Puma board for FreeEMS

[nitrousnrg]

37 boards have been made and are being distributed soley because *I* spread the word, and because *I* recommended them to my friends and acquaintances. Marcos was going to order 4. Don't think I have any loyalty to anything but the best outcome here. If a device isn't up to spec, I will not publicise or recommend it. That will reduce the quantity of buyers and testers significantly. It belongs outside the box for many many reasons. I'm not going to list them. I don't have time.

This was unnecesariy, jharvey said something reasonable and your comment was off topic and not constructive.

Come on guys, we are a team. Its 9am here and I've been awake for many many extra hours searching for a short. We all are making big efforts for the project, so lets be gentle with each other.

I measured more. XGATE is enabled now, so it'll be higher again. I may have cocked up the measurement, but I don't think so. I've also measured my cpu a significant amount above ambient due to that power dissipation. This info is somewhere in my hw thread.

I'm aware of your measurements, but I believe the high temperatures you got were because of driving so many leds with the MCU. I could be wrong.
I still believe the system can be designed to stand the magic 125° mark :-)

Now installing mtx to get some info from the MCU...

[Fred]

This was unnecesariy, jharvey said something reasonable and your comment was off topic and not constructive.

I beg to differ. It was necessary because an "I'm not listening" attitude is fundamentally unacceptable on this forum. My prior comment was legitimate and valid. Do not waste any more time on this subject. Posts after this one referring to this shall be moderated simply for wasting more of my time and yours.

so lets be gentle with each other.

I've invested my entire life into this site and project, every waking hour for years, it's no joke, if I perceive it's not being taken seriously, I'll likely not be too gentle.

I'm aware of your measurements, but I believe the high temperatures you got were because of driving so many leds with the MCU. I could be wrong.

All LEDs were/are buffered with transistors and those are driven through 1.6k resistors which keeps the current within spec. Thus, even if you're right, which you may well be, this is a reasonable amount of current and heat to expect in a functioning EMS that is actually driving pre-driver loads for its various outputs.

I still believe the system can be designed to stand the magic 125° mark :-)

Quite possibly, however next time the inside of your car reaches that level, let me know, I'm coming to scrape your remains out onto the road and salvage the car.

Fred.

[jharvey]

Come on guys, we are a team.

Agreed. Fred has a lot of passion, which is good. He's generally a principal based personality, which seems to be a significant source of his energy. A key with him is to identify his principals, then his actions tend to make a bit more sense. We're all working to goals with overlapping objective. However we all have different end goals. I believe that's nearly the definition of a team.

Hmmm, short you say. Can you verify the board was good to start with? Perhaps checking the other boards. I'm guessing you are looking for solder shorts, it's possible the board has a bridge, instead of the resulting solder. Sparkfun recommends that with a PCB house that claims 8 mill trace and 8 mill gap, to use at least a 10mill gap. This is because the angle traces will often still fail. That 8mil tolerance is often in the x,y, and get's amplified a bit on an angle. I seem to recall the gap was 10 mill, so this shouldn't be a problem, but I'd have to go double check to know for sure.

What trace appears to have the short? There is also a chance it's a net list issue. So it could be shorted with out being an obvious bridge.

We can verify the max temp by putting this in an oven, and cooking it. That's a bit down the road. When the time comes, i know a fellow with a thermal camera. He may allow me to do a check with it.

[TonyS]

Are up-to-date schematics and BOM for this design currently available in pdf format? I know that the schematic version on the "Puma" site is not current, but is this where I would normally try to find pdf versions of the current design docs?

- Huff

[nitrousnrg]

Hi Tony Stark,
try https://github.com/nitrousnrg/puma, there resides all the files related to the design

jharvey, I agree about Fred's source of superpowers.

And, the short was already fixed, it was a tantalum putted backwards. I got quite pissed off about that, wondering who was the professor that told me they've no polarity (I was *sure* they don't have, I wasn't ignoring that fact).

[TonyS]

Hi Marcos,
I could not find the pdf version of the schematic at the link you provided. I do not have KiCad (nor do I want to install it). I just wanted an up-to-date reference to use while following these discussions.

- Huff (I'm no Iron Man - just ask Fred : )

[nitrousnrg]

Hi Marcos,
I could not find the pdf version of the schematic at the link you provided. I do not have KiCad (nor do I want to install it). I just wanted an up-to-date reference to use while following these discussions.

Oh, the pdf version of the schematic is up to date except for the MCU VCC1 and VCC2 wires. Nothing else has changed. pdfs are generated manually, and up to now, always by jharvey.
The pcb changed a little, though.

- Huff (I'm no Iron Man - just ask Fred : )

aww

[jharvey]

It appears the PDF's posted on puma.freeems.org are the same as this spin. They include spin1 in their names. There is a slightly updated version of PUMA in the git repository. Also a prior commit of the git version of PUMA is a snap shot of the KICAD files. Such that if you wanted the KICAD copy of it as it is designed now, you can grab that commit.

[Fred]

Hi Tony Stark

ROFL, that would have gone right over my head if not for someone forcing me to watch both movies recently.

And, the short was already fixed, it was a tantalum putted backwards. I got quite pissed off about that, wondering who was the professor that told me they've no polarity (I was *sure* they don't have, I wasn't ignoring that fact).

And, the short is already/has already been (was would work if you were referring to others doing it, it's not wrong as such, it just sounds strange) fixed, it was a tantalum put in backwards. I got quite pissed off about that, trying to remember who the professor was that told me that they are not polarised (again, just more normal) (I was *sure* they weren't (to match), I wasn't ignoring the fact).

I told you this on skype the other night! You should trust you faithful leader ;-)

Fred.

[TonyS]

A couple of general suggestions regarding schematics.

1. In my opinion, 56 pages is way, way, too many sheets for a design of this complexity. I do understand why some people may choose to use a hierarchal schematic design approach, but I really see no need to have page after page of a single resistor with a single diode (or a few that have no components at all). It really makes it somewhat difficult to navigate the design. I tend to use a "Main" sheet (shows connector(s) assignments) and then full sheets of sub-circuits (Input(s), Output(s),...).

2. You will have to assume that some users will not use KiCad, and will be relying on pdf versions of the schematic (or printouts) while building / troubleshooting. Because of this, I would suggest using the smallest standard sheet size for all of your sheets (we use "letter" size, but I think "A4" is what the civilized world uses). Also, I was not able to search for a component (i.e. "R101") using Acrobat Reader on the pdf version of the existing schematic. I am able to conduct searches in schematic pdf's that I generate, by "printing" to a free pdf creating tool called "FreePDF" from within my design tool. I don't know though, if it is my schematic capture program or FreePDF that allows this.

- Huff