nRF9160 DK v0.8.5

nRF9160 DK board control

The nRF52840 controls analog switches on the nRF9160 DK, enabling routing of some of the nRF9160 GPIO pins to onboard functionality, for example LEDs, or the regular GPIO interfaces.

For details on which GPIOs on the nRF9160 can be routed by these analog switches, see the table below.

Table 1. Board control routing
Name nRF52 switch control Source nRF9160 Destination
Default1 Optional
nRF91_APP1 P1.14 P0.26 Interface MCU VCOM0 RTS P27 6
P0.27 CTS P27 7
P0.28 TX P27 8
P0.29 RX P1 4
nRF91_APP2 P1.12

(P0.12; see footnote)

P0.01 P14 2 Interface MCU VCOM2 RXD
  P0.00 P14 1 TXD
  P0.15 P10 2 RTS
  P0.14 P10 1 CTS
nRF91_LED1 P1.05 P0.02 - LED1 P14 3
nRF91_LED2 P1.07 P0.03 - LED2 P14 4
nRF91_LED3 P1.01 P0.04 - LED3 P14 5
nRF91_LED4 P1.03 P0.05 - LED4 P14 6
nRF91_SWITCH1 P1.09 P0.08 - SWITCH1 P19 1
nRF91_SWITCH2 P0.08 P0.09 - SWITCH2 P19 2
nRF91_BUTTON1 P0.06 P0.06 - BUTTON1 P14 7
nRF91_BUTTON2 P0.26 P0.07 - BUTTON2 P14 8
nRF91_GPIO P0.13 P0.17 P10 4 nRF52 P0.17
P0.18 P10 5 P0.20
P0.19 P10 6 P0.15
NRF91_TRACE P0.24 P0.21 P4 TRACECLK nRF52 P0.22
P0.22   TRACEDATA0 P1.04
P0.23   TRACEDATA1 P1.02
NRF91_COEX P1.10 COEX0 P1 COEX0_PH nRF52 P1.13
The name to be used when referring to this signal path and the configuration needed to control it.
nRF52 switch control
The GPIOs on nRF52840 that are used to control the analog switches selecting between default and optional routing.
Source nRF9160
The GPIOs on nRF9160 that can be configured to have an alternative routing.
Destination "Default"
The default destination for the "Source nRF9160" if the "nRF52 switch control" pins are set as output and pin driver is low.
Destination "Optional"
The optional destination for the "Source nRF9160" if the "nRF52 switch control" pins are set as output and pin driver is high.

The setup described as "Destination Default" in the table above is active if all the GPIOs on nRF52840 listed as "nRF52 switch control" are set as output and driven low. There is a pull-down resistor on the switch control lines, and therefore, "Destination Default" can also be received if the control lines from the nRF52840 are not driven. If the optional routing is desired, the "nRF52840 switch control" pins have to be set as outputs and driven high.

The nRF52840 is preprogrammed with firmware that provides the default destination setting. Configurable code examples for the nRF52840 allowing to change the board routing can be found in the nRF Connect SDK. After the changes are done, the new program must be compiled and programmed to the nRF52840.

Note: To program and debug the nRF52840, nRF52 needs to be selected on the PROG/ DEBUG switch (SW5).

Since this firmware in the nRF52840 decides the nRF9160 DK behavior, it is vital that it is always present in the nRF52840. If it is accidentally erased or firmware affecting the use of the key nRF52840 GPIOs is programmed in, nRF9160 DK functionality is not guaranteed. In such cases, nRF52840 needs to be preprogrammed with the default board control firmware from the nRF Connect SDK.

1 For nRF91_APP2, two GPIOs need to be set high on nRF52840 to get the optional destination for the signals.