Using Printf Debugging, LIVE expressions and SWV Trace in CubeIDE || STM32 || ITM || SWV

[@ControllersTech]

the write function is as mentioned below: int _write(int file, char *ptr, int len) { /* Implement your write code here, this is used by puts and printf for example */ int i=0; for(i=0 ; i

[@asaf6391]

Is it possible to use this function to write to a text file as well in some way? If you can help me with that I will be glad.

[@iforce2d]

Thanks, very helpful! Small addition: if you don't have a newline at the end of what you're printf-ing, nothing will show up until a very large buffer has been filled, then you get it all at once, on a single line. At least that's my experience.

[@AryanSingh-by7ee]

Worked! was facing the same issue thanks!

[@chrisrogers5415]

Brilliant! Slow and careful explanation - unlike 99% of other tech channels!

[@faithhl7421]

I have been binge watching your STM32 videos. They are well thought through and thorough. Thank you, Arun.

[@xiaoyi982]

I've been helped. This is a great tutorial! Keep up the good work.

[@smitpatel1315]

Hello , Guys.. This person has shown a true configuration for using printf() function. If you facing issue in printing context using printf() , then please try to use "/n" after the writing the context in printf() function. printf("hello world") -> Nothing will print on SWV ITM Data Console printf("hello world/n") -> Proper Output on serial console...

[@CircuitandoEL]

Hey! Thanks for your support! It help me a lot!

[@paulg.3067]

Your intro destroyed my apartment!

[@ControllersTech]

haha.. I am working on changing it.

[@gunterotte]

Thanks. For the STM32F429i-DISCO, you need to solder SB9 (to connect SWO-PB3 to the ST-LINK) to make it work.

[@TheZeroomg]

Could you elaborate which pin should i solder SB9 to? The datasheet shows that when SB9 is ON, SWO signal of connector CN2 is connected to PB3.

[@gunterotte]

@@TheZeroomg SB9 is a Solder Bridge. Just connect the bridge with solder.

[@harrymagooslum5770]

Your videos are fabulous and quite empowering! I have two questions: How can I contribute some money to help fund more of the same? And if that is a computer voice on the video, can you share what technology is being used? I'd love to know. This virtual world is without borders and everyone benefits from the sharing of knowledge. Thank you SO MUCH, once again!

[@ControllersTech]

1. To contribute, just go to the website ( link is in the description) and at the end of every post, there is a donation link. 2. Yes. I use Amazon polly for the voice over.

[@Youngduck93]

Works like a charm! Thanks!

[@estebanvidal721]

I didnt see your video and im already loving you

[@NithinVarghese-zk4vt]

I TRIED THE SAME WRITE FUNCTION, BUT IT'S SHOWING UNDEFINED REFERENCE TO ITM_SendChar,,,,,,how to solve that? 😞

[@paulg.3067]

I just want to mention that after 4 hours searching for the error, re-wiring my hardware twice, changing cables, rewriting projects... printf("...") was not printing anything in the DATA CONSOLE because I FORGOT the LINEBREAK (" ")!!! So printf("Hello stupid") prints nothing, printf("Hello stupid ") prints it correctly...

[@ControllersTech]

Haha can't do anything about that. Problem with the software itself..

[@mauricio533]

You saved me a lot of time!

[@dipchakraborty5795]

I did the same thing, but what the explanation behind this?

[@ManoharEmandi]

​@@dipchakraborty5795stdout buffer needs to be flushed to print the string, is the canonical method to flush the stdin buffer, instead you can even use fflush() from stdlib.h

[@relcominc.9647]

IT WORKS! THANK YOU!

[@NotNotAsian]

Hi there. I am using a STM32F401, after following these instructions "live expressions" works. printf/"data trace" however doesn't :( I set a breakpoint on printf and stepped through, the ITM_SendChar puts the char into the port correctly but nothing is sent. I was wondering if this guide is still accurate?

[@prajaktagavandi6058]

Thanku for this video may god bless you

[@tomioyamaguchi9996]

why STM do not support printf() in STM32CubeIDE ? Seems me, this function is very useful and commonly provided almost IDE's. Is there any reason avoiding implement ?

[@gaelvangheluwe2923]

thanks for the extremely good content quality ! What's your OS desktop environment ? it's smooth

[@eduardodelarosaferrer2205]

Simply perfect !!

