What is the signalling level of the uart TX/RX?

[wt]

I'm assuming it's 5v signalling. I just didn't see it in the hardware connection docs.

[bphillips09]

@wt I don't remember concretely, but all of my UART adapters have been set to 3.3V the entire time I've been working with them. I can double-check the voltage on the line later and confirm though.

[wt]

If 3.3V works, just document that and maybe note that higher signalling levels have not been attempted?

[MrChromebox]

@wt both 3.3v and 5v signaling work fine AFAICT

edit: I should double check, the jumper on my board might just be for Vcc and not change the logic level for TX/RX
edit2: it changes both, so the tuner seems 5v tolerant, at least for short periods of time

[wt]

Anyone have a head unit they could measure while using the dongle?

[MrChromebox]

Anyone have a head unit they could measure while using the dongle?

what exactly do you want measured? I'm testing on an Android-based HU on my test bench currently

[wt]

what exactly do you want measured?

Oh, I was wondering what signal level third-party head units send to the dongle. I don't have a head unit that uses the dongle.

[MrChromebox]

Oh, I was wondering what signal level third-party head units send to the dongle. I don't have a head unit that uses the dongle.

the HU doesn't connect to the tuner directly, it connects via the FT232 (or similar) USB/serial interface. The HU-side connection is standard USB, and the FT232 determines the signaling level from itself to the SXV300

[bphillips09]

Oh, I was wondering what signal level third-party head units send to the dongle. I don't have a head unit that uses the dongle.

the HU doesn't connect to the tuner directly, it connects via the FT232 (or similar) USB/serial interface. The HU-side connection is standard USB, and the FT232 determines the signaling level from itself to the SXV300

I think they mean an aftermarket head unit that connects to it directly via UART, i.e. Pioneer/Kenwood/etc.

I don't have one to test with currently but maybe someone else does.