Another New Member!

[RobTurbo]

Hi, I've found my way here from the mx5nutz forum, where another member posted about this ECU and I had to have a play!

So far I've ordered a couple of Frankenstein boards and had an STM32F4 Discovery delivered the other day, I haven't had much time to have a good look at it, I have a house that needs work which takes priority, and my mx5's engine is in bits at the minute, which obviously needs sorting before this ECU can do anything on it. I have another couple of engines that I'd like to get running on this, just as toys really!

Looking forward to getting the rest of the bits so I can get cracking with it.

[kb1gtt]

Welcome along.

Do you have specific goals for an engine build, or something similar? Schematic or general layout, things like that.

[RobTurbo]

At the minute my mx5 is running on megasquirt (1, v3), It's a '91 mk1 1.6, I've fitted a proper TPS to replace the original switch and removed the AFM, once I've finished changing the water pump and timing belt I'll be making a start on fitting a turbo. I believe the cam sensor isn't the same as the later model, like sturovo's. It's still wasted spark for the time being but at some point I'll be fitting COP.

I'm aiming to start the car with this ECU once the water pump and timing belt is back on, then swap back to the megasquirt before fitting the turbo, unless this ECU makes a lot of progress before I get around to the turbo, which is entirely possible. If I do temporarily swap back to megasquirt, my brother also has a mk1 1.6 mx5 and will more than likely use one of the ECU's I build while I'm not using it, it will be more suited to his car at the minute, with his being standard engine wise.

[kb1gtt]

Ah, great so I hear CAM / Crank are hall, and the coil driver is integrated into the coil. The rest is the same old same old sensors. Are you using the OEM harness or did you make your own with DB connector for the MS?

What features would you need for the turbo. If you mention them here, russian might start developing the software. Also what do you need for hardware to control the turbo? I'm assuming your looking for some kind of waste gate control.

[RobTurbo]

Yes, the CAS sensor is hall, 2 triggers, I can't remember off the top of my head how many teeth there are on the trigger wheels, I think it's 4 and 1, it's been a while since I looked into it.

There is a separate ignition amplifier, when I switch to COP I'll be getting coils with built in driver, so still no need for drivers in the ECU. The original IAT sensor was in the AFM, I've already got the measurements for the replacement to use with this ECU (I needed them for the MS), CLT is the original, again I have the measurements to use with the ECU. I'm using the OEM harness, I made a short harness that plugs into the OEM ECU plugs and into the MS, this time I'm trying to fit the ECU into and OEM ECU case so will still be using the same harness.

For the turbo, the main feature needed would be Speed Density algorithm, I don't know if there's plans to build a MAP sensor into the ECU or if it would be an external unit, I'm guessing more likely external. Initially the turbo will be running without ECU control, but when I need waste gate control it will be via a PWM solenoid.

[kb1gtt]

It sounds like this should be fine from a hardware perspective. You should be able to use a low side drive for waste gate PWM. The software shouldn't be very hard either. I think russian hasn't done the speed density yet as it is not needed for his immediate needs, and it's a good place to get someone else involved in the code. It really shouldn't be very hard to copy his fuel code and change the algo to make it speed density. How's your coding, is that something you might consider taking a stab at?

Do you know the turbo's inductance, resistance or the period for the duty cycle? If not we can make a guess, but it would be good if we had more data before we start making guesses. Do you have a basic system schematic? Have you seen my start at a system schematic done in DIA? http://rusefi.com/forum/viewtopic.php?f=3&t=360&p=7540&hilit=system+schematic#p7540

[RobTurbo]

It's been a while, but I'm back for round two!

I didn't get anywhere with this the first time around because some of the components I ordered to build the two rusEFI boards were the wrong size, so I couldn't assemble the board, I intended on coming back to it when I had more time, but ended up with less and less time, the mx5 ended up being locked away while life threw all kinds of curve balls at me, then before I knew it almost 4 years have gone by.

I recently decided to make time for myself, with the main focus being the mx5, as I started getting back into the swing of things I remembered the rusEFI, since starting I've moved house and misplaced most of the components, I think I know where the PCBs are but that's about it. Once I looked into it I found that not only are full kits now available, there's also a new version that plugs straight into the mx5!

I'm planning on leaving the Frankenstein boards for now and instead buying a Frankenso kit, but first I need to know the car is still ok, the last thing I did before locking the car away was fit new silicon hose set, coolant pump and timing belt kit, then ran up to temperature a couple times, then locked up and abandoned for a few years, so I'm hoping all is well, after it had been left for a while I disconnected the battery, but as I found out today that didn't stop it dying, there wasn't even enough power to put the lights on the dash, I've put the battery on charge, I'll try again tomorrow, once I see it's all running ok still I'll get ordering.

Andrey told me 90% of the kits are never assembled, I hope to make it into the 10%!

[kb1gtt]

The battery is likely toasted at this point. Open up the caps on top and see if you see the sulfur crystals. You won't be able to get them back. Lead acid batteries need to be cycled to prevent this crystallization.

[RobTurbo]

I figured it would probably not hold a charge anymore, but I’m trying the free option first, I’m going to try it shortly. I can borrow another battery but it’s much larger and won’t fit into the space enough to reach the battery leads, I don’t mind leaving the battery on the floor and bridging the gap with jumper cables if I need to for the time being, I don’t need to drive anywhere, just see it run.

[RobTurbo]

Much to my surprise the battery started the car!

I had a rake through some boxes and found my STM32F4 Disco board, two Frankenstein 0.11 boards and a bag of components, somehow they were all in separate boxes . I didn't find the ECU plug or the two ECU connector PCBs that I had though, I'll have another look for them if/when I come to need them, I'm still planning on a Frankenso kit for my mx5.

I seem to have only bought enough components to build one of the Frankenstein boards, I don't remember why, maybe because I only had one disco board, I'll probably get another when I order the Frankenso kit, or maybe I'll try building it onboard. The Frankenstein (once built) can be for my brother if he ever gets his mx5 a new engine, but that's another story!

I went through the bag of components and picked out the 1206 SMD components and made a list of the 0805 equivalents on mouser, along with a couple MPXH6300AC6U MAP sensors, I'll get the order put in once I'm sure I don't need anything else.

I put the rusEFI firmware on the disco board and had a poke around in the settings, I've done about all I can until I get a board built though.

[AndreyB]

on eBay they sell "2300pcs SMD 0805 50 value Resistor +40 value Capacitor Kit" which I believe is good enough for Frankesntein or Frankenso build

[RobTurbo]

Thanks for the pointer, that works out a lot cheaper.

So if I buy the basic kit and get the caps and resistors from ebay, the only other parts I'll need are the schottky diodes for analog inputs, or are they included in the kit (they're not listed on the kit page)?

[AndreyB]

not in the older version of the kit maybe by mistake but also a bit optional, was since included in frankenso kit wgich still recommend since connector and power supply.