Loading...
 

Zephyr project on STM32

   Zephyr Workbench, a VSCode extension to manage Zephyr on STM32.
It enables users to easily create, develop, and debug Zephyr applications.
Main features:
  • Install host dependencies.
  • Import toolchain and SDK.
  • Create, configure, build and manage apps.
  • Debug STM32.
You can directly download it from the VSCode marketplace
For more details, visit the Zephyr Workbench

System Workbench for STM32

Forum List Topic List

[ prev topic ]  

sprinf conversion of float is not working for STM32F7

Posted by Breinholm on 2016-02-16 10:33

I’m tryint to use sprintf to convert a float to a string, but the returned string is empty (just the ‘\0’ is returned).
Do any of you know of a trick that can make it work?

I’m using the latest versions of AC6 and the “Hello World” example from cube.

/Breinholm

Reads: 52851
Link
Posted by tarek bouchkati on 2016-02-16 10:58 Tunisia

Hello Breinholm,

Check your linker flags (project properties > C/C++ Build > Setings > Tool Settings (TAB) > MCU GCC Linker > Miscellaneous > Linker flags),
if you are using nanolib “-specs=nano.specs” you need to add “-u _printf_float” to enable float printf.

Best Regards,
TarekB

Link
Posted by sync1 on 2016-06-19 13:47

Hi Tarek,

I treid adding “-u _printf_float” to enable float printf. as you suggest but after build i get the following errors?


Building target: EM34.elf
Invoking: MCU GCC Linker
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -specs=nosys.specs -specs=nano.specs -Xlinker -u _printf_float -T”../STM32F103CBTx_FLASH.ld” -Wl,-Map=output.map -Wl,--gc-sections -lm -o “EM34.elf” @”objects.list”
arm-none-eabi-gcc.exe: error: _printf_float: No such file or directory
make: *** EM34.elf Error 1

I am using latest updates for STM32 CubeMX, and STM32 Workbench..... I recall this solution used to work on previuos version but not now?
Any suggestions?

Link
Posted by tang on 2016-06-20 11:13

Hi,

I think you put the “-u _printf_float” on the wrong place, it should be in the linker flags and not the -Xlinker area.

Regards
Kevin.

Link
Posted by sync1 on 2016-06-20 12:19

Hi Tang,

I am sure I put the options under the Linker Flags, as I said this option was working under previous versions (unsure which version it was) but I recently clicked “update” on both the STM32 CubeMX and the System32 Workbench programs and now for some unlknown reason The Linker throws the following errors:

Building target: EM34.elf
Invoking: MCU GCC Linker
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -specs=nosys.specs -specs=nano.specs -Xlinker -u _sprintf_float -Xlinker -u _printf_float -T”../STM32F103CBTx_FLASH.ld” -Wl,-Map=output.map -Wl,--gc-sections -lm -o “EM34.elf” @”objects.list”
arm-none-eabi-gcc.exe: error: _sprintf_float: No such file or directory
arm-none-eabi-gcc.exe: error: _printf_float: No such file or directory
make: *** EM34.elf Error 1

(see attached image)

LinkerSettings.png (42.06 Kb)
Link

Posted by tarek bouchkati on 2016-06-20 12:39 Tunisia

Kevin is right :
“-u _printf_float” should be after “-specs=nano.specs”

Notes :
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -mfloat-abi=soft -specs=nosys.specs -specs=nano.specs -Xlinker -u _sprintf_float -Xlinker -u _printf_float -T”../STM32F103CBTx_FLASH.ld” ....

  1. There is no “_sprintf_float”
  2. You do not need Xlinker options
  3. You should have only one -u _printf_float
  4. In (project properties > C/C++ Build > Setings > Tool Settings (TAB) > MCU GCC Linker > Miscellaneous > Linker flags),you should have ” -specs=nosys.specs -specs=nano.specs -u _printf_float”
Link
Posted by sync1 on 2016-06-20 13:22

Many thanks tarek,

My problem issue was that was adding the “-u_printf_float” option using the “ADD ICON” which put the required string into the TEXT BOX below ? ..
This was working ok on previous versions of Sytem32 Workbench ...but ... The Latest version doesn’t work like that anymore ... so what I did was to edit/replace the main string at the top ( -specs=nosys.specs -specs=nano.specs ) to what you have shown above .(-specs=nosys.specs -specs=nano.specs -u _printf_float). this worked OK ..
Thanks again for your help.biggrin

Link


 

Newest Forum Posts

  1. reservation car service Seattle by Jamesprede, 2025-05-01 10:06
  2. Last day: drone bonus by Danielrug, 2025-04-19 16:55
  3. SPI on Nucleo_STMH533RE by higginsa1, 2025-03-25 07:37
  4. SPI on Nucleo_STMH533RE by royjamil, 2025-03-23 11:31
  5. SPI on Nucleo_STMH533RE by higginsa1, 2025-03-23 09:33
  6. Configuring DMA for ADC in SW? by sam.hodgson, 2025-03-04 12:58
  7. Insightful Perspectives on This Subject by davidsycle, 2025-03-04 05:45
  8. Build a project in "release" mode by info@creosrl.it, 2025-02-20 18:12
  9. Build a project in "release" mode by info@creosrl.it, 2025-02-20 17:05
  10. Build a project in "release" mode by tang, 2025-02-20 10:36

Last-Modified Blogs

  1. System Workbench for STM32