is awkward with non ansi baud rates. Some connections work with 250000 baud and some not. So now I configure my printer with 115200 to have a preset working with all os. For windows/mac only I would still prefer 250000.

@panxinlong7373 No start sequence hasn't changed. The start (with small s it should be) is the first send by the firmware on startup. Then the host responds with N0 M110 to reset line numbering. For a better insight you should enable logging for the host (Repetier-Settings) restart and then see what is written to the log file. It contains more information then you see in the normal log. Perhaps that would show where the problem occurs exactly.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

thank you very much!
I think these code my related to the result.
epr_init_baudrate();
RFSERIAL.begin(baudrate);
out.println_P(PSTR("start"));
UI_INITIALIZE;

byte mcu = MCUSR;
if(mcu & 1) out.println_P(PSTR("PowerUp"));
if(mcu & 2) out.println_P(PSTR("External Reset"));
if(mcu & 4) out.println_P(PSTR("Brown out Reset"));
if(mcu & 8) out.println_P(PSTR("Watchdog Reset"));
if(mcu & 32) out.println_P(PSTR("Software Reset"));
MCUSR=0;

"start" then the reg of MCUSR=0x02 , it send "External Reset"
Does it related to the bootloader or Watchdog settings ?
How to change it?

Ok, I have others with the same problem and reread all changes. Not sure which is the real reason, but I have a new favourite. Please try

#define FEATURE_CHECKSUM_FORCED false

in the configuration.h instead of true. It changes the handling of checksums to improve reliability (that was at least the idea) but may also cause the resend. Please report back if it helps.

What MCUSR contains is the reason for the restart. Some bootloaders overwrite the variable, but it is only aninformatve variable to know what happened, so you see in the logs why the firmware was restarted. It is not the root of your problem.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

I just uploaded version 0.82.2 which hopefully fixes these problems. If you can check with FEATURE_CHECKSUM_FORCED if that feature now works correctly. Is now disabled by default.

---

Repetier-Software - the home of Repetier-Host (Windows, Linux and Mac OS X) and Repetier-Firmware.
Repetier-Server - the solution to control your printer from everywhere.
Visit us on Facebook and Twitter!

I added this line in the configuration.h , it works well.

#define FEATURE_CHECKSUM_FORCED false, thing run smoothly.
#define FEATURE_CHECKSUM_FORCED true, error come back, and wait for external reset chip.
Thank your very much !

I have the same problem:

Received: start
Received: Info: External reset.

I have download Configuration and Firmware from the online tool (0.91 Rev 8). Suggestion? I have raspberry with octoprint and not Repeater-host connected.