User's Guide

Hardware description
The device to be programmed is selected by the SWD SELECT switch (SW2). The selection of device can
also be controlled by connecting TP28 to 1.8 V or ground.
Figure 35: SWD SELECT switch
The SWD interface of the nRF9160 can also be connected to the nRF52840. The enabling of this
connection is controlled by the nRF52840.
Figure 36: SWD interface and control schematic
6.12 Interface
To enable the user to connect external hardware, Nordic Thingy:91 routes some of the GPIOs to
connectors or test points and transistors to drive higher currents.
6.12.1 N-MOS transistors
Nordic Thingy:91 is equipped with four N-MOS transistors that can be used to drive small DC motors
or LEDs. The drain and source of the transistors are available on external connectors and the gate is
connected directly to the nRF9160.
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