stlink v2 not connecting to stm32f405

[wv1106]

Hi everyone,

I recently build a custom PCB with a stm32f405, but every time I try to connect to it with a stlink v2 it gives an error.

 

Target no device found

Error in initializing ST-LINK device.
Reason: No device found on target.

 

I already managed to program a stm32 blue pill with the stlink, so I am starting to think the problem lies in my PCB.

Thanks in advance.

[AScha.3]

boot0 at gnd !

st-link -> CubeProgrammer -> connect : system software reset

should connect then!

[wv1106]

Still doesn't seem to work.

[TDK]

Your schematic symbol is missing pin 63 (VSS). If this is left unconnected on the board, it would explain the error.

 

[wv1106]

It indeed doesn't show in the schematic for some reason but it is connected.

 

[TDK]

> It indeed doesn't show in the schematic for some reason but it is connected.

Weird.

 

Measure VDD and VCAP to verify correct voltages.

If you have a counterfeit programmer like this, it could also be that the software doesn't like it.

 

[wv1106]

The VCAP voltages are way below what they should be. The VDD pins seem fine.

[TDK]

They should be ~1.2V. They're both way below that?

Verify proper part orientation. With the "STM32" text reading left to right, pin 1 is at the bottom left.

Verify good solder joints.

[wv1106]

Well this is embarrassing. My stm32 was indeed in a wrong orientation.

Thank you very much for your help.

[TDK]

You aren't the first and you won't be the last. It's confusing. Luckily, usually a mistake you only make once.