Hello everyone,


I cannot connect with Segger's RTT to my device directly after flashing another device, using the same jlink adapter. I hope somebody can help me with this.


We are creating a production tool to flash and test a product with 2 microcontrollers, using 1 Segger JLink base. The targets are:

• EFR32FG14PxxxF256, Silicon Labs
  
• PIC32MX440F128L, Microchip
  

The production programmer performs the following steps

Step 1:Flash the EFR32, we are using J-flash with SWD communication.

Step 2:Flash the PIC32, we are using J-Link with ICSP communication. Unfortunately, we cannot use JFlash, cause JFlash does not support this chip.

Step 3:After flashing the PIC32, we use JLink commander to create a telnet communication to communicate with the EFR32, using the RTT interface. We are using this communication to execute tests and receive the test results.


These steps work great separated but combined we have got stuck at the following problem. After the PIC32 firmware is flashed, and the JLink commander program is closed, the following tasks stays active for about 7 seconds: “JLinkGUIServer.exe”. When this task is active, we open a new JLink Commander program trying to connect to the EFR32. We receive the following string with telnet:“J-Link GUI server; V6.80d;”


In this situation we are not able to communicate with the EFR32FG14P over Segger’s RTT.


If we connect to the EFR32 with jlink after “JLinkGUIServer.exe” has closed, we get the following string with telnet: “SEGGER J-Link V6.80d - Real time terminal output”. Now we can successful communicate over Segger’s RTT with telnet.


How can we directly communicate with the EFR32 after the PIC32 is flashed? Is there a way to stop “JLinkGUIServer.exe” from starting, or to hide the GUI while flashing the device(-NoGui 1, does not work for this)? Is there a way to use JFlash instead of jlink, so we don’t have to use jlink to flash the PIC32?



Kind Regards,


Karel

Hi Fabian,

We connect to telnet by first connecting the device with Jlink, using the following command:


when connected to jlink, we can setup a telnet communication to the address: localhost:19021.
this works most of the time, it only doesn't work when “JLinkGUIServer.exe” is active. We setup the jlink communication directly after the PIC32 firmware flash.

If we put a 10 seconds delay between the PIC32 firmware flash and the jlink communication with the EFR32, “JLinkGUIServer.exe” quits after about 7 seconds, and it also works. But 10 seconds is a lot of time if this delay is to be used for every device for production programming. So we hope we can directly communicate with the EFR32 after the PIC32 firmware flash is finished.


Kind regards,


Karel

Hi Fabian,

The issue occurs when flashing the PIC32 with JLink, PIC32 flash with jflash is not possible with the current version, V6.80d. the situation is:

MCU1 = EFR32FG14PxxxF256
MCU2 = PIC32MX440F128L

We do the following steps:
1) JFlash to flash firmware MCU1
2) JLink to flash firmware MCU2
3) Jlink connect to MCU1
4) Link to telnet "localhost:1234"

We think the problem is the combination, flashing MCU2 with Jlink and after succesful flash, directly communicate with MCU1.

1) JFlash to flash firmware MCU1


2) JLink to flash firmware MCU2

3) Jlink connect to MCU1

Kind regards,

Karel

Hi Fabian,

No, unfortunately the "exit" at the end does not fix the issue.

Kind regards,

Karel

Hi Fabian,

We have tested your example, it works great and I think we have found the problem. After looking more in our production software, we find out the production software sets the first telnet port to 19022; "-rtttelnetport 19022". We think this telnetport is linked to "JLinkGUIServer.exe".

We have now set the telnet port in our production software to 1234, and it works perfect. I only have questions about the log, cause the log shows "TELNET listener socket opened on port 19022" when the telnet communication with jlink is successful and unsuccessful.

Thank you very much for your time and information.

Kind regards,

Karel