Initialize uart first, then enable interrupt

ligenxxxx commented 1 month ago

This PR is used to solve the OSD freeze problem after VTX is powered on.

Cause:
- The initial baud rate of VTX is 230400 and that of FC is 115200.
- After power-on, CPU_init() will initialize the uart to 115200 and immediately enable interrupt.
- VTX executes Init_HW(). During this period, the serial port receives some msp packages (115200) from FC.
- VTX sets the baud rate to 230400(eeprom saved) at the end of Init_HW().
- VTX enters the while(1) loop and parses the complete msp package, mistakenly thinking that the baud rate of FC is 230400.
- After that, VTX can no longer receive the correct msp package due to the baud rate mismatch.
Solution:
- Do not enable interrupts during CPU_init().
- Initialize the uart bardate(eepram saved) earlier to avoid losing data. Then enable interrupt.

sugaarK commented 1 month ago

tested on brand new whoop lite that was having issue that only increasing the uarts baud rate to 230400

this pr totally fixes the issue

nerdCopter commented 4 weeks ago

does this fix the broken layout or something else?

i.e. this or no?

sugaarK commented 4 weeks ago

does this fix the broken layout or something else?

i.e. this or no?

It’s more than a broken logo the baud rate for msp ain’t correct

ligenxxxx commented 3 weeks ago

does this fix the broken layout or something else?

i.e. this or no?

If you cannot enter the vtx menu, this may be a compatibility issue between the VTX uart and the FC uart, or the VTX uart tx may be damaged. You can try other types of FC or other uarts connected to the FC.

hd-zero / hdzero-vtx

Initialize uart first, then enable interrupt #213