MRE addon Board - Wideband controller + SD Card slot + EGT Chip

[JRD McLAREN]

It started as a wideband controller form mck1117
on small board with 2x5 pin header, and headers for (rusefi) wideband module
and ended as a compact addon board for microrusEFI.

..but due to lack of goods, and some kind of communication in this thread - https://rusefi.com/forum/viewtopic.php?f=4&t=2200
is no reason to fabricate this boards ... (immediately)

(En attendant Godot)

[JRD McLAREN]

NOW .. on GITHUB ...

https://github.com/JRDMcLAREN/wideband_controller_mre

[AndreyB]

Wow that's pretty cool!!! Let's see how F103 progresses maybe it would become a F103 board soon

[JRD McLAREN]

Thanks ...

I'm not sure, if it will fit into aluminum case, I have plastic one.
And Molex Microfit connector is not waterproof.
(it is not problem in my case)

Has anybody hint for small waterproof one ?

[JRD McLAREN]

another idea...

[MWP]

ESP32 or a BT module?

I gave up on BT modules. Terribly unreliable.

[puff]

with native can bus support onboard, everything else looks excessive
however, to eliminate communications delays, may be other protocols would be more preferable (pure DAC-ADC? PWM-modulated? SPI?)

PS I looked through the source code - why RTOS?

[JRD McLAREN]

ESP32 or a BT module?

I have no problem make it for all ..
BT and ESP32 ...

I gave up on BT modules. Terribly unreliable.

It is depend on each module.
I have "original" HC-05, and it work fine. Many years in VEMS.
Some cheap "BEKEN" are crap, some are good. (firmware..?? )

[JRD McLAREN]

PS I looked through the source code - why RTOS?

this is question for mck1117 ..?? maybe ...?

[JRD McLAREN]

Added K-Thermocouple - MAX31855KASA
(CS is PA15)

[JRD McLAREN]

version with STM32F072C8T6

(somebody must answer the question, "will it drift.?" )

[JRD McLAREN]

new git repo:

new version for STM32F072C6Tx or STM32F103C6Tx MCU in LPFQ42
https://github.com/JRDMcLAREN/mre_addon_board_v2

and old one was renamed to:
https://github.com/JRDMcLAREN/mre_addon_board_v1

[puff]

are you going to use the ready-made firmware, or develop your own one?
afaik, there are no these chips available on jlcpcb, so you can't order assembly. meanwhile, there are still some GD32F190C8T6 left (5V adc and dac!), but they'd probably require some changes in the board layout.

[JRD McLAREN]

I have a plain to use mck1117 firmware .. this one https://github.com/mck1117/wideband/blob/master/for_rusefi/wideband_image_with_bl.bin

I'm not (good) programmer ...
It's too hard to find some MCU everywhere .. SOLD OUT ...
(corona crisis .. or what ... )

I have ordered last 6pcs of STM32F072CBT6 ..and waiting for it ...
but any GD32Fxxx will work too ...
if you can tell me, which one can be used....

[JRD McLAREN]

GD32F190Cx .. looks good ...
except pins 35 and 36 ( PF6 PF7 )

(it will be a BIG problem, when one is connected to GND and other to VDD permanently .. )

[puff]

If it was not the RTOS, it would be probably not that hard to port the code, but so far I haven't seen RTOS code for these chips, so, this would be much bigger task..

[JRD McLAREN]

...kooooonečne je to tu .... . ...

[JRD McLAREN]

first one ...

[JRD McLAREN]

small tutorial

We must pick-up CAN signal from MRE ... from R22 (for explame)
twisted wire are required ...

DSCN5643s.JPG (366.73 KiB) Viewed 54593 times

then solder it to add-on board - CANH & CANL pins

and we need power supply for LSU heater also..
I'm pick it from 12VMREL trace .. R139
and solder it into J21 pin
(all current versions of MRE has not enough trace width on 12V pin - 2x5pin header)

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DSCN5649s.JPG (336.11 KiB) Viewed 54593 times

[JRD McLAREN]

short video:
http://89.173.96.22/dohc/rusEFI/DSCN5651.AVI

[dexter_lab]

Admiration for the efforts and congras for running version. What are going to do with one channel of EGT?
perhaps a stupid question, but if mre is managing 'usually' 4 cylinders it is good to have 4, isn't it?

[JRD McLAREN]

Hmmm .. good question ...

And answer is NO ..
No, you don't need 4 EGT sensors ...

Probably you don't need any EGT sensor, when you have "STOCK TUNED" engine, with stock ECU.
(or good tuned engine)

Is good to have one, just for reference, when you tuning your engine, and is good to have one for your TURBO converted engine.
(NA to TURBO)

Except, if you wish to tune your prototyping engine, on bench, try to run on high-compression lean-mixture ... etc ...

EGT provide good reference for tuning, less for any kind of problem diagnosis ....
..and (my opinion) none for engine safety ...
.. when you see 980 degC, it's too late to do something with "your melted pistons" ...

[dexter_lab]

thank's. I agree with the first part. Beneficial will be to check individual cylinders for lean or miss fire conditions and to take some action. perhaps will be cheaper in terms of software and hardware compare to some fancy ION sense, right?

[puff]

is it not late, when the temperature is 900ºC?

[mk e]

thank's. I agree with the first part. Beneficial will be to check individual cylinders for lean or miss fire conditions and to take some action. perhaps will be cheaper in terms of software and hardware compare to some fancy ION sense, right?

EGT isn't a very good tuning tool, it varies for a lot of reasons and is 2nd or 3rd order indicator of mixtures so not very reliable indicator of that. Aircraft use it as a "something it is wrong" when it changes from baseline. It can also be used to tell use peak efficiency point for spark timing....lowest EGT SHOULD mean the most efficient conversion of heat to power but the actually numbers are engine and cylinder specific. Misfire defection would be hard as temp change happens slowly, but it would spot a chronic misfire.

Not melting a turbo is the most common motorsport use these days I guess.

[JRD McLAREN]

..version 2.3 ...
..on the way ...

[JRD McLAREN]

Small update ...

Mounting on "MRE + SD Card" version is soo easy ..
Just pick it into the MRE board and connect / solder two wires for CAN.

[BeerMoneyMotorsports]

who is producing the board for you? F042 is damn hard to get these days.

[JRD McLAREN]

Me ...

I'm found last 6 pcs of 072CBT, and now is gone ..

..5 was ordered via ebay, and I'm so curious for it ...
(what kind of FAKE it will be)

[JRD McLAREN]

..so 10 pcs mcu from china is here ..
and it looks like genuine ...

DSCN5750.JPG (1.19 MiB) Viewed 52147 times

..now I waiting for PCB ...