BQ40Z80EVM-020: Cannot Communicate/Wake Device

David Thompson2

Part Number: BQ40Z80EVM-020
Other Parts Discussed in Thread: EV2400, BQ40Z80, BQSTUDIO

I can't get my BQ40z80EVM to talk to BQ STudio using either my own EV2400 or the on-board one. When I press the wake button, it shorts B+ to P+ but P+ returns to 0 when I let go. Even if I hold the wake button down, I can't talk to it.

I've copied the right bqz file to the config folder. I've powered it with a stack of 7 resistors as the guide says the default is a 7s configuration. The top of the stack is supplied with about 24V.

The EV2400 jumpers are configured correctly as far as I can tell (though the setup guide has lots of missing Jumper IDs!)

Any ideas?

over 5 years ago

0 Wyatt Keller over 5 years ago

TI__Guru** 105770 points

Hello David,

Could you share some pictures of your setup with us so we can take a look? Is this a new EVM or had it been working before?

When you plug in the bq40z80 does bqStudio auto detect the gauges firmware or is there no communication at all?

Try upgrading to the test version of bqStudio, some issues were resolved in the latest version. You can also try manually connecting the PACK+ and BAT+ with a wire to see if this wakes up the gauge.

Sincerely,

Wyatt Keller

0 David Thompson2 over 5 years ago in reply to Wyatt Keller

Intellectual 685 points

Sorry for the slow response...

I am using the on-board EVM now. I have a 1k resistor to emulate each of the 7 cells.

Powered from ~25V

Bat+is connected to P+ permanently with a link wire.

BQ Studio detects and reads the FG the first time, but will not do anything after the first read. The reading always timesout or gets not response.

The current meter also jumps around the values of -8191, +8191 or 0 every few seconds

0 Andy Liu (BMS) over 5 years ago in reply to David Thompson2

TI__Guru 52115 points

Can you probe the TS1 pin of the bq40z80 and check if you can see any pulse?

Andy

0 David Thompson2 over 5 years ago in reply to Andy Liu (BMS)

Intellectual 685 points

Yes TS1 is pulsing every 0.5s or so - I assume therefore the device is alive and kicking, just not talking.

0 Wyatt Keller over 5 years ago in reply to David Thompson2

TI__Guru** 105770 points

Hello David,

Can you make sure the jumpers are securely on the SMBus lines? Also connect the "sys pres" in the J11 terminal block to PACK-, this should make it so you don't need to have BAT+ and PACK+ together all the time, just press the button to wake it up.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ40Z80EVM-020: Cannot Communicate/Wake Device