9160 IO default statue

RE: 9160 IO default statue

lemon — Tue, 22 Dec 2020 01:53:27 GMT

Hi，

Thanks for your reply.

It's very useful.

Brs,

Lemon

RE: 9160 IO default statue

Håkon Alseth — Mon, 21 Dec 2020 10:13:00 GMT

Hi,

[quote user="lemon"]

The firmware is the factory code,and haven't been reprogram.

If I connected the P0.27 to PW_ON,nRF91 couldn't power on, as the VDD3.3_EN cann't enable

the power IC to power the system on.

I guess there is about 13K resistance at P0.27 so that can be 1V .

[/quote]

The nRF is unpowered at this point in time? If so, this is a flaw in your schematic.

By applying voltage directly to a GPIO when the nRF is unpowered, you are powering it through the ESD protection inside the nRF.

By connecting a 100k series resistor, you are restriction the current flow through the unpowered GPIO, and the circuit runs as initially intended.

Kind regards,

Håkon

RE: 9160 IO default statue

lemon — Mon, 21 Dec 2020 08:50:54 GMT

Hi,

The firmware is the factory code,and haven't been reprogram.

If I connected the P0.27 to PW_ON,nRF91 couldn't power on, as the VDD3.3_EN cann't enable

the power IC to power the system on.

I guess there is about 13K resistance at P0.27 so that can be 1V .

Brs,

Lemon

RE: 9160 IO default statue

Håkon Alseth — Mon, 21 Dec 2020 08:30:14 GMT

Hi,

How is the GPIO configured on the nRF side?

If you check the NRF_P0->PIN_CNF[27] register, it should indicate if the pin is configured with input or output, with any corresponding pull-resistor.

39k parallel with a pull-down of approx. 13k gives around 1 V at the PW_ON signal.

It could also be the board setting:

P0.27, if using the nrf9160dk_nrf9160 board, is default set to the UARTE0 RTS pin. Be sure to change this in case HWFC is enabled.

Kind regards,

Håkon

RE: 9160 IO default statue

lemon — Mon, 21 Dec 2020 01:19:18 GMT

Hi，

I have measured R32 and R33 and they are the values as the the schematic shows.

When I cut PW_ON line,It works fine.

Brs,

Lemon

RE: 9160 IO default statue

Håkon Alseth — Fri, 18 Dec 2020 11:42:39 GMT

Hi,

Have you measured R32 and R33 in case they're not the value as stated in the schematic, or if they have switched place?

Kind regards,

Håkon