Read current of Li-ion battery from fuel gauge(bq40z50r2) in stm32cubeIDE.

[Mohan1]

Hello,

I am trying to get data of battery in stm32cubeIDE,I have taken voltage and temperature of battery successfully but when i was trying to get current of battery, it shows value like 65535 or 65473....like a garbage value.I am reading current in milli ampere.I also checked value on bqstudio as shown below image and it is (-1103mA),negative sign because it is discharging current.

But when i send the register address of current in this same bqstudio,it shows garbage value FBB2 i.e.64434 same as showing in stm32cubeIDE. I have connected load of 5ohm and battery voltage is 3.5v .Please give me any suggestion.

[Pavel A.]

[Mohan1]

Thanks for your response sir,means i am getting current data in 2's complement form .Am i right sir?

[Mohan1]

Please reply sir.

[Piranha]

How about reading the Technical Reference Manual instead of asking questions, which have already been answered?

[Pavel A.]

Yes, the device returns signed 16-bit number.

Sorry, I haven't noticed your reply earlier.

-- pa

[Mohan1]

Thank you so much sir.

[Mohan1]

@Piranha​ Thanks for your reply sir. I already read technical reference manual,in technical reference manual,value of discharge current is given like - Min= -32768mA and max=0mA.

[Piranha · Accepted solution]

TRM in section 14.11 clearly states Min = –32767 mA, Max = 32768 mA, Word protocol and I2 data type, which is explained in section 15.1.2.

[Mohan1]

@Piranha​ Thanks for your reply sir, and negative sign for discharge current ?