[DRIVING] VX220 with Tesla SDU

Tell us about the project you do with the open inverter
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catphish
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Re: VX220 with Tesla SDU

Post by catphish »

janosch wrote: Fri Oct 07, 2022 1:56 pm Nice sandwich! Source code and everything, great, I will dive right in!
I should probably mention, because it's not obvious. The way the pins happened to line up, the serial RX and TX on the CAN board become the +3v3 and GND supplies to the display. These pins are shorted to the supply as shown, and just left floating by the MCU.
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Re: VX220 with Tesla SDU

Post by 7yatna »

Hi Catphish,

really awesome work, I`ve been looking at your progress and funny enough i keep stumbling across you on different platforms.

Here, DIY electric, even FB EV conversions.

now i`m buttoning up my beetle. got my first motor spin yesterday and hopefully finishing up the reset of wiring in a week or two.

I'm experiencing similar problems on the SDU performance/settings.

and i want to update the FW to the latest revision that came out last week 5.20R-2.

i understand it is as simple browsing the FW file from the web interface then upload ?

or there is some tricky things ? I keep seeing comments about bricked SDUs. the tiny beetle has the motor berried deep and don't want to get it out again.

and can you please share your latest parameters?

i will tune and post mine after i get it rolling.

but for now here is my config

Tesla SDU
3x BMW 530E pack in parallel (356 Nominal)
Tesla Gen2 Charger
Tesla DC DC Converter
Full coolant Loop.
multiple custom made micro controllers PCBs for other peripherals.
the packs are running on its own BMS.

Thanks,
Karim
Hammer, Duct tape, WD-40 that`s it :D
1973 Beetle with SDU swap.
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Re: VX220 with Tesla SDU

Post by catphish »

7yatna wrote: Wed Oct 12, 2022 10:35 pm and i want to update the FW to the latest revision that came out last week 5.20R-2.
i understand it is as simple browsing the FW file from the web interface then upload ?
or there is some tricky things ? I keep seeing comments about bricked SDUs. the tiny beetle has the motor berried deep and don't want to get it out again.
Yes, the firmware upgrade process is as simple as uploading the sine.bin file.
But... you MUST fully disconnect the high voltage before doing this. Flashing the firmware with HV connected will almost certainly destroy your inverter.
Also, no matter how tempting it is, don't set tripmode to open the contactors under any circumstances, this usually does more harm than good.
7yatna wrote: Wed Oct 12, 2022 10:35 pm and can you please share your latest parameters?
I've attached the full parameters pulled directly from my car. I've been using these parameters for daily driving for about a month now. They are designed for 300V. They *should* also work fine at 360V, as things should scale up automatically but I can't provide any guarantees of this. This config is designed to pull 500A peak, so be sure your battery can handle that. I suspect most packs can.
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Re: VX220 with Tesla SDU

Post by 7yatna »

Hi Catphish,

Yes i`m aware of the trip mode and flashing with HV voltage on.

i have designed my system that it requires about 3 different stages of contactors to close after the manual switch to energize the motor.

i will use your parameters and will adjust to my system.

still need about a week or two before test driving. finalizing other things but we do have a spinning system :D

i will update

thanks again.
Karim
Hammer, Duct tape, WD-40 that`s it :D
1973 Beetle with SDU swap.
espriev
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Re: VX220 with Tesla SDU

Post by espriev »

What a great looking project!
I am considering something similar, how has it been working out running the SDU reversed now that you have had it on the road for a while?

Thanks!
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Re: VX220 with Tesla SDU

Post by catphish »

espriev wrote: Wed Jan 04, 2023 12:25 am I am considering something similar, how has it been working out running the SDU reversed now that you have had it on the road for a while?
It's done a few hundred miles and I haven't had any issues at all yet. No signs of oil loss and it still sounds like it's running smoothly :)
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Re: VX220 with Tesla SDU

Post by espriev »

That's very encouraging to hear!
I have been working my way through your threads here and on DIY electric car, thank you for posting in so much detail. Extremely helpful to someone like me.
From what I have read so far, the sum total of what you did to set up "reversed" SDU use was to modify the oil pump (no small task, but nothing like rearranging the inverter to motor connections!) and modify parameters.
Is this correct?
Thanks again!
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Re: VX220 with Tesla SDU

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espriev wrote: Wed Jan 04, 2023 2:04 pm That's very encouraging to hear!
I have been working my way through your threads here and on DIY electric car, thank you for posting in so much detail. Extremely helpful to someone like me.
From what I have read so far, the sum total of what you did to set up "reversed" SDU use was to modify the oil pump (no small task, but nothing like rearranging the inverter to motor connections!) and modify parameters.
Is this correct?
Thanks again!
That's correct. All you need to do is modify the oil pump.

