Prius Gen 2 inverter logic board

[timh2870]

I have been looking over the forums, Damien's videos, wiring diagrams, etc and I cannot understand why we need to replace the logic board inside the inverter. Maybe I'm missing something glaringly obvious, but it looks like all the necessary control signals are brought out, with the sole exception of high side/low side drive of each phase being reduced to one signal. The factory board does the heavy lifting of driving the gates, providing adequate dead time, preventing desaturation, and overall keeping the magic smoke in. Why change it? What is it that the factory board won't let you do?

My plan is to have a gen 2 inverter driving a gen 3 transaxle's mg2 only. Can I do this with just an external board that replaces the hybrid ecu?

Side note - I have a running and driving gen 2 Prius, with the second inverter coming in the mail. I was going to hook up the gen 3 transaxle to the car's inverter to see If I can make the thing spin. According to Alldata the motor wires are U, V, W in that order, but I can find no markings on the stator or the short bit of harness the scrapyard left me. This gives me 50/50 odds of getting it right the first time... assuming the resolver to stator relationship is the same from gen 2 to gen 3.

[sfk]

Won't it just run backwards if the UVW order is wrong?

[timh2870]

If it was an induction motor, yes. As these are permanent magnet synchronous motors that rely on position feedback, the answer is a slim maybe, but probably not. Either way, I'll find out.

[NiHaoMike]

Since it's a permanent magnet motor, couldn't you check the phase order by connecting an oscilloscope and manually turning the motor?

[SciroccoEV]

There is no logic board in a Gen 2 inverter, just the two intelligent power modules, dual inverter and boost.

[RetroZero]

Is this why the Gen 2 inverter is a less viable /hackable option? The Gen 3 seems less complicated with everything Damien and Johannes have done lately - fully populated boards with all the bells and whistles...
I'll ask anyway, is there no way to 'reverse engineer' the Gen 3 board to suite Gen 2?
(hammer if anyone needs to knock me out for stupid beginner question)

[MattsAwesomeStuff]

Is this why the Gen 2 inverter is a less viable /hackable option? The Gen 3 seems less complicated with everything Damien and Johannes have done lately - fully populated boards with all the bells and whistles...

Nope.

IIRC Damien had, so he made, the Gen 3 board first. Populated boards from that supplier were ridiculously expensive, so he offered bare and populated boards at large price differences.

But, the bare board required SMT soldering skills that were intimidating to newbies. Solder paste and syringes, soldering oven, SMT hot air rework stations, etc.

So, when he next designed the Gen 2 board, he designed it to use only through-hole parts that are more beginner friendly. He used the Blue Pill, which is basically a breakout board for the STM32 (the only component that is only available as SMT). The Blue Pill you then just solder through-hole into the board along with everything else.

Third, he switched suppliers to JLPCB which has such cheap populated boards that they're not longer prohibitively expensive. He redesigned the Gen3 board this way (having to use their limited parts inventory).

Fourth... he plans on doing the same redesign with the Gen 2 boards and selling populated ones for probably the same price of you buying components and populating the naked board yourself. It's on his long list of things to do, and probably a low priority considering anyone pursuing a Prius project can just buy a Gen 3 inverter instead.

I'll ask anyway, is there no way to 'reverse engineer' the Gen 3 board to suite Gen 2?

Gen 2 transaxle? Yes. Just use the Gen 3 inverter.

Gen 3 logic board to control the Gen 2 inverter?

I mean, technically possible, but no, far as I understand they do things differently enough there'd be no point in trying.

If a bunch of us want to throw extra bonus bribe money at Damien to bump up Gen2 pre-populated JLPCB boards on his priority list, he might be bribeable. Otherwise, it's open source, we'll have to be patient and encouraging.

[RetroZero]

Thanks again MattsAwesomeStuff. That clears up alot for me. I'm trying to understand as much as possible before commiting to iether a Damien Board or Johannes Rev 2/3. I see there's more than just 'plug and play' to this now.

