SparkFun Forums

[JDHawkins]

Hi,

I'm able to power up my OLA using a USB C cable and log data on the SD card when powered in this way.

I've removed the jumper by cutting between the MEAS pins and connect a power supply (3.6V battery and 5V supply) to the Vin pin. When I press RESET, the PWR and STAT lights briefly light up and ~4mA are drawn from either supply. They then switch off and there is no further activity on the board.

Testing the board at various regulator outputs and bypass caps they seem to be at the correct value (3.3V), but the QWIIC power reg, SD power switch and ICM voltage reg are not being enabled by the Artemis.

The RTC seems to hold it's date/time when switching from USB to Vin supplies and back so I think that the backup RTC battery shouldn't be draining/causing the RTC to reset.

Is there any reason why the Artemis would fail to start up, which would cause them momentary flash of the LEDs and leave these power regs disabled? Am I doing something stupid in how I have connected by external supply, or are there further settings that need to be modified in the Terminal config?

Happy to provide more info if useful.

Kind regards,
Jonathan

[PaulZC]

Hi Jonathan,
Apologies for the very slow reply - I've only just noticed your post.
It sounds like the code thinks the VIN voltage is low and is going immediately into sleep.
The Qwiic, SD and IMU power are only switched on if the code gets that far. It sounds like it is going to sleep before then.
Have you got low battery detection enabled in the settings?
Please try resetting the settings to the default (option "r" from the main menu) and see if that makes any difference.
The only other thing it could be is the 3.0V voltage supervisor (U1) telling the Artemis that the 3.3V rail is low, but I can't see how that would happen with the arrangement you've described.
Best wishes,
Paul

[JDHawkins]

Hi Paul,

Thanks for your reply - think I've got to the bottom of this now.

The batteries I'm using have a limited pulse current capacity which was below the initial current (approx 110-120mA?) drawn by the Artemis/OLA peripherals when starting up. We've replaced the batteries with a different model with higher pulse current capacity and able to boot fine.

Adding a couple of electrolytic capacitors (approx 470uF) in parallel with the original battery also worked.

Kind regards,

Jonathan

[PaulZC]

Hi Jonathan,
Thanks for letting us know - glad that's working for you.
All the best,
Paul