Erratic behavior while programming STM32F767VG based prototype board

[allantommathew]

Posted on September 22, 2017 at 13:31

Hi Madam/Sir,

We have designed a prototype board based on STM32F767VG. It is configured to work for a couple of seconds (take a picture, send it via UART) and go to sleep (so that it consumes the least power). Initially I was able to program and debug the controller without any issues using all the tools mentioned below. But after a couple of days the programming became erratic. At times I was able to program the board but most of the time I'll get an error. I have used both,

ST-Link V1 and STM32 Nucleo-144 development board to program the prototype but both fails. 

Softwares Used:

IDE: IAR Embedded Workbench 8.11

Tools Used: ST Visual Programmer 3.4, STM32 ST-Link Utility 4.1

Programmer Used: ST-Link V1, STM32 Nucleo-144

Errors: 'ST-Link Connection Error', 'ST-Link Error'

I'm ready to share the technical details of the project. I'm not sure what is needed to find out the problem. I would be obliged if someone could shed some light on the problem that I am facing. 

Thank You.

With Regards,

Allan Tom Mathew.

#st-link-error #unable-to-program #stm32f767vg #stm32 #fatal-error:-st-link #stm32f767 #st-link-connection-error #stm32f7 #erratic

[Tesla DeLorean]

Posted on September 22, 2017 at 15:35

If the part goes to sleep or you disable the SWD pins communication will be difficult.

Review your options to 'Connect under Reset', or pull the BOOT0 pin High so that it doesn't run your code and turn the device off.

[Vangelis Fortounas]

Posted on September 22, 2017 at 15:55

The ''ST-Link Connection Error'' from EWARM means that the target is not connected.

Try to connect to target with ''Hardware reset'' option.

also in stlink utility

When in Stop or Standby power mode, the debug capability is disabled by default and the only way to communicate with core via swd is to give a hardware reset. (exception is when in DBGMCU_CR register has set the appropriate bits to give the debug functionality in LP modes)

Regards

[allantommathew]

Posted on September 25, 2017 at 12:17

Hi,

Thank you

Turvey.Clive.002

and

FORTOUNAS.EVANGELOS

for the quickand detailed reply. Appreciate the help. And I'm sorry for the late reply.

I did apply

Vangelis' solutionbut the problem still persists. I did not understand Clive's part of the solution, ''

it doesn't run your code and turn the device off''. TheBOOT0pin is right now pulled low with a 10K resistor.

Update:

1. Instead of going to sleep I'm right now giving a delay for the same time, but still the problem persists.

2. If I were toapply a little pressure on the board at a particular side I'm able to program the board like usual. So I thought it was a mechanical error and I made a second board,

but the latter too has the same issue.

I will upload the schematics ofthe board fora better understanding.

[Vangelis Fortounas · Accepted solution]

Posted on September 25, 2017 at 13:44

Hello!

The NRST pin in your schematic is strongly pulled High by 10K resistor.

This resistor can be omited or have a higher value.

It pulls up the NRST pin and may cause problems on POR or/and other resets.

Regards

vf

[allantommathew]

Posted on September 26, 2017 at 09:38

Hi

FORTOUNAS.EVANGELOS

‌,

Thank you for the reply. The problem with the circuit was the issuethat you pointed out. I removed the 10K resistor and I'm able to program the board without any issues. The mistake was subtle and thank you for pointing it out.

In the same project, I have stumbled upon a problem

withSTEVAL-SP1ML915

which seems to be kinda basic. I have made another thread for help.If you have worked with it, it would have been good to have a pair of fresh eyes into the issue. I'm attaching the link for the thread with this.

Link:

https://community.st.com/0D50X00009XkdijSAB

Thank You again for the help. Really appreciate it.

Thank You.

With Regards,

Allan Tom Mathew.