work in progress microRusEfi

Hardware inside and outside of the ECU
User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Fri Aug 09, 2019 6:14 pm

Information for the guy behind https://www.homebuiltairplanes.com/foru ... nes.29814/

PCB side male connector alone weights 34 grams.
MRE v0.1 assembled in Seattle with connector weights 66 grams.

It could be that running assembled ECU without connector weights 31 grams?
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Sat Aug 10, 2019 1:27 am

Progress/test harness/issues

Note that only 4 yellow LEDs are blinking

https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
kb1gtt
contributor
contributor
Posts: 3407
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: microRusEfi

Post by kb1gtt » Sat Aug 10, 2019 9:30 am

Do I see the injector blinking light is wired as noted in this sketch?
Test_Fixture_Sketch.png
Test_Fixture_Sketch.png (9.19 KiB) Viewed 248 times
Also see this picture for a suggested strain relief method. This works better than hot glue.
PCB_Strain_Relief.jpg
PCB_Strain_Relief.jpg (192.86 KiB) Viewed 248 times
Also dental floss is very important.
Welcome to the friendlier side of internet crazy :)

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Sat Aug 10, 2019 1:18 pm

Nope, here is how this is connected. The left resistor was added because LED was pretty bright even in OFF state, barely getting brighter in ON mode. Now with the left resistor, I get proper on/off light.

This style of stitching would require drilling and probably dust :( But yes that was considered.
Attachments
8888_test_harness.jpg
8888_test_harness.jpg (126.85 KiB) Viewed 239 times
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Sat Aug 10, 2019 8:29 pm

Some firmware progress!

https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
kb1gtt
contributor
contributor
Posts: 3407
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: microRusEfi

Post by kb1gtt » Sat Aug 10, 2019 11:24 pm

Glad to hear you got it working with a leakage resistor. That is better, as the light is more intuitive than my schematic. Mine was inverted.
Welcome to the friendlier side of internet crazy :)

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Mon Aug 12, 2019 12:43 am

+12v into each of the connector +5v lines was a success - MRE has survived.

Wiring GND and +12v was a success - MRE has survived.

Looks like we are ready for 0.3

https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Thu Aug 15, 2019 1:39 pm

@abricosvw reminded me to run a longevity test. microRusEfi powered from +12 has blinked LEDs overnight just fine!
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

mck1117
running engine in first post
running engine in first post
Posts: 227
Joined: Mon Jan 30, 2017 2:05 am
Location: Seattle-ish
Soldering skill: yes
Coding skill?: yes

Re: microRusEfi

Post by mck1117 » Thu Aug 15, 2019 8:21 pm

I've left mine running for several days with the trigger simulator running the whole time without issue! Powered from +12v.

mck1117
running engine in first post
running engine in first post
Posts: 227
Joined: Mon Jan 30, 2017 2:05 am
Location: Seattle-ish
Soldering skill: yes
Coding skill?: yes

Re: microRusEfi

Post by mck1117 » Thu Aug 15, 2019 8:28 pm

This got posted on Facebook, but not in this thread!

microRusefi has now run an engine! Last week I successfully wired and started my Volvo b230 on microRusefi serial number 1.



Since the engine was already running on Frankenso, the tune ported over with almost no effort, and the engine appears to behave exactly the same on the new ECU. Success!

The engine is a 2.3 liter 4 cylinder, running sequential fuel and wasted spark ignition (in two-wire mode, so four independent coils).

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Mon Aug 19, 2019 12:26 am

Naive thermal test:

Q1 seems to be the hottest component at 20C-25C above ambient. That's with rear side of the shell acting as radiator.

Without the rear plate I've seen Q1 at 45C above ambient - 25C+45C=70C on a bench with no load on the MRE.



https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
russian
Site Admin
Posts: 9525
Joined: Wed Aug 28, 2013 1:28 am
Location: Jersey City
Soldering skill: yes
Coding skill?: yes
Contact:

Re: microRusEfi

Post by russian » Mon Aug 19, 2019 1:17 am

Also first start with case painted orange!



