This has not yet been tested with a genuine MRE case, only against the case adapter so may need some small changes to suit.
It will need a pretty good printer as the locating tabs on the back part are only 0.2mm smaller than the holes in the front plate and the spacing between the 8 holes is only 1mm.
I have an Opel CIH engine, which I intend to use as testbench for a microrusEFI. I am new to automotive electrical installations and I would appreciate some help.
How is the supply power intended to work?
Should the starting key switch in the car close a circuit and power the µrusefi through pin1. The µrusefi the closes a hold circuit with Main relay pin29. With the main relay closed, pin5 gets 12V.
Do you have any general schematics for the engine control system?
Should the starting key switch in the car close a circuit and power the µrusefi through pin1. The µrusefi the closes a hold circuit with Main relay pin29. With the main relay closed, pin5 gets 12V.
Do you have any general schematics for the engine control system?
if a main relay is used its' purpose is to make the EFI be able to power down and switch of the supply by itself, right?
Not exactly. rusEfi does not power down main relay explicitly - it's the ignition key which powers down ECU and once ECU is off it no longer keeps relay on, and relay gets shut off.
Re: microRusEfi
Posted: Fri Mar 13, 2020 5:31 am
by AndreyB
TC2030-MCP-NL cable was a success. Have not got TC2030-CLIP yet so had to hold it while programming but at least schematics and PCB are totally functional.
On my piece the wiring was following (I've cut the RJ connector and soldered directly to ST-Link)
GND black
+3v blue
SCK red
SWDIO yellow
NRST green
SWIM white
Re: microRusEfi
Posted: Fri Mar 13, 2020 5:45 am
by AndreyB
0.4.8 extra vias have dropped Q1 temperature by 7C, is that a reasonable number?
both boards naked, both boards turned on at the same time running same self-stimulating code using similar wall power supplies. Room temperature +20C.
0.4.7 Q1 hottest spot ~60C
0.4.8 Q1 hottest spot ~53C
Anyway, if a main relay is used its' purpose is to make the EFI be able to power down and switch of the supply by itself, right?
//Andreas
That is technically possible with the hardware today, but not implemented in software (yet, relatively low priority). The other reason for the existence of the main relay pin is reverse-polarity protection for high current stuff like the ETB driver. Using a diode would have a ~0.7 volt drop, which at the few-amp draw of a electronic throttle would mean having to deal with an extra watt or two of heat. Because of this, the MR supply pin is NOT reverse protected like the ignition pin. You could theoretically wire both pins together (to the ignition switch), but that would risk completely destroying the ECU in case of reversed power supply (battery).
Re: microRusEfi
Posted: Fri Mar 13, 2020 10:09 am
by kb1gtt
So 60C - 20C, is a 40C rise when PCB is naked. AEQ ambient is 85C, so 85C + 40C is 125C, which I believe is above the desired max temperature for the naked 0.4.7 board. I generally attempt to design with a PCB temp below 105C as there are some MFG's that have PCB's which are only rated for 105C. It is very common a PCB is rated for 150C. So I would like to see it below 105C, but it's not critical to be that low. Also in reality, this board is not naked, it has an alum heat sink. So you are close to the thermal limits even when naked, but in reality, your not naked. This looks like it is fine when under normal conditions. Perhaps for comparison you could put it on just the back plate and see what temp you get. Also are you clicking some injectors and similar tasks? Or is the just running idle?
I think the via's are good, and will be helpful for when and if MRE is used on adapter boards which may not have the same heat sink. Even naked the 0.4.8 looks like it's max ambient is around 115C, which is a very common design limit, as well 85C ambient is decently hot. Most will not actually reach this limit. I bet we are below the 105C once the 0.4.8 is put on either the alum back plate, or the adapter PCB's.
Re: microRusEfi
Posted: Sat Mar 14, 2020 12:53 am
by AndreyB
Now same boards bolted to cases with a plastic film spacer.
That is technically possible with the hardware today, but not implemented in software (yet, relatively low priority). The other reason for the existence of the main relay pin is reverse-polarity protection for high current stuff like the ETB driver. Using a diode would have a ~0.7 volt drop, which at the few-amp draw of a electronic throttle would mean having to deal with an extra watt or two of heat. Because of this, the MR supply pin is NOT reverse protected like the ignition pin. You could theoretically wire both pins together (to the ignition switch), but that would risk completely destroying the ECU in case of reversed power supply (battery).
They're both reverse protected to 12V_SAFE, but not to 12V_MREL. The ETB H-Bridge is directly connected to the 12V_MREL pin on the connector without a diode. D36 is not for reverse protection, but to prevent the ignition switch from powering the rest of your car backwards through the 12V_MREL pin.
Re: microRusEfi
Posted: Sat Mar 14, 2020 6:53 am
by Andreas_28023
OK
//A
Re: microRusEfi
Posted: Sun Mar 15, 2020 9:53 pm
by AndreyB
With 0.4.8 having a few more parts populated by JLC only 208 pads over 13 components have to be added to finish assembly in VR configuration.
I think we have IO unbalance on MRE. 2 LS is too little while 10+4 analog inputs is too many. Shall we convert two analog input pins into two high-current low side outputs?
Re: microRusEfi
Posted: Tue Mar 24, 2020 8:43 pm
by AndreyB
Complete used harness for Lada could be acquired for about $15 in some parts of the world. On same Lada vehicles ECU is in the cabin (unline Nissan ECU in dirty engine bay) so we get pretty clean crimped connector with about 30 wires already in it. The missing wires could be taken from the smaller ECU connector. You can even build most of your new complete custom harness from this Lada harness!
With a utility knife you need to cut 4 keys from inside the male part to mate default microRusEfi connector with a brown plug. Two center keys could be left as is.
One day someone would have to do it using Gimp ideally.
Same price but cheaper shipping.