O2Micro OZ890 Based BMS Units

[crossbreak]

u have a PM

 

[Brainfuckr]

Is this your software?
How far did you come? Is it working complete?
Can it be used for I²C transfer by parallel or RS-232 port?

What about the data protection you mentioned?
Does that mean this is used to "dongle" the expensive O2micro-I²C-USB-interface?

Yes this is my own Software written in Python which is communicating via usb serial (RS-232) with an arduino nano which can configure/monitor (1s pulse) the bms via i2c .
Theoretically you can alter all values manually, the read out values are calculated automatically via formulas, i even added an auto connect feature (the program starts and connects instantly to show the bms values, or you can select the detected bms devices manually).
If you change EEPROM settings you need to do a hard reset to make the bms use the new changes, but there is a data protection mechanism which allows a whole rewrite of the ÉEPROM and thus accepting new settings without a hardware reset.

Sorry for answering so late, the project is on ice until we find a supplier for OZ890 chips in order to inspect hardware bugs (i2c port destroyed) and to test behaviour with multiple chips.

 

[powersupply]

Brainfuckr, I'm really interested in your work.
I have a board stuck at 112 degrees (offset, internal temp) which goes to overtemp in no time.
There are several of us with this problem.
Hopefully your great work could rewrite that register.
Do you think your program could run on a $5 Raspberry Pi Zero?
That would be excellent!
Thanks !

 

[circuit]

Have that problem with temperature as well.
I believe it is due to incompatible newer configuration app.

 

[e-doc]

Yes this is my own Software written in Python which is communicating via usb serial (RS-232) with an arduino nano which can configure/monitor (1s pulse) the bms via i2c .

Is it open source?
Can I get the software source code and hardware circuit diagram?
I need to re-compile because I use windows (XP and 7)...

 

[Joost]

Hello all,

Is it possible too retrieve the password from a oz8920/oz890 chip?
Finally I hooked my secondhand BMS (16s LiFePo4) O2Micro OZ8920 with 2 chips on it.
After struggling too communicate over the i2c port I got the addresses chip 1(u2 on the board) has 0x62 chip 2 0x60 (u1 on the board)

I use the smartBMS i2c dongle but I only can read the chip with blocked parameters.
Does someone knows more?