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Visitor II
October 16, 2019
Solved

STM32f103vdt6 design

  • October 16, 2019
  • 6 replies
  • 3571 views

Hello!

I have designed a custom board, i have attached the schematic of it. My problem is that I have an ST-link v2 and i cant connect to it, i get target not found. Is my schematic correct or I have missed something? I have power and ground on all necessary pins on my board. I connected VDD, GND, SWDIO and SWCLK to my board from the ST-link, I used pins 1, 7, 9, 20. I tried to swap the pins of the data and clock signals, and all the settings in the ST-Link utility. My programmers firmware is up to date.

Best regards,

Attila

    This topic has been closed for replies.
    Best answer by TDK

    That chip is upside down.

    With the text right side up, pin 1 is at the bottom left on the chip.

    Agreed, it's confusing with two marks.

    6 replies

    Graduate II
    October 16, 2019

    Check the voltages

    Check part orientation

    Check level on NRST pin

    With BOOT0 pulled high try talking to the ROM based System Loader, via USART1 PA9/PA10, at 9600 8E1 send an 0x7F data byte, and check for response. Use something like RealTerm which can send hex bytes.

    Graduate II
    October 17, 2019

    Orientation FTW, I just need to redeem my points

    Super User
    October 16, 2019

    VBAT should be connected to VCC.

    Is pin 73 really NC on the package? Seems odd.

    AGERE.192Author
    Visitor II
    October 16, 2019

    I tried that too, with no luck. If Im correct it is NC, I attach the datasheet.0690X00000AqRyHQAV.jpg

    AGERE.192Author
    Visitor II
    October 16, 2019

    0690X00000AqRmLQAV.jpg

    I have checked the voltages, all ok. The part oriantation indentation is in the up right corner. For some reason the NRST is 0.26V, but if I put a wire I can bring it up to 3.2V. But still no luck. I tried with an arduino the BOOT0 method with 0x7F data byte. I checked the answer on the oscilloscope and there was some response data.

    Super User
    October 16, 2019

    If NRST wants to be 0.26V, voltages are not okay. Indicates a problem in your power supply scheme somewhere.

    AGERE.192Author
    Visitor II
    October 16, 2019

    This is akward for me too, and the second odd thing is that PA2 is shorted to VDD in the interior of the IC. But I measured the voltages on all the pins and are ok.

    Graduate II
    October 16, 2019

    Definately sounds like you've got the device rotated.

    NRST will be low absent a VDDA supply on the correct pin.

    Show clear, in focus, high resolution photo of the chip on the board.

    Don't confuse the mold ejector marks for pin 1 designation

    AGERE.192Author
    Visitor II
    October 16, 2019

    I think this is the case, I attach a picture. But I think that I confused it. I hate these on concrete situations, in the datasheet I have seen only one circle on the top of the IC. And on mine there are 2.0690X00000AqSorQAF.jpg

    Super User
    October 16, 2019

    Did you measure *directly* on the pins? I am aiming at bad solder joints.

    Did you measure also VDDA/VSSA?

    Is the text on the chip bottom-up?

    JW

    AGERE.192Author
    Visitor II
    October 16, 2019

    Yeah. I have thinked about this, and I measured all the voltages on the top of the pins, near the package with really thin probes. I measured all of the vdd/vss pins. No, the text is up-buttom.