INA226: An error occurred while reading the registers in loop

JY Du

Part Number: INA226

Read bus voltage register(0x02) and power register(03) in loop,calibration register is set 2048 dec,other register is default.

The step is :set(02) read, set(03) read; set(02) read, set(03), read;set(02) read, set(03) read; ........

I want to loop 1000 times ,but there alway an arror occur after random loops.

this is the total loop ,loop gap is 7ms

this is good step

this is an error occured. Program cannot Start for SDA is HIGH,but SCL is low.

There is no other I2C device on the bus. MCU is C8051F340.

over 3 years ago

0 Castrense Nigrelli over 3 years ago

TI__Expert 4720 points

Hello,

In I2C communication the master has control of the SCL line the INA226 can only pull SDA low. Further more if the failure happens the same way as above it looks like if the acknowledgment period is less than ~30us it will fail? On the ninth SCL the INA226 does acknowledge and will relinquish the SDA. The start may need to be adjusted to keep it at around 30us delay. Can you confirm other failures timing?

Regards,

Cas

0 JY Du over 3 years ago in reply to Castrense Nigrelli

Prodigy 10 points

is there any specification required the period of Ack? Here's another error ,just 30us

0 Castrense Nigrelli over 3 years ago in reply to JY Du

TI__Expert 4720 points

Hello,

The wait period for a stop is min 100ns there is no max. What I am saying is the INA does not seem to be the problem. In this failure you have not sent a stop condition the master did not pull sda low.