No electrical changes are needed as long as you're using an openinverter logic board (the stock tesla control board can't run in reverse). Openinverter actually runs the SRDU backwards by defualt anyway, but if it goes the wrong way, all you need to do is swap the forward and reverse switch inputs and it will go the other way.

Note there is no software setting to reverse the motor, one of my small jobs to improve opinverter in the near future is adding this option, but it's not essential as you can always just swap the direction switches to make it go the other way.
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Re: VX220 with Tesla SDU

Post by espriev »

A few questions, as your build is similar to what I am doing your experience would be of great help to me.
Maybe I can add some of this to the WIKI as I seem to be spending a lot of time searching for this information and some will apply to all builds.
#1, what gauge wire did you wind up using for the various low voltage connections to the TESLA SDU board?
Did you use an analog accelerator pedal, and did you find it necessary to use shielded wiring for the inputs?
I have seen some posts about risk of catastrophic failure from using a single potentiometer analog accelerator interface.

Thanks!
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Re: VX220 with Tesla SDU

Post by catphish »

espriev wrote: Fri Jan 06, 2023 9:26 pm #1, what gauge wire did you wind up using for the various low voltage connections to the TESLA SDU board?
I used 0.5mm^2 cable for all new low voltage wiring. 10A is more than enough to power the SDU inverter.
espriev wrote: Fri Jan 06, 2023 9:26 pm Did you use an analog accelerator pedal, and did you find it necessary to use shielded wiring for the inputs?
The VX220 already has has a dual analog accelerator pedal. I wired up both potentiometers to the SDU.
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Re: VX220 with Tesla SDU

Post by espriev »

Nice! Drive by wire already...
So that seems to equate to 22 gauge in these here parts, pretty small wire. Now I can order the connector pins!
Is the dual pot pedal for redundancy? If that's the case I could just use a dual 10k pot, for me it would be easier than fitting a Tesla (or other EV) pedal. Adapting a throttle cable to a pot is very easy.
No interference issues requiring shielded cable?

thanks again!
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Re: VX220 with Tesla SDU

Post by espriev »

How are your range results turning out?
I hear rule of thumb is 2-3 miles per battery kWh, is that close to what you get?
Another forest I am not seeing for the trees, is the WiFi interface simply a dumb terminal?
My experience being in FI/ICE setups, I am used to having a program running on a laptop, that reads data from the system and can adjust parameters then save them to the system's dedicated microprocessor. I have yet to find the way this system / interface works simply explained, but as I see no software downloads just firmware it is making me think it is a terminal.
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Re: VX220 with Tesla SDU

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espriev wrote: Fri Jan 06, 2023 10:49 pm Is the dual pot pedal for redundancy? If that's the case I could just use a dual 10k pot, for me it would be easier than fitting a Tesla (or other EV) pedal. No interference issues requiring shielded cable?
Openinverter uses the dual pot in a redundant manner. I'm not 100% sure what happens if one fails (probably a safe shutdown). I've not had any issues with interference. I don't know what value pot the VX220 throttle uses. 10k is probably fine. Lower values are less susceptible to interference but I h aven't noticed any.
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Re: VX220 with Tesla SDU

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espriev wrote: Sat Jan 07, 2023 3:49 am How are your range results turning out?
I hear rule of thumb is 2-3 miles per battery kWh, is that close to what you get?
I believe I get about 4 miles per kWh when driving efficiently, which is probably above average for a conversion. This is a very light car.
espriev wrote: Sat Jan 07, 2023 3:49 am My experience being in FI/ICE setups, I am used to having a program running on a laptop, that reads data from the system and can adjust parameters then save them to the system's dedicated microprocessor. I have yet to find the way this system / interface works simply explained, but as I see no software downloads just firmware it is making me think it is a terminal.
Openinverter boards come with a wifi module that provides a web interface for tuning. See https://openinverter.org/wiki/Web_Interface
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Re: VX220 with Tesla SDU

Post by 7yatna »

Charlie,

Glad to hear your conversion is going great,

mine is OK As well except couple of hiccups due to the insane rain we got here in San Diego.

