FreeEMS hardware feature wishlist (your suggestions here!)

[FlappySocks]

I havn't had any experience of the IRGB14C40L, but i use the Fairchild ISL9V5036P3 IGBT Ignition Drivers instead of the VB921's for my megasquirt projects. Cheaper, and run cooler.
http://wiki.diyefi.co.uk/Fairchild_ISL9 ... ion_Driver

Stuart.

[Fred]

I'm not sure if this is any use for what I intended to have above (where during cranking the ecu would be able to run on even if the battery voltage went below cutout for the regulator) but these are still very impressive little things and worth keeping in mind for sure :

http://uk.farnell.com/9692681/passives/ ... ecs0hd224v

5v super capacitors. Given what I've seen from 1 Farad at 15V with a massive power hungry amplifier attached playing music softly for over a minute these could work pretty well for us if we sense shut down and go into sleep/wait mode on it.

Admin.

[AbeFM]

Then you have to start looking at current limiting for charging them up, and also something that doesn't "turn on" the ecu until it IS charged up. Things to look at, anyway, as I've seen both of those be big issues in other hardware I've worked on.

[Fred]

I wondered about that. Maybe post a thread on it if you have any details?

[Fred]

Also, I meant full time power to it, just there to really really limit transients and keep the power smooth as silk. battery > regulator > cap etc, without ever powering down, just turn itself off into standby or wait when the key goes off. I guess you still need that stuff though for first time plug ins.

[AbeFM]

Oh, I wasn't picturing it full time powered - I don't really know why you would, anyway.

Er, one thing we did on one board is when we first hit full power then cycle the CPU reset.

Keeping the cap from drawing too much current is a simple matter of a little resistance inline, or some inductance feeding it. The inductive fix would have to be thought out and balanced so it actually helps - the advantage being no wasted energy at run time, the downside being all the math/assumptions.

But basically you have some diode drops or some other form of comparing voltage feed the main power transistor/fet/etc in so the board doesn't get power until the caps are charged. Easy enough to do, but keeps things from disagreeing about what "now" or "5V" is....

[Fred]

http://www.semiconductors.bosch.de/en/3 ... nition.asp

Rumour has it that bip373 is the official replacement for vb921 in the ms camps.

Also, there is lots of interesting stuff in here :

http://www.semiconductors.bosch.de/en/3 ... engine.asp

Admin.

[AbeFM]

Here's a new one.....

I want a computer which is USB powered! At least for writting the flash. It would be beyond awesome to have a USB port in the side, where you plug it into your desktop and write your code to it. Take the power off there.....

Does writing the flash take higher voltage than 5V, or just a "lot" of current.

Or heck, use firewire and use it's many many amps.

[jbelanger]

I have powered my JimStim and MS from this:


Jean

[Fred]

In the event that both are plugged in, I see potential for current flow issues if the voltages don't match up correctly. USB design may have already taken care of that though I guess.

Other than that, our chip draws a bunch more current than an ms2 when it's fired up and humming. I think we discussed this, but I can't remember what the USB specs say a USB port must have. I thought the USB port reported its capabilities though, but there must be an initial current that is common.

Burning flash just uses more current (apparently). The 5v supplied is always the same :-)

Fred.