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Cannot connect to new STM32F3 Target

kc10kevin
Associate II
Posted on December 24, 2015 at 06:25

Hi All,

I’m having a problem that I hope folks might be able to assist with.

 

I have built 100s of STM32F1 target based multirotor flight controllers.

 

Never once have I had a problem programming the F1.

 

Decided to make an F3 version of the flight controller.

  

I basically reverse engineered this flight controller:

http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=76_156&products_id=4221

So, I made a F3 breakout board with just the basics on board for prototyping purposes.

 

Put it all together and have now spent days trying to get the F3 to connect so I can flash it.

 

Problem:

 

I cannot connect to brand new STM32F3 targets via SWD no matter what I do.

 

Using ST-Link and DiscoF3 I cannot get it to recognize the F3.

  

When I click on Settings, it shows “Detection Fail�? and will not connect.

 

I’ve double/triple checked all connections and orientation are correct.

 

- NRST has 10k pull-up to 3.3v.

 

Shows 3.3v on power up.

- Caps all around per typical setup

- VBat/Vdd at 3.3v

- Vss all grounded

- No Shorts

- DiscoF3 jumpers pulled for SWD

- 10k pulldown on Boot0

I decided to take an F3 and put it on one of my F1 target boards (barebones) and still will not connect.

 

Things I’ve done/checked:

  1. Tried 3 different brand new F3s on 3 different boards.   2 of my breakout boards and 1 of my f1 target boards (barebones).
  2. Checked to make sure all connections and orientation is correct. 
  3. Ran each pin individually to make sure no shorts. 
  4. DiscoF3 works perfect.  Can connect to F1 and other F3 targets with no problem.  Connects just fine to the F3 target Flight controller in the hyperlink above.
  5. Tried to connect via UART/Serial o PA9/10.  No joy. 
  6. I’ve pulled Boot0 high. No Joy.
  7. Tried to send 0x7E via serial, no response.  
  8. SWD Connections are short and I'm 100% sure they are correct.  No problem with F1 or existing F3 targets.  Just when I try to connect to a brand new F3 via breakout board or F1 board (with new F3).

I’m out of ideas and ready to throw in the towel.

  No way all three F3s I've tried were defective.   I'm sure I'm just missing something simple.  

Hopefully someone can point me in the right direction.

Thanks in advance for the help.

STM32F3 breakout board I threw together:

0690X00000605KAQAY.png
5 REPLIES 5
Posted on December 24, 2015 at 07:36

So I don't have to reverse engineer it, perhaps you have a netlist or schematic?

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kc10kevin
Associate II
Posted on December 24, 2015 at 08:53

Thanks Clive for the response.

I didn't do a schematic for the breakout board. Just threw it together. Sorry.

I've attached the schematic for the F1 board that I put an F3 on.

Only populated the board with the following:

F3 vs F1

U2 Circuit to get power to F3

Vdd Caps the same

8Mhz Resonator with integrated Caps (33pf, Murata CSTCE8M00G55) vs separate crystal/caps/1M Res.

Boot0 Circuit (JP7)

D5 and D2 LED circuits

* no pull up on NRST in this schematic

Just realized I didn't add the U6 circuit (XOR inverter) on UART1. So wont get the serial to work on that until I add it. Gonna try UART3 instead in the morning.

________________

Attachments :

CopterControl_3D_Schematic.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I1Ki&d=%2Fa%2F0X0000000blS%2F6q1qYdSW8K7IsOHEDLqytP_JJWoc.uEfhJQNRAsvzSE&asPdf=false
kc10kevin
Associate II
Posted on December 25, 2015 at 06:14

Small Update:

Put a USB on the board.   Jumped Boot pins.  Was able to connect to STM Bootloader via USB and flash F3.  Still cannot connect via SWD/UART no matter what I do. 

Any help/input would be greatly appreciated.

song
Associate II
Posted on December 29, 2015 at 05:47

When you used CSTCE8M00G55, did you pay attention to the mounting direction? If the direction is not correct, the resonator may not work properly.

Posted on December 29, 2015 at 06:19

This shouldn't preclude the part connecting via SWD, the STM32 doesn't start external oscillators automatically.

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