[@stm32user]

hi, thank you so much, Now I am new to this cubeide

[@SUPERGOOSE-LLC]

Alternatively, you could overwrite __io_putchar(). _write() calls __io_putchar.

[@noweare1]

Thank you for this. What is the serial comm program are you using it looks like it is integrated with eclipse.

[@ControllersTech]

it's the serial console and by default integrated with the IDE.

[@BilginistAdam]

so helpful, thank you bro.

[@SalarAzad]

sooo helpful, thank you!!!

[@bennguyen1313]

I'm using STM32CubeIDE version 1.2.1 on a Nucleo board (STM32H743 has an stlinkv3 v3.J6.m2), but I can't find where to set HCLK. I've enabled SWV in the debugger config and set the clock there, but not in the project. My HAL_Delay (1000) is *way* longer than a second so the default is probably wrong. Also, I've included stdio.h however, I don't see the "Hello World" in any of the window views (Console, Debugger Console, SWV Data Trace Timeline Graph, SWV ITM Data Console). In the SWV view properties, I've enabled Comparators 0 and *1* (although that don't seem to be necessary), and checked the ITM Stimulus Port bit 0, and the red 'Start Trace' record button is set. Could the HCLK setting also be causing the ITM_SendChar to fail? I assume the ST-Link's usb connector, when not programming, just passes the SWV data to/from the cpu? UPDATE: Pressing the Blue MX button on the right doesn't seem to do anything, but double clicking the .ioc file did! After checking the clock speed shown in the Clock Configuration (64Mhz) and applying it to the SWV Debugger Clock speed it worked! Would be nice for ITM record to start automatically, but what exactly does enabling the stimulus bit 0 do?

[@deniverreinkeschiitz5497]

Hi, thank you for the video. Works great, however, only in .c files. Is there a way to work in cpp files?

[@alexmayer8877]

Thanks! Really helpful :)

[@rameshwarnagargoje9319]

I am using STM32F407VG board, shows error while debugging i.e. " Error in final launch sequence: Failed to execute MI command: load "G:\\udemy\\embedded c\\my_workspace\\target\\001HelloWorld\\Debug\\001HelloWorld.elf" Error message from debugger back end: Error finishing flash operation "

[@domagojtomic1469]

Great video! What IDE theme are you using?

[@ControllersTech]

Darkest dark theme

[@IosifIliese]

It doesn't show anything for me either (stm32f429I-DISC1). I connected the PB3 pin of the microcontroller to the SWO pin of the debugger with a wire. It started displaying characters, but not the string "Hello world". I changed in Serial Wire Viewer, Core Clock (MHz) to 16.0, and it displayed the string "Hello world" 😃.

[@luisticona8475]

Change the core speed

[@samsman007]

I use F103 and genuine ST-Link, but it doesn't work!

[@sertackaantokyay5344]

I really big thank you to you

[@ir_wm_irsyaduddin]

why my nucleo f302r8 is not working, it does not showing any printf output

[@Lokanadya]

I'm using a STM32L151CB and a legit ST-Link/V2 Isol. (Own custom PCB) Strangely, when i click "start trace", the square around the circle lights up, then, when i press resume, the circle is greyed and unselected. No data shows up in either of the SWV tabs, but i have the live expressions working fine.

[@CaliBeta]

I'm using a f103c8 and the same thing happens to me, I can't print anything on the console and the record button turns gray when I start debugging

[@ControllersTech]

It won't work if you are using cloned ST link. Read other comments, someone have shared a solution where you might have to solder a wire in the stlink.

[@CaliBeta]

@@ControllersTech thanks 👊🏼👌🏼

[@glewiss6696]

Hello, I tried to set up the printf debuging with the bluepill board and the st_link v2 chinese dongle but can't make it work. The variable "count" in the live expression and the led toggle work but I got nothing on the console editor...Any idea? Thanks

[@glewiss6696]

I found it! This was due to the chinese st-link-v2 dongle that does not include TRACESWO pin !

[@eduardoblotta7914]

Hi Controllers Tech, thanks for the clear explanation. I could made a debug session but only show debug data in step by step execution. Any idea? Thanks again.

[@ControllersTech]

I don't understand what are u trying to ask..

[@antoinenauzet1568]

Hello, Thank you for this tutorial! Really usfull. Two questions - The printf are working even when I do not activate any comparator. Is it normal? - When activating the comparator 1 (with address 0x0), it display a "data" 0x0 in the SWV Data trace Timeline Graph. Is it still the comparator 1 that should activate printf?

