The main issue with this port is that it uses a different (and fixed) baudrate than the other uart port. Changing this value require rebuilding the firmware. @Nick_Leet3D rebuilt one with the correct baudrate for the Davega here : Unity internal UART wiring
I didn’t try to update my unity yet with it, so please share your results if you try it 
2 Likes
IO and CLK are for SWD programming of the BT module. So others would call them SWDIO and SWCLK and they have nothing to do with SPI.
But you are right that only RX/TX/3.3V/GND are needed for UART. You can just leave IO and CLK unconnected @Clunt.
1 Like
I remember someone was asking about the wiring for the unity BLE module, so they can use that port for something else, or maybe my memory is a bit fucked due to working during holiday 
Yep, that was me, in the post i shared just above
1 Like
What baud rate is it fixed to by default?
i think
2 Likes
I wasn’t sure of the best place to post this. So I am trying here.
I have a Unity I bought when the raptor shop first showed up.
One side has some sort of issue.
Can’t remember what it was exactly…
But one side is bad…
Question is.
Can I set this up to use as a single esc using the vesc tool?
I am wanting to use the good side to run a single drive board.
i don’t think u need to setup anything, just don’t connect anything to the bad side, it should work like a single drive esc.
rememeber to tape up the extra wires and stuff, u don’t want anything shorting those phase wires.
5 Likes
So,
I have not ran the Unity with just one motor…
but I did try to run detection, with just one motor plugged, in.
and it still pulled values(weird and low) for the side I had not plugged anything in.
So I worry if i don;t do anything the unity will still try to push power to the empty wires.
i have no idea if this is possible, or an actual issue, beucause i am dumb when it comes to electronics.
i also figured there would be a way to turn one side off on the vesc tool…
1 Like
i don’t think its doable to just disable one side of unity, since its a single mcu esc (or maybe im wrong)
if its me doing this, i would tune down everything and try to ride slowly with one motor, log some data and see if there is anything weird going on before full blasting it, but that’s just my way of doing things
sorry i don’t think i can help further 
1 Like
First test run on a brand new Unity (bless me fathers, for I have sinned) and I get a f cking DRV fault. I wasn’t going fast at the time thankfully. I was pulling some accel/brake to re-check my config when the power cut out suddenly. The Metr figures look pretty tame when it actually happened but the Fault details are throwing some weird numbers for motor 2. I’d really appreciate any insights into why it happened or what I can do about it.
I’d say the weirdest thing in this fault is the battery voltage… do you have a BMS hooked up in the discharge path or bypassed? Dipping from 42V to 21V is pretty extreme, seems like the battery is becoming disconnected somehow.
@Deodand
Some strange % voltage sag happened during last ride (but the actual voltage graph looks ok to me)
No throttle for about 0.5-1 sec
Happened only once since 2.500km on that board but twice during that ride (the second one without that strange “no throttle” issue)
Any ideas? Thank you in advance 
Upload the actual metr data please not screenshots please.
Some sag is to be expected. Keep in mind the actual ESC is sampling at 10 kHz while this plot is only at like 20 Hz, so it is very possible to miss data in the graph that will be reported on the fault data. Impossible to tell why you would experience a cutout without the data from the ride where is happened.
Goddamn. I didn’t notice that. The voltage drop doesn’t show up at all on the Metr trace so it must’ve been very fleeting. I see that the Metr voltage measure is smoothed but a fluctuation of that size is too rough to be smoothed.
Yes, there is a BMS in the discharge path. I wonder why it would cut out there though. It wasn’t a high draw or anything. I was on smooth terrain so it’s probably not vibration-related. Hmm… the plot thickens.
Thanks for the insight, @Deodand. Really appreciate the pointer.
I’d recommend bypassing the bms for discharge and seeing if you get any future cutouts.
1 Like
So after a full overhaul and a few hard test runs around here, I drive out to some cool trails about an hour from me and this happens:
Battery voltage drops off a cliff. Duty cycle hits 114%(!?). Lights are on but nothing’s happening. I wasn’t pushing it hard at all. Wasn’t hitting crazy rough terrain. Metr tells me I’ve got about 7v coming in. BMS app tells me I’ve got 50v going out.
Anyway, I drag the thing back to the car. Drive back home and strip it down to see what’s up. Everything looks intact. No soot. No exploded components. Everything looks mint. I can measure 50v coming in on the main power lines at the PCB. I checked the momentary switch just in case but it’s fine. The second fucking Unity within a few small km’s is ded.
Notice also at 13:13:14.015 there’s a voltage blip there as well.
I’m guessing that this isn’t symptomatic of the usual anti-spark death issue.
Paging @Deodand, @Fatglottis, @seaborder: Is there anything I can do to further troubleshoot this?
I swear to God, I’m losing faith in this shit.
1 Like
This looks like a loss of battery voltage.
Are you discharging through the BMS?
Do you have photos of your battery insides?
Check for broken battery series connections.
Do you have an XT90 that’s vibrated apart? Are they all tied with twine or cable ties so they cannot disconnect?
1 Like
I can do all of this but the fact remains: 48v is reaching the Unity PCB but it’s not turning on. It was reporting 7v when it was seen to be getting 48v.
2 Likes
