Puma board for FreeEMS

[nitrousnrg]

Inj circuits are in standby, you can see TO220 were replaced by D²PAK, and DIP8s went to the bottom side. I did the pre-layout for only 2 of 8, just in case I'm not satisfied with the testing.

For p&h drivers with the LM1949 controlling the transistors in linear mode? With up to 10W per driver?

My testing consist in trying out the PWM mode :-)

[jbelanger]

Inj circuits are in standby, you can see TO220 were replaced by D²PAK, and DIP8s went to the bottom side. I did the pre-layout for only 2 of 8, just in case I'm not satisfied with the testing.

For p&h drivers with the LM1949 controlling the transistors in linear mode? With up to 10W per driver?

My testing consist in trying out the PWM mode

Good. But watch the temperature of the Zener and the noise. And I'm interested in your results.

[nitrousnrg]

Inj circuits are in standby, you can see TO220 were replaced by D²PAK, and DIP8s went to the bottom side. I did the pre-layout for only 2 of 8, just in case I'm not satisfied with the testing.

For p&h drivers with the LM1949 controlling the transistors in linear mode? With up to 10W per driver?

My testing consist in trying out the PWM mode :-)

Good. But watch the temperature of the Zener and the noise. And I'm interested in your results.

Yes, the datasheet mentions the zeners extra power dissipation, so its big.
Noise could be high in that zone, but as long as it doesn't get in the CPU or analog circuits I'm fine.

If the PWM path doesn't look good, I'm leaving the DPAK stuff for high-Z setups, and adding TO220 footprints for P&H.

[TonyS]

Marcos,
Is there a pdf of the Spin 2 schematic (I realize that it is a work in progress)?

Thanks,
- Huff

[nitrousnrg]

Marcos,
Is there a pdf of the Spin 2 schematic (I realize that it is a work in progress)?

Nope, only as .sch so far. I'm upgrading my system right now, in order to install the newest kicad version. Maybe it has some super nice features. If not, I can setup a pdf for you, just let me check the new version (1gb remaining, should be ready tomorrow).

I'd love to be able to generate a clickable/browsable HTML version of the schematic hierarchy...

Oh, on a side note, I found that some guys programs microcontrollers using the FT232. It has bit-bangable pins, and it has been used extensively in Arduinos AFAIK. Its hardly possible to satisfy BDM timing requeriments, but it worths the note.

[jharvey]

After seeing the size of the heat sinks and such in the Cinch, you may want to consider using that for PUMA as well. I think those can dissipate quite a bit of heat. I'm downloading CAELinux now so I can make some pictures that show how the heat would leave that case. When you can make that full board vrml, let me know, I can use that in CAELinux with the case to predict heat flow. Or at least I could with the 2008 version, so I'm assuming I still can.

[Fred]

Its been quite a lot of work, the TODO for spin2 had almost 50 items, and now it is getting closer to completion

Mean while, NO one, other than you, has placed an order for parts!!!!!! WTF... have some focus! Do you really expect anyone from the spin 1 group to be in on spin 2 if spin 1 is a total disaster (from an actually getting used perspective)? Imagine the firmware progress that might have been possible by now if people had units hooked to engines! Such a shame....

Following the topic, I prefer to change 6 lines of assembler rather than add 21 resistors to the board.

This does NOT solve the reset state issue. Jean said something about a single pin, but I don't see how it's possible for that to be done without FAR more than 21 smd resistors worth of componentry(in order to disable/default vulnerable pins during the reset period by force based on some trusted pin?). Care to elaborate on that, Jean?

I was thinking about Jean's comments today, though, and I realised that it is far better for me to specify a required behaviour and allow a free choice in implementation! The trouble with this is, that it's MUCH more difficult to know if a system is compliant because it would require detailed testing of an actual unit. The questions then appear:

Who should pay for such test units?
Who does the burden of testing fall on?

Clearly I can't just take the designer/manufacturer's word that it's OK, I, or someone that I trust, must perform the tests, or two people independently should do them, and verify each other's results. So then perhaps a manufacturer should pay to have their stuff certified as "FreeEMS compliant"? Perhaps it would be good to have this as an option, and something that can be statically analysed as an option for those not wishing to adventure with design too much.

In any case, being FreeEMS compliant is purely optional. All hardware solutions will have a comparison page written by me with known weaknesses and strengths highlighted. If someone wants their design to be recommended by the FreeEMS brand, then they (will) know what they need to do.

Having firmware depend on this piece of code (monitor or bootloader) for anything is totally wrong. The firmware has to act as if the CPU just got out of an unknown state and initialize everything. If changing the initial state in the bootloader has an impact on the firmware then the issue is on the firmware side not the bootloader side and should be corrected there.

The guy was stating the obvious.

Fixed! This was not relevant to the discussion on bootloaders, there was some talking at cross purposes going on.

Fred.

[nitrousnrg]

Mean while, NO one, other than you, has placed an order for parts!!!!!! WTF... have some focus! Do you really expect anyone from the spin 1 group to be in on spin 2 if spin 1 is a total disaster (from an actually getting used perspective)? Imagine the firmware progress that might have been possible by now if people had units hooked to engines! Such a shame....

Hey, the BOM I used was online before the pcb was manufactured. We all know its not easy to assemble it, and that it needs a engine to run, a programmer, time etc. I didn't had any feedback bout the assembly manual, so I guess no one read it. Probably because is not online as a pdf. Push the last website changes online, and lets hope for an avalanche of feedback.

[jharvey]

Last I recall, most that haven't purchased parts have been no doing it on Fred's recommendation. Shrug, not much we can do if they listen to you I think the largest hurdle they'll have is the BDM. I'm a bit concerned about Spudmans issues. I wish I knew how to help, or had better info to work from. Sounds like his should be working, but has some kind of unknown problem.

[Fred]

Perhaps there is a communication issue here.

I've explicitly TOLD everyone NOT to bother reading it until it's finished (BOM and instructions). Once you tell me it's finished, I will read it, and we'll polish it, and then I will tell everyone to go ahead and order based on it all. These people are user level, mostly, and although feedback from them is good, The minimum required is to be able to order and not order the right and wrong parts, respectively, and that in itself requires an good understanding of everything that is wrong/changed/different from when you ordered originally.

I just read Jared's post, he's dead right. I don't want my friends and others to go and order a bucket of parts that turn out to be wrong, and be left needing a second order (and shipping etc) for stuff that was missing.

Spudmn will get his unit working, no stress there.

Fred.