[arber333]

Gen2 inverter uses PWM signals to drive transistors differently. It keeps them OFF and signal would mean transistor would turn ON.
Gen3 is more conventional in that brain must command either OFF or ON state.

[RetroZero]

I'm up for bribing, but looking at the crowdfunding for theTesla drive Units, 4 of us would have to dig deep

Since Damien and Johannes are 'working together' on ceating logic boards and software, the 'quickfix solution' could be the Brainboard Rev 3 with the existing Gen 2 inverter current sensor signals modified....? (Brainboard Rev 3 seems very similar to New Gen 3 Populated boards).

I'm not fussy as to whose 'board' I purchase, but am willing to 'donate' if one of them (Damien or Johannes) looses out from a sale. Since it's a joint effort, I would like both of them to feel like their time and EFFORT is worthwhile...

[MattsAwesomeStuff]

Since Damien and Johannes are 'working together' on ceating logic boards and software, the 'quickfix solution' could be the Brainboard Rev 3 with the existing Gen 2 inverter current sensor signals modified....? (Brainboard Rev 3 seems very similar to New Gen 3 Populated boards).

Back in the day, there weren't these options. So Johannes created the Open Inverter hardware and software. The hardware is hardware from scratch.

Damien doesn't do much if any software, he uses the Open Inverter software. Johannes has modified the software a bit (in fact, I think specifically so Blue Pill can work).

I don't think Johannes contributes to Damien's hardware designs though, perhaps beyond whatever Damien got knowledge-wise from the design.

And, no one really builds inverter hardware boards anymore, we just kidnap OEM inverters and throw them in the truck in the night.

[johu]

Yes, well observed thats our mode of collaboration

[RetroZero]

Thanks again for the info. So next question: Wait for new populated Gen 2 boards from JLPCB? I understand they are still in design stage, if any stage since Gen 3 has stolen the limelight

[jnsaff]

JLCPCB only populates Surface Mount components which are mostly pain to solder by hand. Gen2 is through hole only (with the idea that this is easy to do for people like me at home and the only component not available as through hole, the stm32, is on the dirt cheap blue pill) and JLCPCB does not do any soldering on them whatsoever. I have not heard of any plans for a surface mount built and tested Gen2 inverter brain board but I'm sure bribes could work.

All of the other boards also have through hole components (mostly for connectors) and those are soldered by hand after receiving them from JLCPCB.

[RetroZero]

Starting to make sense for Tier 4 beginner
Thanks

[jonarneham]

Hi!
Hav just bought two Prisu gen2 boards and are looking forward to start testing the hack of two gen 2 prius inverters !
Who will be the best to talk to regarding programming of these boards? We are going to use them for powering a tesla model 3 motor, and the next big task is to use the regen capability of the inverter to quick charge a battery pack.....

[RetroZero]

Do you mean the Gen 2 adapter board?

[MattsAwesomeStuff]

Hav just bought two Prisu gen2 boards and are looking forward to start testing the hack of two gen 2 prius inverters !
Who will be the best to talk to regarding programming of these boards?

Did you buy the boards from OpenInverter.org, or from EVBMW.com?

If OpenInverter, they're preprogrammed.

If EVBMW, there isn't support for them beyond forums, but you could try reading through and asking in the appropriate thread: viewtopic.php?f=14&t=228

Or read through the slightly-outdated wiki (connection image is inaccurate): https://openinverter.org/wiki/Toyota_Prius_Gen2_Board

Or you could look through the general wiki to learn how the software works: https://openinverter.org/wiki/Main_Page

Or you'll have to be more specific about what you want or are struggling to program.

[jonarneham]

Hi I bought the open inverter one. and if this already has the program preinstalled I'm fine for the moment

[RetroZero]

If it's the Openinverter Adapter board, check out the link in Main Menu. I just got mine spinning the MG1 motor from 12V supply thanks to forum help.