For sure you have v3.1 hardware? The reason I ask is because there’s a different IMU in v3.0 vs v3.1
Double check what you have and make sure you have the relevant firmware installed. If the issue still persists, then feel free to PM me.
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assuming the label on the box is correct 
@shaman — sorry, it looks like I’m not allowed to PM just yet, nor edit my posts it seems, apologies for over-replying. so, the box cover says 3.1, VESCTool 6.newest was reporting “old but mostly compatible” prior to FW upgrade (FW was a 5.03, and I’m pretty confident I saw FOCer_V3_1 in HW string). IMU was certainly working prior to the upgrade. I’ve already tried downgrading to 6.00 — same story. I’m willing to try going back to 5.03 but I see two binaries in …/vedderb/vesc_fw_archive/tree/main/5.03)/Little_FOCer/ (default and default_no_hw_limits) — not sure which one I should try based on my hw and whether it’s safe to try both without risking to brick or fry anything. also, suppose I was trying to wipe out everything and start from a clean slate, what is the best way to do it? does FW reinstall achieve this?
thanks!
This is the code difference that might be messing you up
If you look at the PCB and find the IMU, you might be able to figure out which version you have and load the right firmware.
I believe this is the IMU, right next to the STM32
LSM6DS3 should look something like this with a QR code of sorts
BMI160 should look something like this
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thanks so much! that was just the bit i needed. turns out, MakersPEV sent me a mislabeled box: the cover says 3.1, while it’s a 3.0 on the inside. not cool, not cool — could’ve at least attached a sticker that says as much. 
but now i know, and the IMU seems to be fine. thanks again! 
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Hey glad it got sorted out! Yeah looks like my first suspicion was correct. You just needed the proper firmware to match the hardware. Sorry about the mislabeling on the box
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hey, no problem! thanks a lot, this was super helpful, and i’m almost done with the build now.
if you don’t mind another noob question, i’ve seen a lot of different howtos on tuning the boards, but they all seem to be omitting one important thing, how (or rather where) to set safe initial values for first testing. i’ve just tried supposed “reasonable” app defaults for a split second on my custom onewheel build, and that left tire marks on my floor — there’s no way I’m getting on this board as it is now!
so i clearly need to nerf it, and nerf it hard, until i sort it out — what’s the best way to do it? ERPM limit? Motor Amps limit?
and if i’ve missed some FAQ, i bet other ppl reading this later will appreciate a link as well.
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I’m assuming your using the LFOC in a onewheel type application. If so, I’m not an expert on this. But thankfully there are experts out there who can help. If you bought from makerspev or customwheel, then they can help get you set up. Otherwise, the site below has a bunch of good info.
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well shit my little focer v3 stopped working mysteriously. i was riding then stopped at a traffic light then it just went lights out. no lights and no voltage on the 5v and 3.3v rail. I assume the buck converter is dead.
i would like to fix it but I can’t seem to identify some part numbers to investigate the idea of replacing some ic’s
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this IC next to the power switch port the side of the PCB gets warm and so does the inductor underneath.
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If it died during regen breaking, then the voltage spike from the motor may have damaged the protection circuitry to the buck converter. The buck converter itself may be ok.
What’s your battery setup? Does it run a BMS? We’re you using aggressive regen limits? Feel free to take this to PM where I can help you troubleshoot
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Does anybody know what ohm rating the two resistors labeled 76X next to the CanBus should be? I blew the Can chip and suspect one of these are damaged as they do not read the same. My understanding is the Hi and Low should terminate with a 120 ohm resistor but that’s not what I’m getting on either. I can’t post images yet but someone posted an image that shows them earlier if reference is needed.
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Both of these resistors are “seen” in series by the CAN bus and should both add up to close to 120ohm. Each resistor should independently read 60.4ohm since that’s the most common and available value to achieve a total close to 120ohm.
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HI! First post here.
Just went for the first test ride after upgrading to the little focer from a flipsky 75100, all working well except for the motor temp sensor. It reads fine and accurately when I’m stationary but as soon as I give some throttle the temp can jump upp by 20-30 deg or down by the same amount. I can even see negative values when using regenerative braking… The temp sensor worked fine on my old 75100.
Anybody have an idea of what could be wrong?
Tried including a screenshot but apparently new users aren’t allowed to.
Are your motor temp sensor wires bundled with the motor phase wires?
Sounds like induced signal noise from the high current in the phase wires.
Try a test, temporarily route a new temp sensor wire as far as practical from any high current wires,
go for a ride and see if there is any difference.
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Yes, the motor did not originally have a temp sensor. I aded a 10k thermistor directly to the motor windings and routed a single cable a long side the phase and hall wires. I used the same ground as the hall sensors. I will start with connecting an external thermistor and se how that behaves.
Thanks for your help!
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Check your motor thermistor beta value make sure it matches the value of the thermistor you installed
Hi @shaman
My friend and me bought couple of Little Focers over customwheel.shop. Sadly they don’t reply us. We send 3 broken Focers to Amsterdam (nearly 6 months ago) and the last we heard was “we can’t exchange them and have to send them to the USA” since they don’t reply or anything else…we wrote like +10 emails and don’t get an answer…maybe they send it to you?
Let me see what’s going on. Feel free to take this to PM
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Hey @shaman
I set up a new Lil Foccer 3.1 today.
Pretty standard XR conversion, stock BMS Bypassed, and a CBXR.
Set up seemed normal and everything looked good.
After working for about 30 seconds it started push back, and I looked at the app and it said 80v .
It’s a 15S CBXR that is at 54 volts.
Also if I shut it down it won’t turn back on until I unplug the battery.
The xt60 is reading 54v, but the Foccer is reading 80v.
I have reflashed the firmware, and it doesn’t seem to change the behavior.
Is there Any other troubleshooting I can try?
This is the very mayden voyage.
Thank you for your time and assistance.
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