unable to get into bootloader on stm32f103

[developer2]

Posted on May 31, 2013 at 08:59

Hi,

i bought 2 chips STM32F103RET6 , i put them into boards, one chip is working normally , so it's possible to flash it via USART1, but second one is not reacting on USART1 for new flash, and i think that it's not reacting also on nRST button, could you help me ? is it possible to restore bootloader ? i don't know what else it could be ... i don't have programmer st-link, but i have FTDI with jtag, is it possible / working to get it running using FTDI's JTAG ? Kind regards,

[Tesla DeLorean]

Posted on May 31, 2013 at 13:31

Well that is suggestive of an issue with soldering, or power. If the system loader doesn't come up when BOOT0 is high, I seriously doubt that JTAG will function either. Check initial conditions, and pin voltages.

You can do a test of the system loader by using a serial port in 9600 8E1 and sending an 0x7F character. You should see and 0x79 in response. If not the board is going no where. The system load is in ROM, it's not going to need restoring Does the FDTI JTAG come with any working drivers, and utilities? If not you need to invest in some decent tools.

[developer2]

Posted on May 31, 2013 at 15:33

i see some strange behaviour: when i plug-in power, i have on PB10 and PB11 at first moment level zero, and after 1.5 seconds i have level one, i don't have each pin connected to leds but those two are ,

and port USART1 is unconnected from voltage levels point of view, OSC_IN and OSC_OUT without voltage, is it possible that there is some kind of under-clocking ? so the device is so slow and i see it like not functional ? Kind regards,

[Tesla DeLorean]

Posted on May 31, 2013 at 15:55

Problems are almost always about the board and connectivity. Power and resets being the most critical. It's pretty much on you to figure out what's attached, and if it's done properly.

The part does not use external clocks until they are enabled. The part with start by running the 8 MHz HSI clock. The analogue supply handles the POR circuit, so needs to be present. Connect VBAT to the supply absent another connection. Do not drive high signals into NRST

[developer2]

Posted on May 31, 2013 at 16:28

i found it,

i had disconnected Vdda due to determine the right resistor for voltage reference, because in near future i want to measure using AIN inputs, and i din't know that Vdda is supplying PLL :( so i pushed determination of resistor , and now i have 2.5V on Vdda , and bootloader is replying, thank You very much Clive, Kind regards,