I've done about 1000 Miles on the car so far., yes i was commuting to work in it about 60 miles a
day.

up until last week was driving the car but i blew the charger logic board due to the rain and water soaked inside the charger. my insulation didn't go as good as i expected.

my car is pretty much Ludacris mode, i do about 2.8 miles per kWh. but I'm doing 0-60 in about 4.2 and cruise the beetle with flat windshield at 75 mph.

well need to do full thread after revivng it back and getting it back on the road.

thanks,
Karim
Hammer, Duct tape, WD-40 that`s it :D
1973 Beetle with SDU swap.
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Re: VX220 with Tesla SDU

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catphish wrote: Sun Jan 08, 2023 4:01 pm Openinverter uses the dual pot in a redundant manner. I'm not 100% sure what happens if one fails (probably a safe shutdown). I've not had any issues with interference. I don't know what value pot the VX220 throttle uses. 10k is probably fine. Lower values are less susceptible to interference but I h aven't noticed any.
Hi, thanks for such a great write up and info on your build (also on DIY Elec Car)- it's helped me figure out quite a few things already. I have a 6pin dual pot type Tesla pedal and an OI inverter (just swopped in the OI board today!) and I'm trying to figure out the wiring of the pedal as you have so as to use the redundancy as you mentioned. I've obviously been through the pin out and mini wiring diagrams on OI and I've hunted but are there any wiring diagrams or pics or info you could point me to for this? Would really be appreciated :D
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Re: VX220 with Tesla SDU

Post by espriev »

I have now installed the OI board, obtained the control port connector, and a Subaru accelerator pedal (with mating connector & pigtail!).
I confirmed the pin-out of the pedal, all that is required is a +5 VDC power source and a DC volt meter. You can get a rough idea with a meter reading ohms, there should be 2 sets of 3 pins, and there should be no resistance between any pins from 1 set to the other.
On the pedal pins, I got 610K between OUT & GND, and 5k9 between OUT and +5VDC (166ohms between +5 & Ground).
Just hook up +5 VDC (bench supply, 3 AA batteries in series, what have you... anything close but not over +5 VDC will do) and GND and meter between OUT and GND. It seems you can't do any damage by hooking it up wrong, when you hook it up correctly you should see the output go from around 0 VDC to +5 VDC with pedal fully down.

catphish, are you using the accelerator pedal to trigger regen? Per usual, I see all sorts of different ways here of using the dual element accelerator pedal, but most agree that the way the OI board works is that there is only 1 analog accelerator pedal input and those who are using both pedal elements are either using an outboard multiplexer to get 1 signal out of both (and reduce inaccuracy) or using 1 set to the O/I input pin 8 and the other to pin 10 (instead of using pin 10 for a brake pressure sensor input to control regen).
Also, is there anything you can suggest for the initial test bed set-up?
As I understand it, under normal operating conditions the O/I controls the pre-charge and main contactors, but for low motor voltage testing the precharge contactor must be manually operated, so run the coil GND to a switch to engage it (2nd after connecting +12 VDC to pin 13)?
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Re: VX220 with Tesla SDU

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espriev wrote: Fri Feb 03, 2023 4:08 pm On the pedal pins, I got 610K between OUT & GND, and 5k9 between OUT and +5VDC (166ohms between +5 & Ground).
This doesn't sound correct. Assuming this is just a variable resistor, the largest resistance should be between +5V and GND.
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Re: VX220 with Tesla SDU

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espriev wrote: Fri Feb 03, 2023 4:08 pm catphish, are you using the accelerator pedal to trigger regen? Per usual, I see all sorts of different ways here of using the dual element accelerator pedal, but most agree that the way the OI board works is that there is only 1 analog accelerator pedal input and those who are using both pedal elements are either using an outboard multiplexer to get 1 signal out of both (and reduce inaccuracy) or using 1 set to the O/I input pin 8 and the other to pin 10 (instead of using pin 10 for a brake pressure sensor input to control regen).
Openinverter has 2 analog inputs, You can only configure them two ways:
1) Use both analog inputs for a dual output throttle.
2) Use one for the throttle and the other for a brake pressure sensor.

Assuming you have a dual pot throttle, and no brake pressure sensor, you should connect both throttle outputs to the two analog inputs of openinverter. If you do have a brake pressure sensor, then just use a single throttle output, or maybe connect them in parallel. When configuring the software, you can choose to dedicate a portion of the throttle travel to regen if you wish.

