Pulled the 3.3V and no change. When the regulator is intact, it is only getting ~1.3V input, and outputting around .8V. Does this mean that my DRV is bad, since I think? that supplies 5V?
Can you check the input voltage to your DRV and ideally the 5V output pin too? Assuming the input voltage is good and the 5V output is bad, you might need to lift the 5V output pin and try it again. It could have a partial short downstream.
DRV8301 datasheet here: https://www.ti.com/lit/ds/symlink/drv8301.pdf?ts=1602887988201&ref_url=https%3A%2F%2Fwww.ti.com%2Fproduct%2FDRV8301
Measured 36V at both PVDD1 and PVDD2, with nothing registering on AVDD. Then lifted AVDD and still no voltage with a measured 36V on the input.
Looking at the DRV8301 spec sheet and the CFOC2 V1.0 schematic, I think you want to look at the “PH” pins (pins 50 and 51). I think that’s where the 3.3V regulator is getting its 5V.
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Oops, my bad. With the PH pins still connected I measured around 3.2V with a 36V input. With the pins disconnected I measured ~35V with a 36V input.
When you lift the PH pins from the board you’re reading 35V output? Some buck converters seem to need a small load to give a proper reading. I’d be tempted to connect the PH pins to ground through a 300 ohm resistor. That should put 16 mA through those pins - which should be enough load and still perfectly safe.
Of course the other thing is that you definitely need a good ground on the DRV chip. I think you said you soldered the ground pad through the bottom of the board - right?
Had a similar problem with the rails being low, solved by re-soldering the DRV ground pad properly in my case.
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And it didn’t catch fire on the 100 ma supply. Firmware flashed and ready for a real test.
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@shaman Any news about v1.0? I heard that you still wanted to test some aspects of it before saying that all is good. We are all using 0.9 right now, but there is a need for like 15-20 focers now, so our group is waiting for some updates 
Thanks!
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Yeah sorry for the lack of update on that
I’m really busy right now with getting the little FOCer to market. V1.0 of the CFOC2 is sitting in the dev branch in the repo. The only thing I’ve found to change so far is getting rid of the PNP transistors I added to each mosfet gate. They don’t help much and aren’t worth it.
Sorry I can’t really push v1.0 any further right now. Anyone else who wants to help is more than welcome. It’s an open project after all
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Are there any serious improvements to 1.0 version apart from just minor ones? If we are OK with v0.9, should we expect something more from v1.0? Because if nothing is severe, we are totally fine with v0.9 and we can go for that again
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I thought I posted a changelog but maybe not. I can do that at least here soon. There are other changes that make it worth it in my opinion
Yeah, if you could do that, that would help us a lot. As now it is winter here, so people could wait for a few months or so if you see yourself getting with v1 somewhere
Thanks.
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For what it’s worth I ordered 15 v1.0’s and have assembled one and it appears to work well.
I much prefer the capacitor layout and the option to use a dupont connector for the PPM input is nice.
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Just so I understand - you’re not saying the PNP transistors do any harm; they just don’t help as much as you hoped - is that right? The only down side is the cost? By “getting rid of” them, do you mean replacing them with something more effective, or just nix them to save the cost?
With V1.0 as it stands, would you still recommend it over v0.9?
Thanks!
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Yes they’re just not worth the extra cost. I would just get rid of them. Proper selection of a MOSFET goes further than them.
Yes due to the other improvements I’ve made.
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So it seems that LCSC does not have the BMI160 or the 330uF capacitor in stock anymore (well, the BMI160 can be back ordered to the tune of $6 a pop)
What would be another good place to get these? (internationally?)
https://www.digikey.com/en/products/detail/bosch-sensortec/BMI160/6136300
DigiKey is international.
https://www.aliexpress.com/item/32756477916.html?spm=a2g0o.detail.1000014.3.72167f24NUJanZ&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.13338.183346.0&scm_id=1007.13338.183346.0&scm-url=1007.13338.183346.0&pvid=7d2f49f5-bf52-4587-8420-88da72326847&_t=gps-id:pcDetailBottomMoreOtherSeller,scm-url:1007.13338.183346.0,pvid:7d2f49f5-bf52-4587-8420-88da72326847,tpp_buckets:668%230%23131923%2360_668%23808%234094%23788_668%23888%233325%2318_3338%230%23183346%230_3338%233142%239890%239_668%234328%2319924%23143_668%232846%238114%23757_668%232717%237558%23143_668%231000022185%231000066059%230_668%233422%2315392%23180
These are cheap. You could just order this module and then harvest the BMI160
You don’t necessarily need 330uF. this should do
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Ah, that’s an interesting idea, I hadn’t considered taking the chip from one of those little boards
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