Thank you very much indeed. Good to know that the PRO guys with their falcon-vision are spotting the errors.
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GREEN light, and a lot of BLUE. I have now adjusted the resistors so I get more of the green.
So this means that the newly compiled VESC executable with hwconf for FOC_KING is running and no detected hardware errors so far. And I can connect to the board from the VESC tool.
However, I’ve had to attach a huge temporary heat sink to the LDO, because it’s getting too hot, which I kind of knew before I received the boards (two of them). In the schematics and layout this is already fixed with the addition of a secondary buck converter.
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This is such a cool project. Good luck homie
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In the newer schematics of the VESC6 there have been added three analog switches for being able to switch in and out the 15nF filter-caps on the current measurements. To find out what these switches are actually doing, I have been looking in to the vesc source code.
I assume that PHASE_FILTER_ON() means that the 15nF is switched active in the circuit and PHASE_FILTER_OFF() it is switched inactive.
It seems that the 15nF filter is allways active in “online” mode, which is everything except Motor Parameter detection stuff. This is my impression - but I might be wrong.
The filter is specifically turned off during some of the motor detection stuff - like e.g. measurements of inductance. It makes sense…
So I just found out that the MC74VHC1GT66 analog switch is actually available cheap and well-stocked at jlcpcb / lcsc, so I think the FOC_KING will need these switches in order to be a true KING. I’ll add them, why not? In particular the One-Wheel seems to be very sensitive to correct motor-parameters for HFI and BEMF measurements. The torque at zero-speed that we like very much.
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Mosfets are switching - also those that are supposed to be switching. Haven’t received the correct mosfets yet - they will arrive in a few days.
Also low-side current sensing for all three phases seems to be working as expected - so far.
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More than alive…
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FET Arrangement ?
Heat sink is connected electrically to the drain of the mosfet, so this gives me an idea. BUT is it a good idea or a really bad idea. I think it makes manual soldering much more consistent, and it should give a low impedance path between the high side mosfet drains. Positive wire is much better attached to the board in this way (more resistant to the vandalism that such a board will be exposed to).
Phase wires can be attached on the front-side of the board through 3 drilled holes, and then soldered to the heat sink of the switching nodes of the bridge (which happens to be the heat sink of the 3 remaining mosfets).
Soldering is obviously not on the “sink” side of the mosfet, but on the part of the heat sink that is visible from the front side of the mosfet.
Where are hall sensors connected?
My response from Apr 22nd…
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Sweet, will it have support for a power button?
You don’t want to use current filters on a low side shunt design.
The phase voltage filters are a good idea though.
The sampling data looks pretty noisy. There is a similar issue with the 75200 and it caused a lot of problems running motors smoothly.
4 layers instead of 2 layers would probably help a lot by having ground planes close to the signal lines for a short current return path.
Cool to see the progress on this project!
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Hey, Thanks… I got it wrong here.
And thanks for the link. I think it will help me a lot. If you have more - just feed it to me.
Yeah, why not. It’s on the list now. Thanks
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How many Layers?
Currently, the board has only two layers, and the dimensions are 90mm x 62mm, which is 5580mm².
Some simple math on pcb board prices from JLCPCB:
2 layers: 1$ per 5000mm²
4 layers: 1$ per 1250mm²
This means that the price for 1 board is: (yeah, obviously without components…)
2 layers: $1,12
4 layers: $4.46
That is additional $3.34 for a 4-layer layout. I don’t think it’s a lot, considering how crazy the price of an original vesc board is these days.
Well, what do you think?
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OPENAI: PCB boards: 2 layer vs 4 layer?
When designing a printed circuit board (PCB), one of the decisions that needs to be made is the number of layers to use. The most common options are two-layer and four-layer boards.
Two-layer PCBs are the most basic and affordable option. They have a layer for components and traces on the top and a layer for traces on the bottom. This type of board is suitable for simple circuits, and the routing can be done manually.
Four-layer PCBs have two additional internal layers for routing, providing more space for components and reducing electromagnetic interference. They are more expensive to manufacture than two-layer boards, but they offer better signal integrity and can support more complex designs.
In general, if you have a relatively simple design with few components and traces, a two-layer board should suffice. However, if you have a more complex design that requires high-speed signals or high-density components, a four-layer board is usually a better choice. The additional layers can help reduce signal noise, shorten signal paths, and improve the overall performance of the circuit.
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Most of the money is gonna go on components, so if you keep most (ideally, all) on one side and can improve signal integrity by going to 4 layers, go ahead!
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