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st link v2 red led is on

osman2
Associate II

Hello
The LED on the top link is red. Is it a problem with the connection or the driver? I can't figure it out. Can you help me?

14 REPLIES 14
Andrew Neil
Evangelist III

Please see this for how to capture a screenshot - far better than photographing the screen!

https://www.techrepublic.com/article/how-to-take-screenshots-in-windows-10/

 

The pop-up message is telling you that it can't detect any connected STM32 target device:

AndrewNeil_0-1730973673941.png

 

The log shows you that the target supply voltage is only 0.46V

AndrewNeil_2-1730973783592.png

Your Target can't be running with less than half a volt supply!

You need to fix the power supply on the target.

Note that the ST-Link/V2 does not supply power to the target.

 

Andrew Neil
Evangelist III

The meaning of the LED is described in the User Manual:

AndrewNeil_3-1730974074858.png

https://www.st.com/resource/en/user_manual/um1075-stlinkv2-incircuit-debuggerprogrammer-for-stm8-and-stm32-stmicroelectronics.pdf#page=15

 

So the PC is communicating with the ST-Link, but the ST-Link has not yet had any communication - successful or otherwise - with the Target.

As described in my previous post, your ST-Link can't communicate with your Target because the Target has no power.

The ST-Link can't distinguish this condition from simply having no target connected at all.

I know how to take a screenshot but the computer I took it on didn't have internet so I took it with my phone

Should I connect another device to the st-link instead of the computer's usb port?
Thank you for your interest

I apologize, but I plugged it into other ports, but for some reason the voltage does not increase and stays at 0.46


@osman2 wrote:

I plugged it into other ports, but for some reason the voltage does not increase and stays at 0.46


Again, the ST-Link does not supply power to the Target.

Your screenshot shows that the PC is communicating fine with the ST-Link;  there is no problem there - no need to try different USB ports.

The problem is that your Target is not powered.

How are you trying to power the Target?

What Target is it?

dear andrew
no cable is currently connected to the st link- cn3 socket

You don't have anything connecting to Pin 1 which should be the VTarget voltage to power the interface buffers on the ST-LINK side

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Up vote any posts that you find helpful, it shows what's working..

Do I need to give 3.3v from pin1 of the cn3 socket?


@osman2 wrote:

no cable is currently connected to the st link- cn3 socket


That's where you would connect the cable from the ST-Link to you Target.

If you have nothing connected there then, clearly, the ST-Link will not see any Target connected!

In this situation, the Red LED illuminated is the expected condition - as explained earlier.

 

AndrewNeil_1-1730980089721.png

Have you studied the User Manual?