Non-formated data on 3DR radios

I need to send data, that isn’t typical RS232 formatted with the start bit, stop bits or any of that. It’s formatted, but not compatible to a typical USART:slight_smile:

The radio does what I need in every other way. Since the radios are transparant, I was hoping that ti USART could be bypassed, using the DF-13 connector.

I’m using TTL levels, but trying to send 50,000 bits per second doesn’t work. Something shows on the RX of the other receiver, but it’s garbage. Looks slower as well.

I haven’t been able to find a schematic.

I think if it’s not using the regular start bit / stop bit serial protocol then it would require a software change down at the HAL (hardware abstraction layer) to add support. A better solution may be to try and find a hardware converter from this other serial format to the regular one.

I’ve moved this into the Radios category because when specified as “Blog” it appears on the front page of

Thanks Randy. It’s been a while since I’ve been around.

I’ll see if it’s possible to work up a converter.

At the HAL level I guess one would have to replace the USART config? I haven’t found a schematic of the modem so I’m not clear on the architecture.

Had a quick look at the firmware. I have the architecture clearer now. It’s giving me some ideas on how to get my data through, as long as I don’t run into hidden timing problems.

UARTs have a start bit for a reason, what is your purpose for removing it? Sounds like you just want a pulse train generator

Right. A pulse train with its own sync mechanisms and codification protocol.

For now my “translator” might work. I’m taking the pulse-train and converting it to bytes then sending it out the serial port. At the other end I reverse.

We’ll see how it goes. If that doesn’t work, I’ll have to look at mods to the radio’s.

In any case, internally the radio’s would have to convert to bytes to send the to the SiK So I may as well do it outside the radio’s.

perhaps a better method is to use a digital motor signal like DShot?