Puma board for FreeEMS

[jharvey]

Ping Ping, just wondering how it's going.

[nitrousnrg]

haha, I'm alive.

This friday 17th I have the last exam of the year. The plan is to take 10 days to finish the design, and send the PCB for manufacturing in december as expected. Then, while waiting for the boards, finish the oven (just wire up the modules I've been building), and set up the BDM programmer.

I'll be back with the dev in a couple of days :-)

Btw, I held in my hands an amazing board. It was a feescale flexis dev board, with black soldermask and goldish graphics that came up from exposed gold plated copper, it was pure art.
Check it:
http://hw.cz/system/files/redaktor130/090712_DK.jpg

[nitrousnrg]

Ok, 6 extra CPU pins are available in the 40-pin header.

Those are:
* PT6
* PT7 (now all the port T is being used/available)
* PM0-PM3

Its pushed up. Now its time to get the silkscreen readable. Still needs some pads to test the other ports.

Last night I sent a mail to the manufacturer to save time, I hope he replies this monday.

[jharvey]

It's looking good. I have some minor notes, here they are.

-- In "macros's notes" I believe TOTAL 30.47A should be mA not A.
-- release_notes.txt, TODO.txt, and change_log.txt appear to be my old files. They can probably be emptied, deleted, or what ever.
-- A couple devices like U17,F1,F3,U6 and U5 don't have 3D wings models, and are not shown in the 3D view.
-- In the 3D view it shows U28 ect interfere with each other. Some times the silk screen and/or 3D model on those devices is a bit off. Have you checked the actual parts on paper for this device. I believe you have checked the SMT foot prints, however this thru hole may be a bit tight as well. Probably good to check if you haven't already.
-- You choose the uMax 10 foot print for the max9924. This is a fairly small device and it would probably be easier to assemble if you used the choose the slightly larger 16 QSOP package.
-- Some of these parts will be hard to attach a scope to. Perhaps some more test vias for test points might be handy as a place to connect a scope.

[nitrousnrg]

Thanks!
* notes corrected
* I'm going to keep the files, but moving them somewhere else (later)
* yeah, I searched a lot for the 3D model of the LQFT112 CPU. It would be great to have it. Also, the model of the diodes is incorrect, its way too big.
* Those ICs are injector drivers, and the model is kinda big. The ICs fit :-)
* Its freaking small! Anyway, I already have them, and saves a lot of space. If I can assemble them, I'm keeping them.
* I'm working on that.

Silkscreen is almost done. Not pretty but readable. I want to separate some resistors because they are too tight and there isn't solder mask between them.

Its getting close

[Fred]

Marcos, you're using version control, it remembers everything, either delete them, or update them. Moving them and leaving stale contents in there is not a good option. Just my advice, if you want, you can listen, if not, no problem :-)

[nitrousnrg]

I'm putting it in a folder named "previous work" under the "docs" directory.

Changelog and release notes reflects the work I didn't do (schematic desgn, for example). I deleted the TODO.txt, nothing related to Puma there.

A few components (3, I think) won't have reference in th silkscreen, the space is too tight. A bunch also won't have reference, but they are mostly diodes or .1uF capacitors, its easy to know what to put there.

Still waiting for the manufacturer to show up...
Ok, now a last try to put some knock detection.

Today I separated a pinch lots of resistors. Some are very close, like R156-C82, but in those cases there is't risk of a bridge (they are connected anyway). This was important, I'm sure I would't be able to assembly the components without mask between them.

The crystal is something to be aware of, it looks more complicated to solder than the uMAX-10 package.

[Fred]

"Today I separated a lot of resistors by a pinch" - might be better :-)

What are your knock detection ideas? I think it's likely that it'll use that IC designed for it. Keen to hear what you have in mind.

Fred.

[nitrousnrg]

cool, it was hard to read.

So far, I'm afraid no knock circuit will make it to this prototype. First, because I couldn't get any of those chips that handles all the signals and produces a nice digital output. Second... ehmm no, there is no second. I just couldn't get one of those chips.

Nevertheless, I had in mind some analog circuitry, at least to try it out. That's what the connector board is for: testing! I don't like going analog, but it worths a try.

I had a brief communication with Caaarlo, a guy from San Luis, Arg years ago. He tried a second order passband filter, centered in 7.8KHz. I wanna try something like that too, with some Schmidt triggering. Probably it isn't flexible, accurate nor reliable to meet this project needs, high rev noise is quite a pain. You may want to take a look at this link
The filter coefficients could be adjusted on the fly by software, though.

Ion sensing, in my opinion, is the way to go. A fairly small DSP surely can do that work, but I need lots of time. The only shame are those who already have the knock sensor. Forget about it, its not a good idea for this stage of the project.

[Fred]

Agree, knock sensing is a secondary function anyway. While tuning, it is ineffective at providing real time feedback to the tuner. A mechanical or audio listening system should be used while tuning. Open loop, if tuned right, is mostly fine without knock sensing. Knock sensing has a primary function of allowing OEM cars to not blow up when running on crap fuel that an idiot owner/user put into them. If you run good fuel, and have a good tune, you don't need it.