[@Pendududesign]

Thank you very much. The live expression works but the graph and the console doesn’t work with an official nucleo stm32L432kc. Do you have an idea where this problem comes from ? :)

[@ControllersTech]

It doesn't work for some microcontrollers, specially the L series.

[@ControllersTech]

It doesn't work with f103c8 by default with the cloned st link. Though you can solder the swv pin to the st link. Google this, there are some solutions available. Or join that telegram group, some people in the group made it work

[@lukaspetrikas6320]

Hello. What if ITM is not available? I am programming stm32wb55 Nucleo board and I am trying to setup printf for debugging. This method does not seem to work due to the microcontroller not supporting ITM

[@ControllersTech]

Use uart.. it's faster..

[@lukaspetrikas6320]

@@ControllersTech For UART, I need to use external terminal program which is not convenient. I want to be able to debug printf in the same IDE I am working with

[@nangelo0]

WOW dark theme!

[@ControllersTech]

Yeah. Love for darkness

[@alexsh1046]

@@ControllersTech Where can I find this theme? :)

[@NNHGroup]

@@ControllersTech Please guide me to specialize in dark theme.

[@ControllersTech]

Goto help -> eclipse marketplace -> popular, and install darkest dark theme.

[@NNHGroup]

@@ControllersTech Thank you 3000!

[@amrmusa7217]

i have done the same procedure but neither the itm data trace nor the time line graph showed any thing

[@malkin_laboratory4692]

Thanks! Now, I'm trying to make scanf input, but no results..

[@ControllersTech]

I don't think scanf works with MCUs

[@mr.engineer3040]

ITM debugging is only for Cortex-M3 / Cortex-M4 / Cortex-M7 chips. Make sure your stm32 has one of the aforementioned controller.

[@Stimmenhotel]

I am using a STM32F303K8, according to this: www.st.com/en/microcontrollers-microprocessors/stm32f303.html it is a M4... But I wasn't able to get any output, not even character by using ITM_SendChar( 65 ) for an A ...

[@ksaisko]

@@Stimmenhotel Same!! it's not working on my STM32F446RE

[@ControllersTech]

This video is shot on f446RE itself

[@ksaisko]

I know this video is shot on f446re, that’s why it’s really strange it’s not working on mine, i followed all the step and nothing’s working! I did not forget the and , i don’t understand.

[@ControllersTech]

2 things. 1. Make sure you enable the swv(trace asynchronous) in the cubemx.. it's in sys settings 2. Make sure you turn on the recording button before running the code in the debugger

[@ahmedsiddique863]

worked more or less with stm32f3discovery. one small problem though, in live expression "Target not available" was displayed in place of value for count variable.

[@ControllersTech]

Load it again... It's a common problem.. I mean put the value in the watch again, whenever you see that error

[@julianh.7130]

Not working on Nucleo F303RE before setting Debug Mode to Trace Asynchronous Sw. After that it just works fine!

[@chepel5663]

Hi. Do you know why? I have the same board (NUCLEO-F303RE), and it not work the setting SWV.

[@michaczajka3854]

Im using STM32F411CEU6 and i cant set this, Debug Mode to Trace Asynchronous Sw becouse it has pink color and there is warning that says "This periherial has no parameters to be configured" can you help me with that? Of course entire printf thing doesn't work for me :/

[@dimaabualfoul9281]

it works thanks

[@SimonYells]

I think God punishes me because I made exactly the same thing as you and nothing happens. I use the original ST-Link V2 debugger and STM32F446RET MCU. Edit: After 7 month of trying this again on my Nucleo, now it works!

[@ControllersTech]

Maybe u forgot tu press record button

[@SimonYells]

@@ControllersTech I wish that was the solution, but sadly not.

[@SimonYells]

@@ControllersTech Btw, I saw another tutorial about printf with MCUs from STM32F series and the guy set the SYS mode in CubeMX to "Trace Asynchronous SW". You left it disabled, so I'm confused about whether I should leave it as default (disabled) or change it to Asynchronous SW. Any idea?

[@ControllersTech]

You should turn it on.. i left it coz it was working without turning it on too. But of it's not working for u, than u should turn it on

[@Stimmenhotel]

@@SimonYells Same Problem here, using a STM32F303K8 (Cortex M4) board. Even enabled the "Trace Async SW" ... Clock Speed I use the value from HCLK i set in CubeMX. Did you make it work?

