HotCat's CatPower CPU board & PNP IO/Power board for Citroen

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DeuceEFI
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Re: My core board & I/O board design, need your comments

Post by DeuceEFI »

Fred had asked for me to give your project a once over, so here goes:

Based on your commit with Hash: 42c7c0b346bbd1a60e1466cb79e18170f2867ce7
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On catsquirt.sch:

C1, C2, C3, C5, C9, C10 should be 0.22uF/50v X7R Ceramic capacitor

C2 should have a parallel 10uF/10v Tantalum capacitor

C3 should have a parallel 10uF/10v Tantalum capacitor

Consider changing the PLL values to Fred's recommended values:
R1 3.3k
C6 6.8nF
C7 680pF

For the crystal, if you choose the same ECS HC-49US:
C4 and C8 can be anywhere from 12pF to 22pF, just need to make sure the crystal oscillates.

On the BDM, consider changing R6 from 4.7k to 10k to reduce the number of different values of resistors. The value really isn't critical from my testing.

I'm guessing from the rest of the schematics in your project file that catsquirt.sch was for a prototype board before you started working on the mainboard.sch as the actual board to use on your car.

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It appears that catsquirt.sch and prototype.sch are also other prototype boards.

I would recommend removing catsquirt.sch and prototype.sch from your project file as they make it a little confusing to figure out which one you are developing for your car versus what you are using on your test bench. :-)

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On Core Board.sch:

It appears that you have been keeping up with my Jaguar board, which is good as Fred, Dan and TonyS and I have been working out the details and I am very close to etching a prototype board to test on my car... :-)

It also appears that some of the libraries that you used don't exist on my PC since they show up as boxes with ?? in them when I look at this schematic, but could be that I don't have your library loaded.

C24, C39, C42, C46, C47 and C50 should be a Tantalum capacitor as electrolytics don't last very long in high temperature applications.

C46 on your schematic should be changed to 47uF/10v Tantalum as I have changed it on my schematic to match your equivalent of C50.

R12 could be 1M or 10M, not sure which is correct. Technological Arts used a 10M resistor and so did I on my prototype board and I am considering changing to a 10M resistor on the Jaguar board as well.

For the crystal, if you choose the same ECS HC-49US:
C17 and C21 can be anywhere from 12pF to 22pF, just need to make sure the crystal oscillates.

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On VR Interfaces.sch:

Make sure that R63 and R65 are 1/2W resistors, and I recommend using a 1W resistor for R28.

I recommend than you use a 2.4k 1/4W resistor for R29, but if this causes an issue with your RPM input to the CPU then you can always remove it.

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U_Core Analogue Inputs.sch looks good except for the boxes with ?? in them, but could be that I don't have your library loaded.

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On Low Side Drivers.sch and Injectors.sch:

Consider changing from VNP10N07 (100mOhm On-State Resistance, rated 70v @ 10A) to VNP14NV04 (35mOhm On-State Resistance, rated 40v @ 18A). This change will result in less heat generated while the device is in an "ON" state. They both have the same pinout so they are direct drop-in replacements.

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For U_Ignitor Outputs.sch I don't have much useful information as I haven't looked at driving ignitors for my board.

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I would like to find out more information about your circuit on U_Dashboard Analogue Outputs.sch as this could be helpful for my Jaguar board to supply a usable Tachometer output to run the dash tachometer for GM vehicles with DIS ignition. :-)

Let me know if you have any questions about my comments as I may have been less than clear about the reasoning for them. 8-)
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Re: My core board & I/O board design, need your comments

Post by Fred »

Thank you very much, Andy! :-)

About the FET part numbers, the older ones are cheaper and pretty much just as good. It's not a concern, use which ever you can get easily/cheaply there for those.

I'm curious about dashboard outs too, maybe start a thread on that, HotCat?

For the VR LED situation, you should use the highest value resistor you can that still lights up the LEDs. 2.4 is likely to work OK. We will soon see.

Fred.
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Re: My core board & I/O board design, need your comments

Post by HotCat »

DeuceEFI wrote: I would recommend removing catsquirt.sch and prototype.sch from your project file as they make it a little confusing to figure out which one you are developing for your car versus what you are using on your test bench. :-)
I'll delete extra files and keep a tidy project as your Jaguar did
I would like to find out more information about your circuit on U_Dashboard Analogue Outputs.sch as this could be helpful for my Jaguar board to supply a usable Tachometer output to run the dash tachometer for GM vehicles with DIS ignition. :-)
I use a inverting MOSFET driver mc34151 to drive my Tachometer using PWM
Thanks for your advise on my schema, I'll adopt them all
About missing schema library, I think it is the bug all about KiCAD. Here is the fix
Add the library manually
10.PNG
select the library file freeEMS_lib.lib
12.PNG
and save the setting to catsquirt.pro
13.PNG
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Re: My core board & I/O board design, need your comments

Post by Fred »

Does the tacho take PWM or a frequency based input? Your chosen pin allows either, so no big deal, I'm just curious about your tacho :-)
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DeuceEFI
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Re: My core board & I/O board design, need your comments

Post by DeuceEFI »

HotCat wrote:About missing schema library, I think it is the bug all about KiCAD. Here is the fix
Add the library manually
That fixed the issue, the schematics look a lot better with the library loaded... :-)
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HotCat
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Re: My core board & I/O board design, need your comments

Post by HotCat »

Fred wrote:Does the tacho take PWM or a frequency based input? Your chosen pin allows either, so no big deal, I'm just curious about your tacho :-)
My tacho take PWM, it is not a smart device, just something like mechanical multimeter
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Re: My core board & I/O board design, need your comments

Post by DeuceEFI »

Just wanted to let you know I updated the ground connections to the pull-down 100k resistors on the injector and outputs sheets on my Jaguar project. I had run them to the Injector-GND and the other Hi-Power-GNDs when they really needed to be run to the same ground as the CPU-GND on my board. Take a look when you get a chance to make sure you correct your schematic as I have done. :-)
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HotCat
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Re: My core board & I/O board design, need your comments

Post by HotCat »

DeuceEFI wrote:Just wanted to let you know I updated the ground connections to the pull-down 100k resistors on the injector and outputs sheets on my Jaguar project. I had run them to the Injector-GND and the other Hi-Power-GNDs when they really needed to be run to the same ground as the CPU-GND on my board. Take a look when you get a chance to make sure you correct your schematic as I have done. :-)
Copy that, but I am not agree with your gnd design and so is Fred. You should isolate hight current gnd from CPU gnd. And the two gnd must meet together at engine block. Check my gnd design thread and my schema
viewtopic.php?f=9&t=1557&start=20
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Re: My core board & I/O board design, need your comments

Post by DeuceEFI »

I found out that the NEC PS2911-1-3A optocouplers for USB isolation are not fast enough for our use, but Dan and Fred have found some new ones that they would like to test and I have ordered some Avago HCPL-061a optocouplers for testing on my Jaguar PCB. Just wanted to let you know :-)
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Re: My core board & I/O board design, need your comments

Post by Fred »

HotCat, sorry for the huge delay doing your diagram... I'll try to get it done today.
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