On Thu, Sep 19, 2019 at 02:43 AM, <hugen@...> wrote:
I am discussing with the AA6KL9 to build a new firmware using the
STM32F303CCT6. If all goes well, it can be provided later. To replace the mcu
directly on the current hardware, you need to add a 1.5K resistor to the VCC
on the USBDP Pin. The DFU mode of the STM32F303 requires an external 8M
crystal to use USB, but STM32F072 does not need it, so you need to use SWD to
update the firmware. You need to prepare an ST-Link or DAP-Link.
BTW: The new STM32F072-based NanoVNA firmware already supports TDR.
Thank you!
ok, 8M crystal is normally not a problem for me, but for most nanovna owners F303 is then not real 1:1 replacement. We should probably, if we need more memory, stick on crystal-less USB STM32 (AN4879) , with pullup support, with DFU support (AN3155), LQFP48 package and ChibiOS support. Afaik STM32L433CCT6 should be good replacement, only pullup for USB necessary, and some ADC / clock / I2S changes to code, but it does need newer ChibiOS, which then does not compile with nanovna. Anyway, for myself i will probably solder crystal and use F303 (ADC/clock changes necessary), if i not manage to fix newer ChibiOS compile Errors with STM32L4x series.
tinhead