[@MclarenF1rocket]

It works even if you don't enable SWD in CubeMX ? How would it know what debug protocol you are using?

[@ControllersTech]

Even I wondered the same. Maybe that's the default case. Anyway, i didn't dug deep into it as it was working and that's all we need 😏

[@electricalcoder3025]

but when i use any Hal_delay function in my int main while loop along with printf it doesnt print ot any thing on the console

[@ControllersTech]

Check your clock configuration.. hal delay shouldn't be an issue unless your clock setup is wrong

[@electricalcoder3025]

@@ControllersTech ​ i was using HSI which is of 16mhz as the system clock so i configured 16 mhz (default) itself in the debug configurations too. Moreover i tried creating a new project and same is the result when i treid to debug and put the breakpoints its moving fine in the while loop without any stuck but iam not getting any out in the particular console but when i trield 100ms delay after flashing the program and wating for the ouput .it gave me the output but the print on the console is comming to laggy and sometimes wont print even if the printf functon is in the while loop

[@ControllersTech]

Printf won't print in milliseconds.. i think it needs atleast 1 second delay... The swo clock is not as fast as mcu, so don't expect printf to work in 100s milliseconds.. If you need something like that, use uart

[@jakubstejskal6806]

Hi. Thank you for this video! But I've got a problem: SWW trace and SWV ITM console do not shows any data. Live expressions works fine. Any advice? Thank you

[@ControllersTech]

Which controller are u using ?

[@jakubstejskal6806]

@@ControllersTech STM32F103C8 aka Bluepill

[@ControllersTech]

This works with nucleo and discovery boards because they have an inbuilt ST-Link. You can't use it with f103 and chinese stlink varient. You might have to use a j-link or original st link with f103. Although i am not sure about those also, as I have never used them.

[@jakubstejskal6806]

​@@ControllersTech I am new here, all my experiences are with arduino IDE, so I do not understand your answer well but thanks anyway! Doesn't really matter right now, I am glad for succesfull upload code via ST-link (I was about to give up while trying properly install eclipse+OCD+..+..)

[@rcinfla9017]

@@jakubstejskal6806 There are videos and info how to modify one of the cheap Chinese Clone STLINK V2 to provide SWO input by cutting the 5v supply connector runner from USB Vbus and connecting pin 31 on the STM32 in the STLINK. www.eevblog.com/forum/microcontrollers/quick-hack-to-get-swo-on-st-link-clones/ It is a tight soldering job to connect to pin 31 without creating a solder bridge to adjacent pins so you need a fine point solder tip. The two 5v pins on the STLINK clone are given up to the SWO input. You may have to update the STLINK firmware if you did not previously done. You can also download STLINK code into a Blue Pill to create an STLINK V2 with SWO function. This SWO port is included on the Nucleo STLINK V2-1 board. The Nucleo boards also have UART2 from target uC fed over USB to a virtual COM port on PC using a terminal program of your choice to display the UART2 communications. You won't get the UART2 comm port on the STLINK V2 clone.

[@ACc-dd5bf]

Is it possible to have the swv console always active? I hate clicking the record button every time.

[@ControllersTech]

sadly no

[@cemulasatar]

SWV is working with the frequency of 16 MHZ but it didnt work with 168 MH.. Why ? my board ( stm32f407g)

[@cemulasatar]

I changed my 16 Mhz to 168 Mhz in debug configurations and also i checked clock frequaency on STM32cube but i didnt see anything on SWV data console

[@robertcanberkozturk7725]

based thanks

[@sandeepsiv]

I am using STM32L475 ..will it work ? I am using micro usb only.

[@nielspaulin2647]

Very helpful.

[@theraja011]

Dear sir, pls share any example code regarding gsm communication with stm 32 microcontroller..

[@undercrackers56]

Does anyone know where we can find ST Micro tutorials on how to use these various features?

[@vinothkannan1570]

In STM32 HAL and LL , which one is best for creating big and complex projects ??

[@ControllersTech]

LL is better if you can handle it. HAL is easier way out, but it's too much bloated

[@vinothkannan1570]

@@ControllersTech Can you make one video on SPI using LL library . i have tried but not working

[@ControllersTech]

Nope. That's not going to happen. I have already covered registers..

[@ozgurkayabasi588]

Good jop! Thank you.

