Processor 2025 Full Review

[Armaan-Sengupta]

No description provided.

[Joe-Joe-Joe-Joe]

1. Why is this called "spi_addr"? Shouldn't it be "I2C_addr" or smth?
   
2. For net labels beside hierarchical ones they are not technically overlapping but still very hard to read. Please extend one as has been done for CAN Tx/Rx above
   
3. This is my failure from before but this should live in the whitespace on the right side and have a net label to PH0
   
4. Please point power symbols up and grounds down always
   
5. What....
   
6. Is this fuse value on 5V still accurate? Same with R1. Have you actually done your power draw calcs somewhere? If you need a reference, "processor board current"
   

[Joe-Joe-Joe-Joe]

7. When you do get to layout, make sure you annotate the axis directions of the LSM clearly on the silkscreen. Also note that their "X" and "roll" axes are different, which is not the same as our (well, my, but nonetheless the correct one) axis convention for the rocket
8. What does Movella Sync In/Sync Out do? Does it make sense to connect it to timer pins (I think you have those free somewhere)
9. D:
   
10. Inductor packages tend to be nonstandard. Have you selected a specific inductor for L1? There is a datasheet section on inductor selection which you should read if you haven't already.

[AshTheEngiqueer]

1. Pin 6 is a NC pin for the 2568? If so, no point in including it in the symbol.
2. Max current on the buck is 1A - are you sure this is sufficient? Have you double checked your current draw maximums? It seems pretty close from my review of the controls 2024 spreadsheet and the changes made, but I'd double check.
3. nit but the datasheet on U5 links to the page on stm, rather than the datasheet pdf
4. Not super familliar with I2C but what's the justification for the DNP resistors R16/17/19/21?
5. also nit but there's some inconsistent formatting with resistor values - there are 10k resistors marked as 10kΩ or 10kR. afaik team standard is 10k, same with capacitors (1u vs 1uF)
6. Bold to assume you can find an inductor with a standard footprint - take a look on digikey for the right value and see what you find, pick something and use it's footprint. We ran into issues with finding standard footprint inductors with charging board last year, and I suspect you'll find the same this year.

[Armaan-Sengupta]

@Joe-Joe-Joe-Joe :

1. Yes sry, too much SPI at work
2. ty
3. yea good idea, didnt notice that was the only connection lol
4. 👍
5. test that you are really getting 3.3v before it powers the entire system up potentially breaking everything if it is not 3.3v (ex. wrong resistors for voltage divider), then just put a blob of solder there to connect
6. I have not, just carried over, thanks for catching that. But upon checking it should be fine, buck allows current to be a bit lower, but that should be fine.
7. Good idea, I will follow the sensor's coordinate frame rather than our team standard
8. I dont think they will be required, they are there primarily because harwin is 6 pin, lol. I think we are most likely to use the Sync In if we want to specifcally request data at that instant. Yea I can tie sync in to a clock line, I still think we will probably use it as a regular GPIO but doesnt hurt.
9. Fixed
10. I did, but I would like to read that resource to check against, can you send it?

@CasualIntellectual :

1. Its a vendor part, id rather just leave it to match the datasheet, and so we dont need to modify the provided file
2. Yea, it will be less than 1A, calcs linked above
3. Fixed
4. We can place them if we want, resistors in parallel lower the equivalent resistance (weaker pullup), RC time constant goes down, we can run I2C faster if we want
5. Fair enoug for resistors, just thought it looked nicer, but removed👍 . For caps it looks really strange IMO, but if its fr a team standard we follow I can remove it (same for inductor ig).
6. I did check, and just oversized, I think its too oversized, ill learn how to make a custom footprint during routing

[Joe-Joe-Joe-Joe]

I did, but I would like to read that resource to check against, can you send it?

You want me to send you the datasheet for the buck converter?

I did check, and just oversized, I think its too oversized, ill learn how to make a custom footprint during routing

Please don't do this unless you cannot find a footprint for it online.

[Armaan-Sengupta]

10. datasheet section on inductor selection

Oh I assumed this would not live in a specific Inductor's datasheet, but rather be some kind of general third party guide. If not nw.

[AshTheEngiqueer]

1. This via is only connected on one side, I think you can just remove it?
   

2. aaaaaahhhhhh what is this daisychaining
   

3. Is there a reason why all of your test points are through-hole?

4. There's a lot of pad-silkscreen overlap in general

5. Test points not labeled?

[Armaan-Sengupta]

1. Good catch
2. Good point ty
3. Not all, the I2C ones are not, where I had space to fit them, I made them through hole since its more convenient
4. Yup hadnt gotten to cleaning that up yet, you got the jump on me before I PR'd this lol (but ty I appreciate the early feedback)
5. Which ones? Most are looks like I missed the 5v and gnd inputs, still need to work on silkscreen stuff

[Armaan-Sengupta]

@Joe-Joe-Joe-Joe @AshTheEngiqueer @JasonBrave full PCB ready for review

[Joe-Joe-Joe-Joe]

1. Round your corners
   
2. Why are the hole spacings nonstandard? Should be in increments of 0.5in
3. I don't have time to dig through it all but you should think about how your harness connections are oriented. Right now, if someone connects the rocketCAN harness to the pololu connection inadvertently, they will expose the 3v3 line to -5V and that's generally bad
   
4. Nit, but I would prefer "RocketCAN" over "Main Harness". Less ambiguous
5. What is this?
   
6. Avoid daisy-chaining pads (yes this might have been me lol)
   
7. SDMMC_D0 should be length matched to the other data and clock lines. Something like this is easy enough
   

[Armaan-Sengupta]

1. yea was planning to do at very end in case any modifications required changing board outline (does anyone know how not to make this a PITA once fillets are added?). If no one else has anything in a day ill consider it final and fillet the corners
2. oh they are just in mm, inches moment, sigh okay I forgot we do imperial here lol
3. Yea I like that idea, ty. Btw In specific, the old setup that scenario would have resulted in 5V being connected to gnd (not 3.3v):
   
4. Yea I thought since it was also main power supply, but nvm I like that more asw
5. Good catch ty
6. Yup good catch missed it ty
7. Oh damn speedy boy, 24Mhz, didnt realize, will do.

[AshTheEngiqueer]

1. Daisychaining
   

3. Still no rounded corners?

4. 90deg trace aaaa

In general looks alright apart from lots of daisychaining/bad practice (traces out of pads at 45deg angles, or way off center, or just interesting routing decisions)

[Redstone-ray]

Is Daisychaining bad practise? I don't understand. (This is purely just me being curious)

[Rio6]

If you daisy chain and someone skill issued during soldering and ruined the pad, the entire trace is ruined.

There are arguments for and again the 45deg trace but in the end is purely for aesthetic for us like rounded corners.

[Armaan-Sengupta]

I was told by someone way back in my first coop when I first designed a PCB that 90 degree traces are bad for boards with extremely fast signal speeds, and have generally just stuck with that, but in reality I think it does not rrly matter, ig I just missed this one as the 3 way joint let it elude me, will fix.

Yea I keep getting caught on the daisy chaining stuff, lol ty, I do generally try not to daisy chain, because yea like Rio said if someone ripped the pad of (which I think is actually not too uncommon), the entire "bus" is ruined. I will make sure to go through the entire board not just the stuff I worked on to check for it 👍.