GD32 MCU support

[sakisdog]

The last 2 days i have been experimenting with a dead OMNIBUS F4 V3 flight controller. The STM32F405 chip was shorted between VDD and VSS so i ordered a STM replacement and a GigaDevice replacement (GD32F405RGT6).
The GD32 chip is pin-to-pin identical to STM32F405 with the only difference on 2 pins that the STM have connected 2 caps.
I soldered the GD32F405 on the dead flight controller and after confirming that the short is gone i power it up with the boot button pressed. And...surprise! The GD32 DFU device appeared in my device list.
I installed the WinUSB drivers through Zadig but Inav configurator could not "see" the device. I changed the PID and VID of usbDevices inside the inav configurator with the correct ones and finally i was able to flash the flight controller.
The flight controller seems to boot up normally with the blue led blinking fast many times during the startup and then blinking with a slow rate.
The problem is that i cannot see the controller in my device list. When i connect it with usb nothing happens. No plug-in sound from windows, no device in device manager. Nothing. It just sits there.
After searching a lot in chinese forums i concluded that it is a firmware problem. So now i'm trying to find what parts of code i should change for the usb to work.
Anyone have any clues?

[babitsyn]

I use GDAllInOneProrammer to flash GD32F103CBT6 installed in CC3D with inav 1.7.3, and it works well. I think it's good idea to return support fo F3 targets due to GigaDevices offers pin-to-pin compatible chip GD32F303CGT6 in LQFP-48 package with 256kB program memory and 768 kB data memory onboard operated at 120 MHz clock. It would be cheap replacement for stm32F103 and will revive CC3D boards.

[sakisdog]

I don't know about F3 chips but i had no luck with F4 and iNav. The only logical thing that i didn't try was to use the GigaDevice's Firmware Library with iNav but that requires that i have to import all the necessary files into iNav.
I compared all the offset addresses between STM32F4 and GD32F4 and i couldn't find a difference. I can not figure out why the HAL library of ST isn't compatible with GD.

[babitsyn]

You should try this sequence:

1. Press boot-key
2. Connect via usb-ttl adapter to UART1
3. Run GD All-in-one-Programmer
4. Erase whole chip
5. Flash it.
6. Release boot-key. Run normally.
   Do not use Inav-configurator to flash GD, every time which I did it - GD32 never started correctly.

[ujara]

I do use the GD All-in-one-Programmer and followed what you had indicated but did not change the outcome.

[babitsyn]

I have soldered on an F3 board with a GD32F303CCTX (it had a STM chip earlier). Any clues how to get it working with USB and 120Mhz? with INAV? I am trying to follow the thread above. I have modified the following files:

1. stm32f30x_rcc.h

2. stm32f30x_rcc.c

3. system_stm32f30x.c

4. hw_config.c
   Were there any other changes required? I did try and look around for hard coded 72Mhz or 8 Mhz HSE cystal instance but seems i have covered it all. What I am not sure about are:
   for GD32f303 can I use #ifndef STM32F30X_CL ? or is it something else?
   Secondly for the changes in stm32f30x_rcc.h do I have to modify

#define IS_RCC_USBCLK_SOURCE(SOURCE) (((SOURCE) == RCC_USBCLKSource_PLLCLK_1Div5) || ((SOURCE) == RCC_USBCLKSource_PLLCLK_Div1)) To account for 120Mhz? // Full speed

Last was the PLLMULL settings in system_stm32F30x.c where they as follows: // Full speed if (HSE_VALUE == 12000000) { RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_PREDIV1 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL15); } else { RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_PREDIV1 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL9); } I guess I am not that great at coding and trying to guess some of it so your input is helpful..

You did not set second bit of USB multiplier, please read previous messages. And check frequency of you crystal - 8 MHz or 12 MHz.
RCC_CFGR_PLLMULL15 and HSE=12 MHz will set cpuclock to 180 MHz, it's wrong. For HSE=12 MHz PLLMUL should be 10.

[DaLLuZZ]

Maybe this will help you solve the problem with gigadevice f4 chips
https://forum.chibios.org/viewtopic.php?t=6008
https://forum.chibios.org/viewtopic.php?t=5758

[DzikuVx]

Inav will not bring back F1 or F3 support

[MicroMontis]

F1 and F3 are the past. Let's not look to the past. But what about the supporting of the GD32 F405 from GigaDevices ? Would you consider looking into this? Or should we just stick with STM?