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?

Using a logical analyser and sigrok I've captured:
2C ITE/TOECU (D0)
3C ETI/TOINV (D2)
4C CLK (D1)
5C STB (D3)

Turned ignition on, turned a/c on, off and then ignition off.
See attachments
I will test sending messages back to inverter using xp677 software and hardware solution from Denso thread ...

Conncted an ardunio nano with software from xp677 on the Denzo ES27C thread https://openinverter.org/forum/viewtopic.php?p=2744#p2744 Edited the software to send all the messages and now the A/C inverter is drawing 0.01 then 0.02 then 0.03 A.


void loop()
{
transferpacket(1);
serialdiag(1 ...

johu wrote: ↑Sat Dec 09, 2023 10:26 pm Not sure what you're trying to achieve on a higher level but if you want only excitation disabled you can switch to SinCos mode

I want to use an external resolver exciter from the Toyota HV ECU so both Toyota HV ECU and OI can use the resolver.

1) Set OI excitation to 10 kHz (can this be done?)

No luck so far changing the OI resolver excitation frequency.
If I comment out line:
https://github.com/jsphuebner/stm32-sine/blob/e0faaf56d222c23cdf5c59b6b5141de99d03656f/src/inc_encoder.cpp#L471
gpio_set_mode(NORTH_EXC_PORT, GPIO_MODE_OUTPUT ...

I'm trying to figure out how make the gates stay permanently low so we can use the A/C compressor inverter as a rectifier without modifications see johu comment here:
https://openinverter.org/forum/viewtopic.php?f=14&p=61039#p61039

- Removed 4 IGBTs of the A/C inverter and replaced them with a ...