STM32CubeProgrammer is not able to successfully connect to or flash an STM32L471. This is a long-standing problem. I have no problem flashing other STM32L parts such as L051 and I have no problem flashing the L471 using an STLinkv2.

_dalbert · ‎2020-11-10

When you place the STM32L471 in DFU mode and attempt to connect via UART, the following is displayed in STM32CubeProgrammer:

14:39:27 : STM32CubeProgrammer API v2.5.0

14:39:28 : Serial Port COM9 is successfully opened.

14:39:28 : Port configuration: parity = even, baudrate = 115200, data-bit = 8, stop-bit = 1.0, flow-control = off

14:39:29 : Timeout error occured while waiting for acknowledgement.

14:39:29 : Activating device: OK

14:39:29 : Chip ID: 0x415

14:39:29 : BootLoader protocol version: 3.1

It clearly sees the chip and communicates with it, but it never enters the connected state. A second attempt to connect indicates that the UART is busy (i.e. a thread is likely hung up in the STM32CubeProgrammer application) and I must exit the app and re-enter to access the COM port again. This is under Windows 10 x64. Everything works fine with other STM32L processors, but not with the L471. This issue has been open for several years and it would be awesome if ST would address it. Thanks!

Houda GHABRI · ‎2020-11-13

Hi @Community member ,

Thanks for rising this issue .

Indeed the problem was reproduced and transferred to the devlopmenet team to be treated in future CubeProgarmmer release.

Best regards,

Houda

Pieter Conradie · ‎2021-11-08

Hi @Houda GHABRI ,

I've downloaded and tried STM32CubeProgrammer v2.8.0 with a STM32L471RET and am experiencing the same problem as reported by @dalbert a year ago. Unfortunately I do not have access to the SWD pins and the UART ROM bootloader is the only way that I can program the target.

Can you confirm that the development team are working on fixing this bug? How soon will a fixed version of STM32CubeProgrammer be available?

Thanks in advance,

Pieter

https://piconomix.com

Pieter Conradie · ‎2021-11-08

Hi @Houda GHABRI ,

Apologies! :( I had a mixed up installation of STM32CubeProgrammer. The uninstaller for v2.5.0 was missing and I had to go Administrator to get it removed.

I can confirm that v2.8.0 actually works 😊

Kind regards,

Pieter

https://piconomix.com

Houda GHABRI · ‎2021-11-08

Hello @Pieter Conradie

Glad to hear it works for you 😊

Houda