Connecting an SP3 OSD with softserial at 19200 baud - Can I flash the OSD?

I’ve swapped the VTX in my original Crusader from an SP1 to an SP3. The original crusader runs on a naze32 and I’m using a spektrum serial receiver so uart2 is permanently occupied. I could use uart1 and unplug when I want to plug the USB into the naze but I would prefer to use one of the softserial ports at 19200 baud.

I think I will need to re-flash the SP3 OSD to change the baud rate but I’ve not found any discussions about this online. So, three questions:

Has anyone tried to flash the SP3 OSD?

Can it be done over the USB interface or would I need to run an FTDI adapter into serial leads?

Will the OSD run OK over a 19200 serial link?

Many thanks.

Dave P

Hi Dave @Dave_Patterson

It’s been a few months since I used soft-serial on a NAZE32 but I think you can change the speed of soft-serial ports in the ‘ports’ tab, selectthe usage required and then the speed from the drop-down list

Steve :slight_smile:

Thanks Steve. I read somewhere that driving softserial at higher baud rates was a strain on the processor so the advice was to pull it down. (I’m now googling and I can’t find that advice so I could have got my wires crossed.)

I guess I can try it to see how it get on. I could just fork out for an f3 board for the extra uart. Still, seems like it should be possible to flash the osd. I could try that too. What’s the worst that could happen?.. :slight_smile:



Quick update on this: I just flashed the OSD with a fresh copy of MWOSD 1.6. The only thing I changed was the baud rate which I pulled down to 19200. I was able to flash over the USB port from arduino IDE. Very simple.

I then paired it with a softserial port on the naze32 running at the same rate and I get modes, horizon, stopwatch and battery voltage. The voltage looks a bit off but other than that I think it’s everything I want. No drama. :slight_smile:

To answer my own post:

  1. Yes.
  2. USB works fine.
  3. 19200 appears to work fine too.

That’s great Dave @Dave_Patterson
Glad you got it all sorted
Happy flying
Steve :slight_smile: