I want to run the Nordic Thingy off an external 3.3V supply (i.e. not the Li battery)

[Qualflow]

Can I remove resistor R29 (ENCHG) on the ADP536 to disable the charging function and plug my 3.3V supply into the battery connector?

i.e. use the ADP536 for the power management but without the battery charging function.

Obviously the battery level function would be redundant

This is for an evaluation project, going ahead we would build our own board.

[helsing]

One simple solution here would be to remove the battery and power via USB. However, I assume this is not your preferred option as you probably want to get started developing with the TI part.

Charging with ADP5360 may be disabled with adp536x_charging_enable(false).

Regarding R29: This resistor is already not mounted on HW v1.0.2 of Thingy:91 that I have in front of me.

[Qualflow]

Thanks

I assume the "adp536x_charging_enable(false)" is a nRF9160 command (I'll take a look at the SDK).

I wonder have they connected that ADP536 pin to a pin on the nRF9160 so it would be different from the schematic in the User Guide

[helsing]

The Thingy:91's PMIC is configured in the "secure" board file (nrf/boards/arm/thingy91_nrf9160/board_secure.c). That file contains the power_mgmt_init function, which in turn calls adp536x_charging_enable. That would be a good place to swap true with false.

I will check the schematic. Which user guide revision and which HW version are you working with?

[Qualflow]

Hi,

I'm using v1.4 of the user guide.

The hardware version loos like 1.4.0 (2020 23). I just got it.

I hadn't actually looked for R29 yet I had assumed it would be there

I do have another option for these which is to run it though the mains power/usb and then use the battery as backup/reporting in case someone unplugs it in the field.

Thanks again.