Damn! Not sure how I missed the internal SWD, I looked over pics I took of the PCB when In had it open but didn’t even see any pads broken out. Its there all along with a JST PH header :: Would have made flashing an Nrf52 BT module much easier. Took me several hours trying to find my ST-Link tool. ::
Have you tried the 100_250 FW yet?
What are the symptoms you experience? Im getting a weird bug if Im connected to a PC with VESC tool via USB. My com port is immediately disconnected if I draw any current from the motor, even the FOC wizard will knock me off. Frustrating as hell and it didn’t do this when I first got it.
With my 4.20 and 6.6 I notice when motor spins erratically even when the input on the remote is constant. When reconnected to vesc tool I cannot change any value nor run the setup wizard unless I reupload the firmware.
My 75100 are still fine… atm.
That will load on there, but thankfully I didn’t try to run a motor with it. This 75100 uses different resistor values for the voltage dividers, and a different number of shunts in parallel. I’m sure I would have fried something if I tried.
I’ll post what I have so far later tonight. It’s probably just the GPIO pins that won’t work right The unit is being abused on a friend’s ebike right now so firmware testing is paused.
I also want to add the solder that you suggested and silicone/epoxy those caps down before long term use.
This is the default firmware I pulled from the device using an ST-Link. I was able to reload it and run the unit successfully after flashing a different firmware on it. Can be used as a backup firmware when testing.
Flipsky_FOC_75100.bin
.h and .c files I’ve created for the 75100. UNTESTED. MAY DAMAGE ESC. I think I configured everything correctly but I won’t be able to test it until I get the FOC 75100 back to play with. All changes are noted in the .h file’s comments. Need default ABS MAX current and MAX VOLTAGE values, but not critical for bench testing.
hw_75_100.c
hw_75_100.h
Plan to test this firmware:
Open to suggestions / feedback
Good news, everyone!
The firmware update works!
EDIT: Created a separate post here:
Well done! This deserves to live in the Citadel section so many can benefit.
Here are some logs of my first tests
I bought the single 75100 ESC (pic below) before this came out. Really considered getting it, but there is one thing the old ESC has: a 12v socket.
Still very tempting though…
Any recommendations how to turn this off when not in used? I wanted to use a button but afaik it needs an anti spark switch which is difficult to get for a 20s li ion (84v FC)
Flipsky also has a 20s compatible antispark
Based from the specs:
Would that mean I’m gambling whenever I’m at full charge (84v) since it says it safe for 80V but rated for 90v? 
Nah. It’ll work. A bunch of members here have had no problem.
I think it’s relatively few of us (I have had no problems but I’m at very low voltages) and at least one person had it detonate on first or second use
Edit: This is the example I mentioned
Cc @newbiee
Oh shit I didn’t see that. I thought it was working for him
Yikes. I have a 20s8p P42A pack and the guy you mentioned has 20s7p. Kinda scary. Any other suggestions for turning it off? Or loop key is the way?
So I think the p groups shouldn’t be a huge issue, there’s two rough ways to kill one of these. 1 is sustained load, and unless you’re using the big pack to get quite high constant currents this might not be an issue at all. I’m mentioning it because it depends more on the use case than the battery. Mooch has some nice detailed info on this specific device here, might help or it might be a bit over the top
Number 2 is inrush current (the thing that usually causes a spark) and that is largely dictated by the size of the capacitors in the ESC I think, plus the modenof operation of whatever antispark solution you use. Not sure how technical you care to get, but the short version is an uncharged capacitor acts loosely like a short circuit momentarily because it can take crazy high currents at the start of charging it up and the current quickly drops towards zero as it approaches full charge of. ESCs have a fairly big capacitance that need to be charged up, so if your antispark is designed well to slow charge these capacitors you’re fine. Unfortunately I don’t have any great insight here, mooch made a comment in point 8 of the post I linked above about how there’s no obvious red flags in this device but he also hasn’t got a huge amount to comment on.
I have it on 20S4P but didn’t abuse it so far. Seams to be pretty solid though. But yeah it’s FS…
I run the 75100 without AS and use an ANT BMS instead to turn it on and off.
Which current rating ant did you get to be able to run it in the discharge path, do you remember how much you paid for it, and how’s the experience with the app been? I’ve found them really interesting but haven’t seen many people here using them
I swapped to just unplugging it all through my qs10 connectors after it blew because it failed open… Then my esc blew because of too many amps lol, so waiting on replacements