• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 63 subscribers
  • Views 302 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ27510 Inconsistent Communication

Aaron Burnie
Prodigy 140 points
Other Parts Discussed in Thread: BQ27510, BQ34Z100, EV2400

Hello all,

I am writing to see if anyone else has had any issues with inconsistent I2C data communication between the EV2300 and fuel gauge?

I am seeing on most reads through the evaluation software that only half of the flags/ status bits are read.
On some lucky occasions all flags are read.

The image attached below just shows how half are read and half aren't.

Does anyone have any ideas as to why this could be occurring.
Using the same board I have placed other IC's (BQ27510) with no problems. After resoldering the IC due to writing bad data to the flash I cannot get consistent comms. I have ensured solder joints are ok as well under a microscope.

Aaron

  • 0
    Intellectual 300 points

    I had similar output with a bq34z100 talking to an EV2400 via I2C. The bq34z100 was resetting every second due to a design flaw (missing capacitor across the LDO pin - REG25 in my case). An oscilloscope showed that the LDO output (REG25) was not stable. The DataRAM display showed random but consecutive blanks (missing values) on the display. The chip was resetting coincident with the normal flash update (every second for the bq34z100), so when I put it in ROM mode the chip stopped resetting, and I could read the .senc file. Because this was a design problem, all my boards showed the same symptoms.

    It sounds like you have had success with other ICs on your board, so maybe you are seeing a different problem than I did.

  • 0
    Genius 3970 points

    As said before, it'd be good to check the VREG25 rail on an oscilloscope to see if any problems show up there. Additionally, use a logic analyzer to probe the I2C lines and see if glitches are showing up there.

    Looking at the flags and values that are read, the data doesn't look right. The voltage is 1.706 V, reporting discharge while reading 0 mA, and has both the full-charge (FC) and critically-low-charge (SOCF) flags set at the same time.

  • 0 in reply to en-US
    Prodigy 140 points

    Thanks for the replies,

    The data is not right because there are issues with the communications, however after looking at the SDA and SCL they look good.

    I have a 1uF Cap on the output of the Vreg2.5 and input of the regulator. However there was a noticeable glitch in the power supply whereby periodically it would fall to a level which could cause a reset.

    I am yet to look into this further as I have found another way to get around the issue but have found 2 of my prototype boards exhibiting this issue.

    Aaron