Personally I don't use regen at all.
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Re: VX220 with Tesla SDU

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espriev wrote: Fri Feb 03, 2023 4:08 pm Also, is there anything you can suggest for the initial test bed set-up?
As I understand it, under normal operating conditions the O/I controls the pre-charge and main contactors, but for low motor voltage testing the precharge contactor must be manually operated, so run the coil GND to a switch to engage it (2nd after connecting +12 VDC to pin 13)?
I always use a full set of contactors for bench testing, and I control them automatically, exactly the same way as in the vehicle. Is there a reason you don't want to do that?
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Re: VX220 with Tesla SDU

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From the Tesla Setup FAQ:
" You will need to perform a manual precharge or set UDCSW to about 10v less than your test voltage"
There are so many posts stating a variety of "if you do this you will blow up the entire unit" things that I feel very cautious about setting up the test bed properly.

I was wondering how you use regen in your set-up.
Ideally I would like a paddle control for regen, using a stalk on the steering column. I can easily plumb a pressure sensor (got one off my old Jag..) into the brake line, but having driven a car with paddle control I prefer it to "one pedal" or regen triggered off the brakes.
The Tesla and the Subaru pedal use hall effect sensors (that replicate the circuit of a potentiometer) but supposedly are less likely to "blow up the entire unit" than a pot. Then there are those who say "if you don't use both elements for the accelerator function you might BLOW UP THE ENTIRE UNIT! (I wish there was a WIKI on "Don't do this so you do not Blow Up The entire Unit!")
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Re: VX220 with Tesla SDU

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espriev wrote: Fri Feb 03, 2023 5:55 pm From the Tesla Setup FAQ:
" You will need to perform a manual precharge or set UDCSW to about 10v less than your test voltage"
There are so many posts stating a variety of "if you do this you will blow up the entire unit" things that I feel very cautious about setting up the test bed properly.
There's nothing wrong with using the normal precharge mechanism. You will need to set UDCSW to your low voltage to allow the precharge to complete, but nothing dangerous about that. Just remember to set it back to the correct high voltage value afterwards.
espriev wrote: Fri Feb 03, 2023 5:55 pm I was wondering how you use regen in your set-up.
Ideally I would like a paddle control for regen, using a stalk on the steering column. I can easily plumb a pressure sensor (got one off my old Jag..) into the brake line, but having driven a car with paddle control I prefer it to "one pedal" or regen triggered off the brakes.
The Tesla and the Subaru pedal use hall effect sensors (that replicate the circuit of a potentiometer) but supposedly are less likely to "blow up the entire unit" than a pot. Then there are those who say "if you don't use both elements for the accelerator function you might BLOW UP THE ENTIRE UNIT! (I wish there was a WIKI on "Don't do this so you do not Blow Up The entire Unit!")
As I said above, I don't use regen at all. In fact I use a custom firmware that doesn't even have regen. However, you can absolutely connect a thumb switch to the brake pressure input and control regen that way.
You're not going to damage anything by using only one accelerator channel. The only risk is that your accelerator fails and sticks on (they have 2 channels so one can be verified against the other), but as long as you have a brake switch, you can always hit the brake to stop if that ever happens.
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Re: VX220 with Tesla SDU

Post by espriev »

By brake switch are you referring the "brake pressure sensor signal" normally fed to input pin #10 or an emergency system disconnect switch?
In my old conversion there is a big 2 pole switch between the front seats that the traction batteries go through, push the big red button for emergency disconnect.
It seems like they way to do that now is to have the power / ground to the main contractors go through an emergency disconnect switch and an impact switch.
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Re: VX220 with Tesla SDU

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espriev wrote: Fri Feb 03, 2023 10:46 pm By brake switch are you referring the "brake pressure sensor signal" normally fed to input pin #10 or an emergency system disconnect switch?
In my old conversion there is a big 2 pole switch between the front seats that the traction batteries go through, push the big red button for emergency disconnect.
It seems like they way to do that now is to have the power / ground to the main contractors go through an emergency disconnect switch and an impact switch.
The brake switch is a separate digital input. You connect it to the switch on your brake pedal and it kills the accelerator when it's pressed. You can always turn off the ignition in an emergency to open the contactors but this will often destroy Tesla drive units.
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Re: VX220 with Tesla SDU

Post by espriev »

Is that pin 15 of the 20 way molex "brake light switch"? I thought that was going to the brake light to illuminate it when regen hits, is there a signal for this?
Is there a power down sequence? This possibility you mention of destroying the drive unit by turning it off at the wrong point is one of those "blow up the entire thing" things I hope to wrap my head around, it is turning off the "ignition" (+12 VDC to pin 13) while the motor is spinning that is the dangerous condition? As I understand it turning the system on is +12 to the relays and pin 13, then press "start" (pin 9 to +12). To turn off disconnect +12 to everything (after direction is "off" as in neither forward or reverse is selected? must that be the same to turn on?)
Lots of stupid questions, I know, but if it keep me from blowing it up...
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