openinverter forum

Hello All.

Inquiring to see if we can set some requirements for a 'Mini' Zombieverter.
I'm careful not to fork and crowd this space too much; but I seem to think that there's some space in the Stm32-vcu line for a non-toyota focused VCU, while still maintaining compatibility with the project as a whole.

I've been holding off this as the IO requirements were a bit difficult to make universal, but with Johannes and adding flex IO in the next release, It's becoming flexible enough to have universal IO.

Initial Ideas:

• Leverage Zombieverter Schematics and BOM, maintaining Part designation # to aid troubleshooting/mods across lines

• 48 pin ECU using extremely cheap AliExpress ECU enclosure - https://www.aliexpress.com/item/32839361268.html

• Make footprint match 10cm2 limit for cheap JLCPCB assembly

• Use BOM items for JLCPCB Assembly service

• Downsize some SMD to 0602

• 2 layer board?

• Integrated ESP32 to align with other projects

Of course keeping this Opensource, Fully giving credit to Damien and team for the Stm32-vcu project.
At least hoping this fork isn't frowned upon.

I looked at doing something silmilar but there were too many compromises needed, for me, to keep it compatible with the zombieverter firmware.
The same processor would need to be use as some important signals are on port PD and PE which are not available on the 64 pin package.

I am still interested in whether this can be achieved but am more likely to go in my own direction.

I would implore you not to do this unless you can guarantee firmware compatibility. Much better that we have more people contributing to the same thing, and are those UART components to support the Toyota hardware really so big and expensive? Unless you need to add something, I feel like you'd be better just building a normal Zombie and simply removing the parts you don't need.

My view is slightly different, I would quite like a compact vcu that does not have any inverter related features but provides a bms interface (battery interface, soc calculation, contactor control), manages the charge pilot lines, controls a charger, handles control of cooling (pump, fan control), does cabin climate control (about 3 separate LIN bus ports and quite a few temperature measurements in my case) and also provides rf comms into the vehicle. It would need to be permanently powered with a low power consumption.

The existing VCU is over the top in some areas while not catering for others so I had been planning to do something similar to what's proposed based on the STM32L4 family to get quiescent power consumption down to mA or so.

Great points to consider all around.

I do fear that more forks of hardware will dilute the whole ecosystem, the main purpose was basically to get the board assembly cost down to $100 or so, shrinking the size to make custom boards easier while still using the same circuitry.
My ultimate goal is to size a VCU footprint to allow the copy-paste of the circuit into a factory ECU enclosure (such as mentioned in the other connector thread). Adding the options I need for future additions; likely using a 2nd processor connected via CAN.

Whatever we do, we'll likely need to stay within the 100 pin parts. Can confirm that the VCU Bin file won't boot on a 64 pin part without modification
Trying to hold back just making a whole new board using a overkill MCU such as the F7... Could likely get it to work, but keeping up with updates and making it worthwhile from a community standpoint dilutes the space even more.

Maybe efforts are better focused on an I/O expander board to complement the ZombieVCU?

I'll release what I pull together over the holiday, It may prove beneficial to the group... If anything It'll be a KiCAD port for the existing ZombieVCU schematics for those to use in their own projects.