[@ESEben10]

Nice video. Although it doesn't work for me. Nothing is printed. I use an ST board as a debuguer for another board.

[@khaliltroudy9908]

how can I get assisted while I'm writing the instructions ( I have to write the full instruction..) :/

[@ControllersTech]

Press control and space

[@ucannguyen4291]

Hi AD, let make a video about stm32 vs AS608 fingerprint sensor. I see everyone use it throw arduino but i don't know how to use it with stm32. Thanks a lot!!!

[@ControllersTech]

Sure. Maybe in near future

[@noweare1]

STM32 F0 doesn't support the SWV (viewer) , too bad

[@think7677]

I have try this but not give ouput in swt port.

[@colinwong3982]

Hi. Is it possible to save the port values to a text file?

[@bdouram]

Exists one way to save the data log from SWV trace into a txt file?

[@asaf6391]

Were you able to generate such a log file?

[@axelschmidt5716]

Hello, it's a great series with many information. One question: does it work with tasks? Meaning some printf in tasks don't show at my board. Does anyone have a solution?

[@ControllersTech]

It does work with tasks. If you look into my free rtos videos ( the first few), i have usee it in one of them...

[@BastiBas94]

it looks like you got a reset button for the debugger. if so, how do i get the button ?

[@BastiBas94]

i found it myself. for anyone else with the problem, go to windows->perspective -> open perspective -> debug

[@Androniy10]

Discovery board as st-link, own board with stm32f103. It doesn't work. ((

[@ControllersTech]

In F103 controller, you have to connect the pin PB3 to the SWO of the debugger. It's not available on the Chinese ST-Link, but if someone have the original ST-Link, they can do that. You try to find the SWO of the ST-Link (your discovery board) and connect to PB3 of F103

[@Androniy10]

Now PB3 is busy. When I used IAR, I didn't connect TRACESWO(PB3) pin, but printf worked fine. May be you know how it work in IAR? Thank you for answer.

[@ControllersTech]

No i don't know much about IAR. Maybe you shouldn't keep PB3 busy with any other task.

[@furkanklc5220]

How can I use this mmethod for STM32F103? Can you tell me the way?

[@ControllersTech]

You have to buy the original stlink. It won't work for the chinese versions

[@furkanklc5220]

@@ControllersTech Thank you! For the Keil compiler Is the video valid?

[@ControllersTech]

I don't know about that. If keil supports the ITM stimulus port, than it will work..

[@rubens5563]

This works great with STlink V2 (Chinese version): lujji.github.io/blog/stlink-clone-trace/

[@khoatran3005]

can it work with stm32f303 ?

[@omeranar-youtube]

how can i change/modify variable's values while code runinng ?

[@ControllersTech]

You can't modify variable while the code is running.. after modifying them, you need to compile and then run again..

[@omeranar-youtube]

@@ControllersTech but "keil ide" allows this, right ?

[@ControllersTech]

I don't know about keil.. maybe it does..

[@envicto5948]

how do i do the same in putty

[@ControllersTech]

What exactly ? The output is irrelevant of what software you are using on computer.

[@arashhashemi7091]

Thanks so much 💞

[@alihancoban]

where is the ITM sendchar

[@ControllersTech]

Check the pinned comment.

[@alihancoban]

@@ControllersTech how can I use in C++

[@vahidrezashokouh1139]

how abou iar ?

[@tuloca011]

i love you

[@slavaglow6933]

Can I do it with my board STM32F4 Discovery?

[@ControllersTech]

Yes you can..

[@Seff2]

Wtf... why does a printf command has to be so needlessly complicated? In arduino or mbed you just write printf(...) and done. With stupid CubeIDE Shit you need a doctors degree to get a simple output... just ridiculous. Who can use that or create anything more complicated than a blink sketch? Speaking of which: A fucking blink sketch generated in cubeF(uck)X for my discovery board gives me a 700!!!! lines main.c file. WTF?!? 700 lines to to toggle an LED on and off???

[@ControllersTech]

2 things 1. If you don't like cubemx generated code, why don't you use the registers ? This way you only write the things you need 2. This printf shown in the video prints the message on debugger console. In case of arduino, that message prints on serial console. Even you can define a printf function, where you can easily send data to serial console using uart.

[@Seff2]

@@ControllersTech The registers are even worse. Using the HAL is already way to complicated for me, using registers would be insanity. Then i could basically just start using Assembler right away...