Sweet MAF oscillation at maximum data rate.
Attachments
javaw_3jLnNtZjbC.png
javaw_3jLnNtZjbC.png (130.39 KiB) Viewed 102 times
2019-08-18_MRE_NA6_starting_running.msl
(4.15 MiB) Downloaded 1 time
https://rusefi.com/s/howtocontribute
very limited telepathic abilities - please post logs & tunes where appropriate - http://rusefi.com/s/questions
my skype is arro239

User avatar
kb1gtt
contributor
contributor
Posts: 3407
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: microRusEfi

Post by kb1gtt » Mon Aug 19, 2019 3:40 am

Does 8888 and/or stm32 have internal temperature sensors? Those would tell you better if there is a thermal problem. With only half the case it is not really correct.
Welcome to the friendlier side of internet crazy :)

User avatar
kb1gtt
contributor
contributor
Posts: 3407
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: microRusEfi

Post by kb1gtt » Mon Aug 19, 2019 3:42 am

What does your no load claim for volts and amps? Aka power supply numbers.
Welcome to the friendlier side of internet crazy :)

mck1117
running engine in first post
running engine in first post
Posts: 227
Joined: Mon Jan 30, 2017 2:05 am
Location: Seattle-ish
Soldering skill: yes
Coding skill?: yes

Re: microRusEfi

Post by mck1117 » Mon Aug 19, 2019 4:17 am

Stm32 does. 45-50c internal stm32 temperature is consistent with what I've seen running on 12v, sitting on carpet with only the bottom half of the case.

My board pulls just shy of 300mA. So Q1 is dissipating (12v-6v) * 300mA = 1.8W.

The 8888 should be dissipating around 0.3 watt in its regulator, plus whatever other current it's drawing (perhaps another half watt, at most)

The 3.3v regulator and STM32 account for the vast majority of the remaining 1.5 watts.

User avatar
kb1gtt
contributor
contributor
Posts: 3407
Joined: Tue Sep 10, 2013 1:42 am
Location: ME of USA
Contact:

Re: microRusEfi

Post by kb1gtt » Mon Aug 19, 2019 5:24 am

Don't I recall q1 is switching? Aka power does not directly mean voltage by amps. Well instantious yes but not on a longer time basis like a linear. I wonder if we can decrease the watts with a faster q1. Also I understand D1 gets hot. Perhaps that would have some thermal via's.
Welcome to the friendlier side of internet crazy :)

mck1117
running engine in first post
running engine in first post
Posts: 227
Joined: Mon Jan 30, 2017 2:05 am
Location: Seattle-ish
Soldering skill: yes
Coding skill?: yes

Re: microRusEfi

Post by mck1117 » Mon Aug 19, 2019 5:49 am

Q1 doesn't switch. The tle8888 is using Q1 as an external linear regulator to get the dissipation out of the tle8888 itself, then doing the precise 6v -> 5v regulation internally.

Per the tle8888 datasheet, page 58:
A linear pre-regulator with an external logic level power MOSFET is implemented to keep the power dissipation of the TLE8888-1QK low.
Infineon recommends the IPD30N06S2L-23, which we are using.

Besides, if q1 was switching, then where would all the extra power be going? 4 watts is waaaay above the peak dissipation of the stm32, which is the only thing actually doing any work on the board. Even if it isn't operating fully steady state, it's still spending its entire existence within the linear (ohmic) region, so it's just a resistor. Faster or slower won't save you.

I've also scoped the gate pin (and output), and they're dead steady. It really is operating steady state. No fluctuation.

mck1117
running engine in first post
running engine in first post
Posts: 227
Joined: Mon Jan 30, 2017 2:05 am
Location: Seattle-ish
Soldering skill: yes
Coding skill?: yes

Re: microRusEfi

Post by mck1117 » Mon Aug 19, 2019 9:33 am

kb1gtt wrote:
Mon Aug 19, 2019 5:24 am
Also I understand D1 gets hot. Perhaps that would have some thermal via's.
Yes - D1 is also dissipating maybe 1/10 watt, but it has almost no thermal conduction to the case, and almost all the conduction it has is to the already-hot Q1. Probably a better plan to investigate using a pfet instead, since that will cut total dissipation instead of trying to dissipate from D1 to the case.

Post Reply