bq27542-G1 SE pin as interrupt

David Cohen

Other Parts Discussed in Thread: EV2400, BQSTUDIO

What are the required pack configuration register settings needed to get the SE pin to toggle from a HIGH to a LOW when the SOC1 flag changes state?

I can manually toggle the pin through the bqStudio interface connected to an EV2400 module that is connected via I2C to my application circuit, and I can see the SOC1 flag change state in the bqStudio display when it should during battery discharge. I know the chip and the SE pin physically work.

I can toggle registers, I have the actual gas gauging function working properly, etc., I just cannot seem to make the SE pin toggle from SOC1 changing state during discharge.

What am I doing wrong? I do not see what is wrong with the register settings I'm using based on what I have read in all the documentation for this part.

Any help is appreciated. Thank you.

-David

over 9 years ago

0 Fernando Lopez over 9 years ago

TI__Expert 8230 points

Hello David,

A couple bits must be set to use the SE pin for interrupts, here's the configuration I tested on my EVM:

INTPOL = 1 (assuming you want an active high when the interrupt is asserted, if you want active low, set this to 0)
INTSEL = 0
HOST_IE = 1 (this is the HOSTIE in Configuration>Registers>Pack Configuration, bit4)
In Configuration>Registers>Pack Configuration D, I changed the following:
- SE_POL = 1
- SE_PU = 1

The tricky part is making sure that the interrupt you care for is the one toggling the SE pin. There are some interrupts that take priority over the SOC1 interrupt. For example, the SOC1 flag activates two interrupts: the regular SOC1 alarm and the BTP alarm. If BTP_EN is set, this means that the BTPSOC1 set/clear threshold will take priority over the regular SOC1 set/clear thresholds. If you just want to use the regular SOC1 alarm, disable the BTP_EN interrupt.

Please refer to the following table for the interrupts and which one takes priority.