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DMart.16
Associate II
August 10, 2021
Solved

[SOLVED] Nucleo STM32l4R5ZI Vref Buffer stuck on Timeout

Hello,

I am trying to output the reference voltage for the DAC in a Nucleo L4R5ZI, I am doing so with the Vref Buffer. I am using STM32CubeIDE.

After creating a default project I just disabled all the communication I wasn't going to need and I configured the Vref Buffer in the SYS tab: Scale 0 (2.048v) and as output.

CubeMX generates a project that doesn't work. After some debuging I found that the function: HAL_SYSCFG_EnableVREFBUF() returns a timeout. After a search in Google I found a similar question and the solution given was to enable the RCC SYSCFG clock before hand, but that is enabled a couple of lines before enabling the Vref Buffer in my generated code, so that appears to not be the problem.

I am not sure if the problem is in the actual timeout (some problem with the clock) or if the Vref Buffer is just not being enabled propperly, thus causing the timeout.

I can't get it to work, I have uploaded the .ioc file in case you want to try it out.

Thank you so much

This topic has been closed for replies.
TDK
TDKBest answer
August 10, 2021

You'll need to disconnect VREF+ from AVDD by removing SB149.

0693W00000D22OkQAJ.png 

0693W00000D22P9QAJ.png

"If you feel a post has answered your question, please click ""Accept as Solution""."

3 replies

waclawek.jan
Super User
August 10, 2021

How is the VREF+ pin connected externally?

Get the schematics to your board and check the related solder bridges.

JW

TDK
TDKBest answer
August 10, 2021

You'll need to disconnect VREF+ from AVDD by removing SB149.

0693W00000D22OkQAJ.png 

0693W00000D22P9QAJ.png

"If you feel a post has answered your question, please click ""Accept as Solution""."
DMart.16
DMart.16Author
Associate II
August 11, 2021

That was it!

I also had to bridge (was OFF, now ON) SB119 to access VREF+ via Pin 6 of CN7 and Pin 7 of CN12.

Thank you so much!