OPT9221 - Can't Write to some TG Registers

Ishwarya Ananthabhotla

Other Parts Discussed in Thread: OPT9221, DRV2605, DRV2605L

Hi,

I am using the OPT9221 on a custom board. But I've recently noticed an issue where reading out the contents of both register banks (0x5C and 0x58) gives the correct default contents for the DE banks, but not the TG. In fact, I cannot read anything but zeros from, or write, about 2/3 of the TG register bank. So I'm not able to generate any frames from the camera. Has this issue been seen before?

Thanks.

over 9 years ago

0 Anand Gadiyar over 9 years ago

TI__Genius 15005 points

Do you have a DRV2605 haptic driver on the same I2C bus?

There was a report that this IC responds on 0x58 as well and causes a conflict with the OPT9221.
e2e.ti.com/.../1575428

0 Ishwarya Ananthabhotla over 9 years ago in reply to Anand Gadiyar

Prodigy 30 points

Yes, I do in fact-- and I've read that post and disabled the haptic driver by bringing the enable pin low, but I still see the problem. Any other thoughts?

Thanks.

0 Anand Gadiyar over 9 years ago in reply to Ishwarya Ananthabhotla

TI__Genius 15005 points

Do you have a list of all the slaves connected to the same I2C bus as the OPT9221?

0 Ishwarya Ananthabhotla over 9 years ago in reply to Anand Gadiyar

Prodigy 30 points

Continuing along this thread, I've gone ahead and removed the DRV2605L from the system-- it turns out that even though it was disabled, it was preventing the TG register bank from being written to (!). All register values are now what they should be according to the datasheet, but no frames are being delivered. Initialization sequence appears to be correct. Any thoughts?

Thanks.

0 Anand Gadiyar over 9 years ago in reply to Ishwarya Ananthabhotla

TI__Genius 15005 points

For the OPT9221, the bare minimum register setting to start modulation and data output after reset is just to set tg_dis = 0.

If you do not initialize any other registers and only set tg_dis = 0, do you see any activity on the illum_p/illum_n signals, and on the output lines?

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OPT9221 - Can't Write to some TG Registers