DIYEFI.org Forum

hi,

i did some 40pin adapter to enter a v3.0 board
Could someone please check the schematic so i could finish the board?

i don´t know where the idle-pin on the processor is

thomas

1) Though that CPU *should* work, I can't guarantee it, keep that in mind.
2) Idle pins if PWM idle is any of the HW PWM pins, if that CPU has any. They MAY be multiplexed. Looks like 1,2,3,4,78,79,80 are available, 3 or 4 are better than 4 or 3, Pins 3,1,79,78 should be better than pins 1, 2, 80. If I'm wrong, sorry.

Hopefully Andy and/or Dan will review the rest for you. You may need to provide context about the contents of a V3 board to facilitate this.

Nice solution, BTW :-) A true entry-level FreeEMS setup, if we can make it work.

Fred.

Pin 39 is used for injectors as well ..

I took a quick look at your schematic, it is a neat project

Here are my quick notes:

1. You should consider the 9S12XDT512 microcontroller instead of the 9S12XA512 since you have a CAN IC, but the XA512 doesn't support CAN.
2. Next, your BDM connector pinout looks to be wrong, take a look at the JAGuar schematic at: https://github.com/DeuceEFI/Jaguar/blob ... ematic.pdf
3. I would also add a 1uF capacitor between Vddr/Vssr and add a 1uF capacitor between Vddx/Vssx
4. I would increase R10 and R11 from 4k7 to 10k, you don't need a strong pull up on the MAX outputs, I would also add 1k resistors between the MAX outputs and the Port T inputs to limit the current.
5. Also regarding the MAX IC, you will need to add the other two supply voltage decoupling capacitors as recommended by Maxim IC, again see my MAX circuit in the JAGuar schematic.
6. For your CAN IC, add a 1k pull up resistor to 5v from pin 1.
7. You will also need a 120 ohm terminating resistor between CANH and CANL if this is going to be the first or last device in the CAN network.
8. Take a look at your ground plane fill under the 9S12X MCU, it should look more like the Freescale recommended design as seen in Appendix C, Figure C-3 of the datasheet.
9. Make sure to feed your +5v to the capacitors first, then route to MCU pins (same for MAX IC supply voltage, feed to capacitors first, in order then to IC).
10. Your traces look quite close together under your BDM connector, I would make sure to leave the clearance between traces at 0.17mm to 0.18mm

Well that's all I can see for now.

Great stuff, Andy!

re 1) either should work from fw perspective, but neither is proven.
re 4) definitely add the 1k series limits
re 5) definitely triple decouple
re 9) pay close attention

Fred :-)

DeuceEFI wrote:I took a quick look at your schematic, it is a neat project

thanks

DeuceEFI wrote:Here are my quick notes:...

thank you to have a look
i will check this 10 things

thomas

next try

Question: Are you planning to make schematics/layout available under some license? Or completely closed? I ask because it might be easier to review in a non-PDF environment. What you do with it is entirely up to you, of course.

Some simple things:

FreeEMS, not freeEMS

fur FreeEMS not fur FreeEMScode

CLT >> CHT (Coolant/Head Temperature, it's not just for Coolant, it's a general engine temperature input for warm up purposes of which coolant and/or heads are good indicators)

What exactly are these for:

IDV
IACEN
IAC1
IAC2

Is BP German for Fuel Pump? How about FP Relay instead?

Still no triple decouple on MAX chip.

Please explain what you're doing with BOOT (which should be called Load/CEL) and the BDM header? That pin is both an input AND an output, and must be treated with care.

Fred.

Fred wrote:Question: Are you planning to make schematics/layout available under some license? Or completely closed?

This is just an breakout board for an megasquirt v3.0 board that you can easy test this FreeEMS code
if i did some real hardware i will think about this stuff

Fred wrote:I ask because it might be easier to review in a non-PDF environment. What you do with it is entirely up to you, of course.

i did it in eagle
most of you are using kikad
right?
if someone would ported to kikad he can do
i can load this eagle files up if you want

Fred wrote:Some simple things:

FreeEMS, not freeEMS

fur FreeEMS not fur FreeEMScode

done

Fred wrote:What exactly are are for:

IDV
IACEN
IAC1
IAC2

IDV=IdleValve
IACEN=PWM Spare1
IAC1=PWM Spare2
IAC2=PWM Spare3

If you dislike this MSPinnames i can rename
in hessen germany you say "is mir wurscht"

Fred wrote:Is BP German for Fuel Pump?

in German BP=Benzinpumpe

Fred wrote:Please explain what you're doing with BOOT (which should be called Load/CEL) and the BDM header? That pin is both an input AND an output, and must be treated with care.

i put it there because the pins of the BDM-header were free

thomas

Baldur uses eagle and has lots of MS hardware laying around, he might be interested in sharing a seeed studio batch with you, esp if he can review your work in eagle?

I think it makes the most sense to call those PWM pins what they are, PWM1, PWM3, PWM5, PWM7 or whatever. About this, you've got them on non-optimal pins. See my other post where I researched it for you and swap them.

My late grandmother referred to fuel as Benzine and used to check it in her one-owner 61 beetle by dipping the jack handle in the tank ;-) Still, I think Germans will understand FP Relay and non-Germans won't understand BP, but it's your decision.

Fair enough re the Load/CEL pin, but please rename it. And perhaps put an SMD LED in parallel on the board too? Then you get an "I'm alive" out of it by default.

Are you going to send me a blank board when you have them made? Or will you be making in a very small quantity? I collect FreeEMS hardware ;-)

Fred.