Hi manifold,
Super cool project!
Any progress on the sp51 battery?
(Sorry just saw your message above)

Anyone have a toyota prius gen2 inverter controller opening inverter board version 1.3 I can borrow or buy?

r1ckyb0nd wrote: ↑Sat Aug 30, 2025 9:33 pm Does this code allow you to use the prius battery pack natively?

yes, visual for integration with OI see https://github.com/hakanrolsson/stm32-c ... prius-gen2
For info on the battery ecu's can messages, see http://www.eaa-phev.org/wiki/Prius_PHEV ... #CAN_Tools

I've made a A0 poster for the Prius gen2 stuff will print if OK:
https://docs.google.com/presentation/d/ ... ue&sd=true

Wrote a small Prius Battery ECU decoder using an ESP32 and a couple of 3.3V Can Boards before I get ahead of my self over sharing the Toyota hybrid batteries:

// === ESP32 Prius CAN Parser ===
// Monitors Prius Gen2 Battery ECU on 2 CAN buses

#include <ACAN_ESP32.h>
#include <mcp_can.h>
#include ...

Had a busy couple of days working on the project. I replaced and balanced the cars original battery pack with some used ones I picked up. With the rest of the modules I started rebuilding a 2nd pack. I worked on the test setup for boost charging using the A/C inverter. I got as far as contactors ...

Working on setting up boost charging, using a Denso 13140-0050 current sensor. Converting the Denso 13140-0050 output 5V to 0V (0A at ~2.5V) to 0V to ~2.5 for the gen2 board using an esp32:

// === Pin Definitions ===
const int adcPin = 34; // ADC1_CH6 (GPIO34) — input: 0…2.5 V
const int dacPin ...

Making my way through pcb errors... Plan is to implement charging updates and A/C inverter support. Plan is to use an esp32 for A/C support but open for suggestions. Could also use same ecu as Zombieverter and make a mini Zombie?

Testing Prius gen 2 on pcb for Zombiverter enclosure.

johu wrote: ↑Tue Mar 18, 2025 7:31 pm I didn't think of that aspect. Will you test this?

Yes

Hmm, time for an update to this thread. After getting nowhere with trying to keep the HV ECU happy, I started on implementing/reverse engineering of functionality of the HV ECU. I picked the A/C control , as others on the forum had made some progress on the A/C Denso ES27C .

Implement the ...

OK, so I have a solution that kind of works to control the A/C compressor inverter. I took the messages from the TIS run and the Arduino program and converted it to esp32 that have a Wi-Fi module and made an interface similar to TIS. Roughly mapped messages with RPM (still haven't fully decoded the ...

1️⃣ Create a wiring diagram in KiCad.

https://github.com/hakanrolsson/Prius-Gen2-A-C-compressor-inverter/blob/main/Prius-Gen2-A-C-compressor-inverter.pdf


Can this be integrated into the existing hardware/software for the Prius Gen 2 board, or is something standalone needed?

In my opinion ...

https://i.imgur.com/pcGgvaM.png

What in the unholy Cthulhu hell of Mom's Spaghetti...

I noped right out of trying to understand it, and skipped right forward to appreciating whatever it is that was done.

This is a man in the middle board for toyota prius gen2 HV ECU see https://github.com ...

Success! It Works! 🎉

We can now control the Gen2 A/C compressor inverter! 🚗💨

🔗 Arduino code & logs: GitHub Repository

Also, I figured out the CRC codes using ChatGPT:
Byte 5 = (B1 ≪ 1) ⊕ B2 ⊕ B3 ⊕ B4

📌 Next Steps
1️⃣ Create a wiring diagram in KiCad .
2️⃣ Decode the log: AC on for real ...

Finally managed to capture logs of the A/C turning on for real.
I did this using my 5V logical analyzer with a CD4504B voltage level shifter.
There was some noise, which I filtered out.
Now, I'm trying to figure out the CRC and send back ETI messages using an Arduino Nano.

Sigrok files attached ...

Have you figured out how to start the air conditioning compressor? What is the communication protocol of the air conditioning compressor?

Making some small progress as mentioned previous in this thread it's some kind of SPI interface.
See script below for Ardunio Naon that can decode and reply ...

Thank you WOSS for confirming. I'm now trying to figure out how to update the Arduino software from the ES27C thread to use an incoming clk instead of sending the clk.

Hmm, I didn't expect the CLK signal to come from the inverter.

turnip73 wrote: ↑Fri Dec 29, 2023 4:39 pm From the Denzo ES27C thread seems I now need to connect high voltage to get the inverter to wake up.

High voltage is ~40V.

I'll make it.

Was setting chargecur to 0 via CAN ever implemented or how does the BMS/stm32-car terminate the charging?

Using https://github.com/hakanrolsson/stm32-car/tree/prius-gen2 (this code get the charge current from the Toyota Prius BMS CAN messages)
configure to send to stm32-foc:
can tx chgcurlim 4 0 ...

Observations:
1) I'd say my A/C pressure switch is gone when I bypass it the A/C start https://www.youtube.com/watch?v=S0LwTq7qKi0.
2) If your hybrid battery is bad the car will not run A/C https://www.mavyn.com/blog/decoding-p0a80-code-on-toyota-prius-fixes-causes
3) I was using an SFH618A ...

Was setting chargecur to 0 via CAN ever implemented or how does the BMS/stm32-car terminate the charging?

johu wrote: ↑Fri Jun 19, 2020 4:28 pm When AC is unplugged the inverter will power down and all contactors open. Same when BMS commands end of charge - which can also happen by setting chargecur to 0 via CAN

No luck testing in the car. I tried with both msb and lsb from captures... Any ideas?